ccv_cnnp_model_gradient_checkpointing.c

Bug Summary

File:	nnc/ccv_cnnp_model_gradient_checkpointing.c
Warning:	line 75, column 1 Assigned value is garbage or undefined
Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-unknown-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name ccv_cnnp_model_gradient_checkpointing.c -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=none -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -target-feature +sse2 -tune-cpu generic -debugger-tuning=gdb -fdebug-compilation-dir=/home/liu/actions-runner/_work/ccv/ccv/lib/nnc -fcoverage-compilation-dir=/home/liu/actions-runner/_work/ccv/ccv/lib/nnc -resource-dir /usr/local/lib/clang/19 -I ../ -I /usr/local/cuda/include -D HAVE_CBLAS -D HAVE_LIBPNG -D HAVE_LIBJPEG -D HAVE_FFTW3 -D HAVE_PTHREAD -D HAVE_LIBLINEAR -D HAVE_TESSERACT -D HAVE_AVCODEC -D HAVE_AVFORMAT -D HAVE_AVUTIL -D HAVE_SWSCALE -D HAVE_SSE2 -D HAVE_GSL -D HAVE_CUDA -D HAVE_CUDNN -D HAVE_NCCL -D USE_SYSTEM_CUB -I /usr/local/include -internal-isystem /usr/local/lib/clang/19/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/12/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O3 -ferror-limit 19 -fgnuc-version=4.2.1 -fskip-odr-check-in-gmf -vectorize-loops -vectorize-slp -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/liu/actions-runner/_work/ccv/ccv/_analyze/2024-10-21-122132-109054-1 -x c ccv_cnnp_model_gradient_checkpointing.c
1#include "ccv_nnc.h"
2#include "ccv_nnc_easy.h"
3#include "ccv_nnc_internal.h"
4#include "ccv_internal.h"
5#include "_ccv_cnnp_model.h"
6// This can be removed once we organized ccv_cnnp_apply_gradient_checkpoints better.
7#include "_ccv_nnc_symbolic_graph.h"
8 
9void ccv_cnnp_model_gradient_checkpoints_cleanup_after_build(ccv_cnnp_compiled_data_t* const compiled_data, ccv_nnc_symbolic_graph_t* const graph)
10{
11	ccv_array_t* const gradient_checkpoints = compiled_data->gradient_checkpoints;
12	if (!gradient_checkpoints || gradient_checkpoints->rnum == 0) // No saved gradient checkpoints, this is an easy way out.
13		return;
14	int i, j;
15	const ccv_nnc_tensor_symbol_info_t* const tensor_symbol_info = (const ccv_nnc_tensor_symbol_info_t*)ccv_array_get(graph->tensor_symbol_info, 0)((void*)(((char*)((graph->tensor_symbol_info)->data)) +
 (size_t)(graph->tensor_symbol_info)->rsize * (size_t)(
0)));
16	// Go through to check if any tensors that supposes in this map is removed.
17	for (i = 0; i < gradient_checkpoints->rnum; i++)
18	{
19		ccv_cnnp_model_gradient_checkpoint_t* const checkpoint = (ccv_cnnp_model_gradient_checkpoint_t*)ccv_array_get(gradient_checkpoints, i)((void*)(((char*)((gradient_checkpoints)->data)) + (size_t
)(gradient_checkpoints)->rsize * (size_t)(i)));
20		for (j = 0; j < checkpoint->tensor_symbols->rnum; j++)
21		{
22			ccv_nnc_tensor_symbol_t* const symbol = ((ccv_nnc_tensor_symbol_t*)ccv_array_get(checkpoint->tensor_symbols, j)((void*)(((char*)((checkpoint->tensor_symbols)->data)) +
 (size_t)(checkpoint->tensor_symbols)->rsize * (size_t)
(j))));
23			if (symbol->d >= 0 && symbol->d < graph->tensor_symbol_info->rnum)
24				// If it is dead, we need to remove this symbol.
25				if (CCV_NNC_TENSOR_SYMBOL_IS_DEAD(tensor_symbol_info[symbol->d].flags)((tensor_symbol_info[symbol->d].flags) & CCV_NNC_TENSOR_SYMBOL_DEAD
))
26				{
27					symbol->d = -1;
28					symbol->graph = 0;
29				}
30		}
31	}
32}
33 
34typedef struct {
35	ccv_array_t* outgoings;
36} ccv_nnc_graph_exec_symbol_reverse_t;
37 
38typedef struct {
39	ccv_cnnp_model_gradient_checkpoint_build_context_t tensor_context;
40	ccv_array_t* graph_exec_symbols;
41	ccv_nnc_graph_exec_symbol_new_hook_f old_graph_exec_symbol_new_hook;
42	void* old_graph_exec_symbol_new_hook_context;
43	ccv_array_t* all_tensor_symbols;
44} ccv_cnnp_gradient_checkpoint_build_t;
45 
46static void _ccv_cnnp_gradient_checkpoint_tensor_symbol_new_hook(void* context, const ccv_nnc_tensor_symbol_t symbol, const ccv_nnc_tensor_param_t info, const char* const name)
47{
48	ccv_cnnp_gradient_checkpoint_build_t* const build_context = (ccv_cnnp_gradient_checkpoint_build_t*)context;
49	if (build_context->tensor_context.record)
50		ccv_array_push(build_context->tensor_context.tensor_symbols, &symbol);
51	ccv_array_push(build_context->all_tensor_symbols, &symbol);
52	if (build_context->tensor_context.old_tensor_symbol_new_hook)
53		build_context->tensor_context.old_tensor_symbol_new_hook(build_context->tensor_context.old_tensor_symbol_new_hook_context, symbol, info, name);
54}
55 
56static void _ccv_cnnp_gradient_checkpoint_tensor_symbol_alias_new_hook(void* context, const ccv_nnc_tensor_symbol_t symbol, const ccv_nnc_tensor_symbol_t from_symbol, const int ofs[CCV_NNC_MAX_DIM_ALLOC(12)], const int inc[CCV_NNC_MAX_DIM_ALLOC(12)], const ccv_nnc_tensor_param_t info, const char* const name)
57{
58	ccv_cnnp_gradient_checkpoint_build_t* const build_context = (ccv_cnnp_gradient_checkpoint_build_t*)context;
59	if (build_context->tensor_context.record)
60		ccv_array_push(build_context->tensor_context.tensor_symbols, &symbol);
61	ccv_array_push(build_context->all_tensor_symbols, &symbol);
62	if (build_context->tensor_context.old_tensor_symbol_alias_new_hook)
63		build_context->tensor_context.old_tensor_symbol_alias_new_hook(build_context->tensor_context.old_tensor_symbol_alias_new_hook_context, symbol, from_symbol, ofs, inc, info, name);
64}
65 
66static void _ccv_cnnp_model_gradient_checkpoint_graph_exec_symbol_new_hook(void* context, const ccv_nnc_graph_exec_symbol_t symbol, const ccv_nnc_cmd_t cmd, const ccv_nnc_tensor_symbol_t* const inputs, const int input_size, const ccv_nnc_tensor_symbol_t* const outputs, const int output_size, const char* const name)
67{
68	ccv_cnnp_gradient_checkpoint_build_t* const build = (ccv_cnnp_gradient_checkpoint_build_t*)context;
69	ccv_array_push(build->graph_exec_symbols, &symbol);
70	if (build->old_graph_exec_symbol_new_hook)
71		build->old_graph_exec_symbol_new_hook(build->old_graph_exec_symbol_new_hook_context, symbol, cmd, inputs, input_size, outputs, output_size, name);
72}
73 
74KHASH_MAP_INIT_INT(ccv_cnnp_tensor_symbol_map, int)typedef struct kh_ccv_cnnp_tensor_symbol_map_s { khint_t n_buckets
, size, n_occupied, upper_bound; khint32_t *flags; khint32_t *
keys; int *vals; } kh_ccv_cnnp_tensor_symbol_map_t; static inline
 __attribute__ ((__unused__)) kh_ccv_cnnp_tensor_symbol_map_t
 *kh_init_ccv_cnnp_tensor_symbol_map(void) { return (kh_ccv_cnnp_tensor_symbol_map_t
*)calloc(1,sizeof(kh_ccv_cnnp_tensor_symbol_map_t)); } static
 inline __attribute__ ((__unused__)) void kh_destroy_ccv_cnnp_tensor_symbol_map
(kh_ccv_cnnp_tensor_symbol_map_t *h) { if (h) { free((void *)
h->keys); free(h->flags); free((void *)h->vals); free
(h); } } static inline __attribute__ ((__unused__)) void kh_clear_ccv_cnnp_tensor_symbol_map
(kh_ccv_cnnp_tensor_symbol_map_t *h) { if (h && h->
flags) { memset(h->flags, 0xaa, ((h->n_buckets) < 16
? 1 : (h->n_buckets)>>4) * sizeof(khint32_t)); h->
size = h->n_occupied = 0; } } static inline __attribute__ (
(__unused__)) khint_t kh_get_ccv_cnnp_tensor_symbol_map(const
 kh_ccv_cnnp_tensor_symbol_map_t *h, khint32_t key) { if (h->
n_buckets) { khint_t k, i, last, mask, step = 0; mask = h->
n_buckets - 1; k = (khint32_t)(key); i = k & mask; last =
 i; while (!((h->flags[i>>4]>>((i&0xfU)<<
1))&2) && (((h->flags[i>>4]>>((i&
0xfU)<<1))&1) || !((h->keys[i]) == (key)))) { i =
 (i + (++step)) & mask; if (i == last) return h->n_buckets
; } return ((h->flags[i>>4]>>((i&0xfU)<<
1))&3)? h->n_buckets : i; } else return 0; } static inline
 __attribute__ ((__unused__)) int kh_resize_ccv_cnnp_tensor_symbol_map
(kh_ccv_cnnp_tensor_symbol_map_t *h, khint_t new_n_buckets) {
 khint32_t *new_flags = 0; khint_t j = 1; { (--(new_n_buckets
), (new_n_buckets)|=(new_n_buckets)>>1, (new_n_buckets)
|=(new_n_buckets)>>2, (new_n_buckets)|=(new_n_buckets)>>
4, (new_n_buckets)|=(new_n_buckets)>>8, (new_n_buckets)
|=(new_n_buckets)>>16, ++(new_n_buckets)); if (new_n_buckets
 < 4) new_n_buckets = 4; if (h->size >= (khint_t)(new_n_buckets
 * __ac_HASH_UPPER + 0.5)) j = 0; else { new_flags = (khint32_t
*)malloc(((new_n_buckets) < 16? 1 : (new_n_buckets)>>
4) * sizeof(khint32_t)); if (!new_flags) return -1; memset(new_flags
, 0xaa, ((new_n_buckets) < 16? 1 : (new_n_buckets)>>
4) * sizeof(khint32_t)); if (h->n_buckets < new_n_buckets
) { khint32_t *new_keys = (khint32_t*)realloc((void *)h->keys
,new_n_buckets * sizeof(khint32_t)); if (!new_keys) { free(new_flags
); return -1; } h->keys = new_keys; if (1) { int *new_vals
 = (int*)realloc((void *)h->vals,new_n_buckets * sizeof(int
)); if (!new_vals) { free(new_flags); return -1; } h->vals
 = new_vals; } } } } if (j) { for (j = 0; j != h->n_buckets
; ++j) { if (((h->flags[j>>4]>>((j&0xfU)<<
1))&3) == 0) { khint32_t key = h->keys[j]; int val; khint_t
 new_mask; new_mask = new_n_buckets - 1; if (1) val = h->vals
[j]; (h->flags[j>>4]|=1ul<<((j&0xfU)<<
1)); while (1) { khint_t k, i, step = 0; k = (khint32_t)(key)
; i = k & new_mask; while (!((new_flags[i>>4]>>
((i&0xfU)<<1))&2)) i = (i + (++step)) & new_mask
; (new_flags[i>>4]&=~(2ul<<((i&0xfU)<<
1))); if (i < h->n_buckets && ((h->flags[i>>
4]>>((i&0xfU)<<1))&3) == 0) { { khint32_t
 tmp = h->keys[i]; h->keys[i] = key; key = tmp; } if (1
) { int tmp = h->vals[i]; h->vals[i] = val; val = tmp; }
 (h->flags[i>>4]|=1ul<<((i&0xfU)<<1)
); } else { h->keys[i] = key; if (1) h->vals[i] = val; break
; } } } } if (h->n_buckets > new_n_buckets) { h->keys
 = (khint32_t*)realloc((void *)h->keys,new_n_buckets * sizeof
(khint32_t)); if (1) h->vals = (int*)realloc((void *)h->
vals,new_n_buckets * sizeof(int)); } free(h->flags); h->
flags = new_flags; h->n_buckets = new_n_buckets; h->n_occupied
 = h->size; h->upper_bound = (khint_t)(h->n_buckets *
 __ac_HASH_UPPER + 0.5); } return 0; } static inline __attribute__
 ((__unused__)) khint_t kh_put_ccv_cnnp_tensor_symbol_map(kh_ccv_cnnp_tensor_symbol_map_t
 *h, khint32_t key, int *ret) { khint_t x; if (h->n_occupied
 >= h->upper_bound) { if (h->n_buckets > (h->size
<<1)) { if (kh_resize_ccv_cnnp_tensor_symbol_map(h, h->
n_buckets - 1) < 0) { *ret = -1; return h->n_buckets; }
 } else if (kh_resize_ccv_cnnp_tensor_symbol_map(h, h->n_buckets
 + 1) < 0) { *ret = -1; return h->n_buckets; } } { khint_t
 k, i, site, last, mask = h->n_buckets - 1, step = 0; x = site
 = h->n_buckets; k = (khint32_t)(key); i = k & mask; if
 (((h->flags[i>>4]>>((i&0xfU)<<1))&
2)) x = i; else { last = i; while (!((h->flags[i>>4]
>>((i&0xfU)<<1))&2) && (((h->flags
[i>>4]>>((i&0xfU)<<1))&1) || !((h->
keys[i]) == (key)))) { if (((h->flags[i>>4]>>(
(i&0xfU)<<1))&1)) site = i; i = (i + (++step)) &
 mask; if (i == last) { x = site; break; } } if (x == h->n_buckets
) { if (((h->flags[i>>4]>>((i&0xfU)<<
1))&2) && site != h->n_buckets) x = site; else
 x = i; } } } if (((h->flags[x>>4]>>((x&0xfU
)<<1))&2)) { h->keys[x] = key; (h->flags[x>>
4]&=~(3ul<<((x&0xfU)<<1))); ++h->size;
 ++h->n_occupied; *ret = 1; } else if (((h->flags[x>>
4]>>((x&0xfU)<<1))&1)) { h->keys[x] = key
; (h->flags[x>>4]&=~(3ul<<((x&0xfU)<<
1))); ++h->size; *ret = 2; } else *ret = 0; return x; } static
 inline __attribute__ ((__unused__)) void kh_del_ccv_cnnp_tensor_symbol_map
(kh_ccv_cnnp_tensor_symbol_map_t *h, khint_t x) { if (x != h->
n_buckets && !((h->flags[x>>4]>>((x&
0xfU)<<1))&3)) { (h->flags[x>>4]|=1ul<<
((x&0xfU)<<1)); --h->size; } }
75KHASH_SET_INIT_INT(ccv_cnnp_tensor_symbol_set)typedef struct kh_ccv_cnnp_tensor_symbol_set_s { khint_t n_buckets
, size, n_occupied, upper_bound; khint32_t *flags; khint32_t *
keys; char *vals; } kh_ccv_cnnp_tensor_symbol_set_t; static inline
 __attribute__ ((__unused__)) kh_ccv_cnnp_tensor_symbol_set_t
 *kh_init_ccv_cnnp_tensor_symbol_set(void) { return (kh_ccv_cnnp_tensor_symbol_set_t
*)calloc(1,sizeof(kh_ccv_cnnp_tensor_symbol_set_t)); } static
 inline __attribute__ ((__unused__)) void kh_destroy_ccv_cnnp_tensor_symbol_set
(kh_ccv_cnnp_tensor_symbol_set_t *h) { if (h) { free((void *)
h->keys); free(h->flags); free((void *)h->vals); free
(h); } } static inline __attribute__ ((__unused__)) void kh_clear_ccv_cnnp_tensor_symbol_set
(kh_ccv_cnnp_tensor_symbol_set_t *h) { if (h && h->
flags) { memset(h->flags, 0xaa, ((h->n_buckets) < 16
? 1 : (h->n_buckets)>>4) * sizeof(khint32_t)); h->
size = h->n_occupied = 0; } } static inline __attribute__ (
(__unused__)) khint_t kh_get_ccv_cnnp_tensor_symbol_set(const
 kh_ccv_cnnp_tensor_symbol_set_t *h, khint32_t key) { if (h->
n_buckets) { khint_t k, i, last, mask, step = 0; mask = h->
n_buckets - 1; k = (khint32_t)(key); i = k & mask; last =
 i; while (!((h->flags[i>>4]>>((i&0xfU)<<
1))&2) && (((h->flags[i>>4]>>((i&
0xfU)<<1))&1) || !((h->keys[i]) == (key)))) { i =
 (i + (++step)) & mask; if (i == last) return h->n_buckets
; } return ((h->flags[i>>4]>>((i&0xfU)<<
1))&3)? h->n_buckets : i; } else return 0; } static inline
 __attribute__ ((__unused__)) int kh_resize_ccv_cnnp_tensor_symbol_set
(kh_ccv_cnnp_tensor_symbol_set_t *h, khint_t new_n_buckets) {
 khint32_t *new_flags = 0; khint_t j = 1; { (--(new_n_buckets
), (new_n_buckets)|=(new_n_buckets)>>1, (new_n_buckets)
|=(new_n_buckets)>>2, (new_n_buckets)|=(new_n_buckets)>>
4, (new_n_buckets)|=(new_n_buckets)>>8, (new_n_buckets)
|=(new_n_buckets)>>16, ++(new_n_buckets)); if (new_n_buckets
 < 4) new_n_buckets = 4; if (h->size >= (khint_t)(new_n_buckets
 * __ac_HASH_UPPER + 0.5)) j = 0; else { new_flags = (khint32_t
*)malloc(((new_n_buckets) < 16? 1 : (new_n_buckets)>>
4) * sizeof(khint32_t)); if (!new_flags) return -1; memset(new_flags
, 0xaa, ((new_n_buckets) < 16? 1 : (new_n_buckets)>>
4) * sizeof(khint32_t)); if (h->n_buckets < new_n_buckets
) { khint32_t *new_keys = (khint32_t*)realloc((void *)h->keys
,new_n_buckets * sizeof(khint32_t)); if (!new_keys) { free(new_flags
); return -1; } h->keys = new_keys; if (0) { char *new_vals
 = (char*)realloc((void *)h->vals,new_n_buckets * sizeof(char
)); if (!new_vals) { free(new_flags); return -1; } h->vals
 = new_vals; } } } } if (j) { for (j = 0; j != h->n_buckets
; ++j) { if (((h->flags[j>>4]>>((j&0xfU)<<
1))&3) == 0) { khint32_t key = h->keys[j]; char val; khint_t
 new_mask; new_mask = new_n_buckets - 1; if (0) val = h->vals
[j]; (h->flags[j>>4]|=1ul<<((j&0xfU)<<
1)); while (1) { khint_t k, i, step = 0; k = (khint32_t)(key)
; i = k & new_mask; while (!((new_flags[i>>4]>>
((i&0xfU)<<1))&2)) i = (i + (++step)) & new_mask
; (new_flags[i>>4]&=~(2ul<<((i&0xfU)<<
1))); if (i < h->n_buckets && ((h->flags[i>>
4]>>((i&0xfU)<<1))&3) == 0) { { khint32_t
 tmp = h->keys[i]; h->keys[i] = key; key = tmp; } if (0
) { char tmp = h->vals[i]; h->vals[i] = val; val = tmp;
 } (h->flags[i>>4]|=1ul<<((i&0xfU)<<
1)); } else { h->keys[i] = key; if (0) h->vals[i] = val
; break; } } } } if (h->n_buckets > new_n_buckets) { h->
keys = (khint32_t*)realloc((void *)h->keys,new_n_buckets *
 sizeof(khint32_t)); if (0) h->vals = (char*)realloc((void
 *)h->vals,new_n_buckets * sizeof(char)); } free(h->flags
); h->flags = new_flags; h->n_buckets = new_n_buckets; h
->n_occupied = h->size; h->upper_bound = (khint_t)(h
->n_buckets * __ac_HASH_UPPER + 0.5); } return 0; } static
 inline __attribute__ ((__unused__)) khint_t kh_put_ccv_cnnp_tensor_symbol_set
(kh_ccv_cnnp_tensor_symbol_set_t *h, khint32_t key, int *ret)
 { khint_t x; if (h->n_occupied >= h->upper_bound) {
 if (h->n_buckets > (h->size<<1)) { if (kh_resize_ccv_cnnp_tensor_symbol_set
(h, h->n_buckets - 1) < 0) { *ret = -1; return h->n_buckets
; } } else if (kh_resize_ccv_cnnp_tensor_symbol_set(h, h->
n_buckets + 1) < 0) { *ret = -1; return h->n_buckets; }
 } { khint_t k, i, site, last, mask = h->n_buckets - 1, step
 = 0; x = site = h->n_buckets; k = (khint32_t)(key); i = k
 & mask; if (((h->flags[i>>4]>>((i&0xfU
)<<1))&2)) x = i; else { last = i; while (!((h->
flags[i>>4]>>((i&0xfU)<<1))&2) &&
 (((h->flags[i>>4]>>((i&0xfU)<<1))&
1) || !((h->keys[i]) == (key)))) { if (((h->flags[i>>
4]>>((i&0xfU)<<1))&1)) site = i; i = (i +
 (++step)) & mask; if (i == last) { x = site; break; } } if
 (x == h->n_buckets) { if (((h->flags[i>>4]>>
((i&0xfU)<<1))&2) && site != h->n_buckets
) x = site; else x = i; } } } if (((h->flags[x>>4]>>
((x&0xfU)<<1))&2)) { h->keys[x] = key; (h->
flags[x>>4]&=~(3ul<<((x&0xfU)<<1)))
; ++h->size; ++h->n_occupied; *ret = 1; } else if (((h->
flags[x>>4]>>((x&0xfU)<<1))&1)) { h
->keys[x] = key; (h->flags[x>>4]&=~(3ul<<
((x&0xfU)<<1))); ++h->size; *ret = 2; } else *ret
 = 0; return x; } static inline __attribute__ ((__unused__)) void
 kh_del_ccv_cnnp_tensor_symbol_set(kh_ccv_cnnp_tensor_symbol_set_t
 *h, khint_t x) { if (x != h->n_buckets && !((h->
flags[x>>4]>>((x&0xfU)<<1))&3)) { (
h->flags[x>>4]|=1ul<<((x&0xfU)<<1));
 --h->size; } }
11
←
Taking true branch→
12
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Taking false branch→
13
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Calling 'kh_resize_ccv_cnnp_tensor_symbol_set'→
14
←
Taking true branch→
15
←
Assuming the condition is false→
16
←
Taking false branch→
17
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'?' condition is true→
18
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Assuming 'new_flags' is non-null→
19
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Taking false branch→
20
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'?' condition is true→
21
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Taking true branch→
22
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Storing uninitialized value→
23
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Assuming 'new_keys' is non-null→
24
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Taking false branch→
25
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Taking false branch→
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Assuming field 'n_occupied' is >= field 'upper_bound'→
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Calling 'kh_resize_ccv_cnnp_tensor_symbol_set'→
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59
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Assigned value is garbage or undefined
76 
77void ccv_cnnp_model_apply_gradient_checkpoints(ccv_cnnp_compiled_data_t* const compiled_data, ccv_nnc_symbolic_graph_t* const graph)
78{
79	ccv_array_t* const gradient_checkpoints = compiled_data->gradient_checkpoints;
80	if (!gradient_checkpoints || gradient_checkpoints->rnum == 0) // No saved gradient checkpoints, this is an easy way out.
1
Assuming 'gradient_checkpoints' is non-null→
2
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Assuming field 'rnum' is not equal to 0→
3
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Taking false branch→
81		return;
82	// Otherwise, for each gradient checkpoint, there are 3 steps:
83	// 1. Find currently, what execs exists from inputs to outputs.
84	// 2. Find execs that generates the outputs, and their corresponding backward execs.
85	// 3. Find all backward execs flow from outputs back to inputs.
86	// 4. Generate new ops by calling build again with old inputs, record all new tensors / execs.
87	// 5. Replace inputs in backward execs with the new tensors.
88	// 6. Hook the execs takes inputs with edge from parents of backward execs in step 2.
89	// 7. Delete newly generated execs that has no use (i.e. its outputs are not used by backward pass).
90	// 8. Mark all new execs with DISABLE_OPT to avoid common sub-expression elimination pass.
91	int i, j, k, l;
92	ccv_array_t* input_execs = ccv_array_new(sizeof(ccv_nnc_graph_exec_symbol_t), 0, 0);
93	ccv_array_t* output_execs = ccv_array_new(sizeof(ccv_nnc_graph_exec_symbol_t), 0, 0);
94	ccv_array_t* input_gradient_execs = ccv_array_new(sizeof(ccv_nnc_graph_exec_symbol_t), 0, 0);
95	ccv_array_t* output_gradient_execs = ccv_array_new(sizeof(ccv_nnc_graph_exec_symbol_t), 0, 0);
96	ccv_array_t* visited_backward_execs = ccv_array_new(sizeof(int), 0, 0);
97	ccv_array_t* replaced_backward_execs = ccv_array_new(sizeof(int), 0, 0);
98	const int exec_rnum = graph->exec_symbol_info->rnum;
99	ccv_nnc_graph_exec_symbol_reverse_t* const reversed_nodes = cccalloccalloc(exec_rnum, sizeof(ccv_nnc_graph_exec_symbol_reverse_t));
100	for (i = 0; i < exec_rnum; i++)
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101	{
102		const int* tos = 0;
103		int to_size = 0;
104		ccv_nnc_graph_exec_symbol_to(graph, (ccv_nnc_graph_exec_symbol_t){
105			.graph = graph,
106			.d = i
107		}, &tos, &to_size);
108		if (tos)
109			for (j = 0; j < to_size; j++)
110			{
111				if (!reversed_nodes[tos[j]].outgoings)
112					reversed_nodes[tos[j]].outgoings = ccv_array_new(sizeof(int), 1, 0);
113				ccv_array_add_unique_int(reversed_nodes[tos[j]].outgoings, i);
114			}
115	}
116	uint32_t* const maskbit = cccalloccalloc((exec_rnum + 31) >> 5, sizeof(uint32_t));
117	// Temporary for build_data.
118	ccv_array_t* const parameters = ccv_array_new(sizeof(ccv_nnc_tensor_symbol_t), 0, 0);
119	ccv_array_t* const parameter_ids = ccv_array_new(sizeof(char*), 0, 0);
120	ccv_array_t* const parameter_trainables = ccv_array_new(sizeof(int), 0, 0);
121	ccv_array_t* const internals = ccv_array_new(sizeof(ccv_nnc_tensor_symbol_t), 0, 0);
122	ccv_array_t* const internal_ids = ccv_array_new(sizeof(char*), 0, 0);
123	ccv_array_t* const buf = ccv_array_new(sizeof(int), 0, 0);
124	int max_output_size = 0;
125	for (i = 0; i < gradient_checkpoints->rnum; i++)
6
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Loop condition is false. Execution continues on line 130→
126	{
127		ccv_cnnp_model_gradient_checkpoint_t* const checkpoint = (ccv_cnnp_model_gradient_checkpoint_t*)ccv_array_get(gradient_checkpoints, i)((void*)(((char*)((gradient_checkpoints)->data)) + (size_t
)(gradient_checkpoints)->rsize * (size_t)(i)));
128		max_output_size = ccv_max(checkpoint->output_size, max_output_size)({ typeof (checkpoint->output_size) _a = (checkpoint->output_size
); typeof (max_output_size) _b = (max_output_size); (_a > _b
) ? _a : _b; });
129	}
130	ccv_nnc_tensor_symbol_t* max_outputs = ccmallocmalloc(sizeof(ccv_nnc_tensor_symbol_t) * max_output_size);
131	ccv_array_t* newly_used_outputs = ccv_array_new(sizeof(int), 0, 0);
132	khash_t(ccv_cnnp_tensor_symbol_set)kh_ccv_cnnp_tensor_symbol_set_t* const parameters_or_internals = kh_init(ccv_cnnp_tensor_symbol_set)kh_init_ccv_cnnp_tensor_symbol_set();
133	for (i = 0; i < compiled_data->parameters->rnum; i++)
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Loop condition is true.  Entering loop body→
39
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Assuming 'i' is < field 'rnum'→
40
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Loop condition is true.  Entering loop body→
134	{
135		const ccv_nnc_tensor_symbol_t* const symbol = (const ccv_nnc_tensor_symbol_t*)ccv_array_get(compiled_data->parameters, i)((void*)(((char*)((compiled_data->parameters)->data)) +
 (size_t)(compiled_data->parameters)->rsize * (size_t)(
i)));
136		int ret;
137		kh_put(ccv_cnnp_tensor_symbol_set, parameters_or_internals, symbol->d, &ret)kh_put_ccv_cnnp_tensor_symbol_set(parameters_or_internals, symbol
->d, &ret);
10
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Calling 'kh_put_ccv_cnnp_tensor_symbol_set'→
38
←
Returning from 'kh_put_ccv_cnnp_tensor_symbol_set'→
41
←
Calling 'kh_put_ccv_cnnp_tensor_symbol_set'→
138	}
139	for (i = 0; i < compiled_data->internals->rnum; i++)
140	{
141		const ccv_nnc_tensor_symbol_t* const symbol = (const ccv_nnc_tensor_symbol_t*)ccv_array_get(compiled_data->parameters, i)((void*)(((char*)((compiled_data->parameters)->data)) +
 (size_t)(compiled_data->parameters)->rsize * (size_t)(
i)));
142		int ret;
143		kh_put(ccv_cnnp_tensor_symbol_set, parameters_or_internals, symbol->d, &ret)kh_put_ccv_cnnp_tensor_symbol_set(parameters_or_internals, symbol
->d, &ret);
144	}
145	khash_t(ccv_cnnp_tensor_symbol_set)kh_ccv_cnnp_tensor_symbol_set_t* const newly_created_tensor_symbols = kh_init(ccv_cnnp_tensor_symbol_set)kh_init_ccv_cnnp_tensor_symbol_set();
146	khash_t(ccv_cnnp_tensor_symbol_map)kh_ccv_cnnp_tensor_symbol_map_t* symbol_map = kh_init(ccv_cnnp_tensor_symbol_map)kh_init_ccv_cnnp_tensor_symbol_map();
147	for (i = 0; i < gradient_checkpoints->rnum; i++)
148	{
149		ccv_cnnp_model_gradient_checkpoint_t* const checkpoint = (ccv_cnnp_model_gradient_checkpoint_t*)ccv_array_get(gradient_checkpoints, i)((void*)(((char*)((gradient_checkpoints)->data)) + (size_t
)(gradient_checkpoints)->rsize * (size_t)(i)));
150		kh_clear(ccv_cnnp_tensor_symbol_set, newly_created_tensor_symbols)kh_clear_ccv_cnnp_tensor_symbol_set(newly_created_tensor_symbols
);
151		for (j = 0; j < checkpoint->tensor_symbols->rnum; j++)
152		{
153			const int idx = ((ccv_nnc_tensor_symbol_t*)ccv_array_get(checkpoint->tensor_symbols, j)((void*)(((char*)((checkpoint->tensor_symbols)->data)) +
 (size_t)(checkpoint->tensor_symbols)->rsize * (size_t)
(j))))->d;
154			if (idx < 0)
155				continue;
156			// Skip parameters or internals.
157			if (kh_get(ccv_cnnp_tensor_symbol_set, parameters_or_internals, idx)kh_get_ccv_cnnp_tensor_symbol_set(parameters_or_internals, idx
) != kh_end(parameters_or_internals)((parameters_or_internals)->n_buckets))
158				continue;
159			int ret;
160			kh_put(ccv_cnnp_tensor_symbol_set, newly_created_tensor_symbols, idx, &ret)kh_put_ccv_cnnp_tensor_symbol_set(newly_created_tensor_symbols
, idx, &ret);
161		}
162		ccv_array_clear(input_execs);
163		ccv_array_clear(output_execs);
164		ccv_nnc_graph_exec_symbol_info_t* exec_info = (ccv_nnc_graph_exec_symbol_info_t*)ccv_array_get(graph->exec_symbol_info, 0)((void*)(((char*)((graph->exec_symbol_info)->data)) + (
size_t)(graph->exec_symbol_info)->rsize * (size_t)(0)));
165		for (j = 0; j < exec_rnum; j++)
166		{
167			if (CCV_NNC_GRAPH_EXEC_IS_DEAD(exec_info[j].flags)((exec_info[j].flags) & CCV_NNC_GRAPH_EXEC_DEAD))
168				continue;
169			const int* inputs = exec_info[j].inputs;
170			int input_size = exec_info[j].input_size;
171			const int* outputs = exec_info[j].outputs;
172			int output_size = exec_info[j].output_size;
173			if (input_size == 0 && output_size == 0)
174				continue;
175			// Only go through forward pass.
176			if (ccv_nnc_cmd_is_backward(exec_info[j].cmd))
177				continue;
178			const ccv_nnc_graph_exec_symbol_t symbol = {
179				.graph = graph,
180				.d = j
181			};
182			int flag = 0;
183			for (k = 0; inputs && k < input_size && !flag; k++)
184				if (inputs[k] >= 0)
185					for (l = 0; l < checkpoint->input_size && !flag; l++)
186						if (checkpoint->inputs[l].d >= 0 && inputs[k] == checkpoint->inputs[l].d)
187							flag = 1;
188			// Input logic is different from output logic. We need to filter out these exec that contains inputs from within the graph.
189			for (k = 0; inputs && k < input_size && flag; k++)
190				if (inputs[k] >= 0 && kh_get(ccv_cnnp_tensor_symbol_set, newly_created_tensor_symbols, inputs[k])kh_get_ccv_cnnp_tensor_symbol_set(newly_created_tensor_symbols
, inputs[k]) != kh_end(newly_created_tensor_symbols)((newly_created_tensor_symbols)->n_buckets))
191					flag = 0;
192			if (flag)
193				ccv_array_push(input_execs, &symbol);
194			flag = 0;
195			for (k = 0; outputs && k < output_size && !flag; k++)
196				if (outputs[k] >= 0)
197					for (l = 0; l < checkpoint->output_size && !flag; l++)
198						if (checkpoint->outputs[l].d >= 0 && outputs[k] == checkpoint->outputs[l].d)
199							flag = 1;
200			if (flag)
201				ccv_array_push(output_execs, &symbol);
202		}
203		if (input_execs->rnum <= 0 || output_execs->rnum <= 0)
204			continue;
205		// Fill in blanks (i.e. the backward ops that are not showing in above, but should be included to avoid excluding necessary ones). This is done by flowing gradients from outputs back all the way to inputs.
206		ccv_array_clear(input_gradient_execs);
207		ccv_array_clear(output_gradient_execs);
208		for (j = 0; j < input_execs->rnum; j++)
209		{
210			const int d = ((ccv_nnc_graph_exec_symbol_t*)ccv_array_get(input_execs, j)((void*)(((char*)((input_execs)->data)) + (size_t)(input_execs
)->rsize * (size_t)(j))))->d;
211			for (k = 0; k < exec_info[d].input_size; k++)
212				if (exec_info[d].inputs[k] >= 0)
213				{
214					const ccv_nnc_tensor_symbol_t gradient_symbol = ccv_nnc_tensor_symbol_for_backward(graph, (ccv_nnc_tensor_symbol_t){
215						.graph = graph,
216						.d = exec_info[d].inputs[k]
217					});
218					if (gradient_symbol.d < 0)
219						continue;
220					const ccv_nnc_graph_exec_symbol_t backward = ccv_nnc_graph_exec_symbol_for_backward(graph, gradient_symbol);
221					if (backward.d < 0)
222						continue;
223					if (CCV_NNC_GRAPH_EXEC_IS_DEAD(exec_info[backward.d].flags)((exec_info[backward.d].flags) & CCV_NNC_GRAPH_EXEC_DEAD))
224						continue;
225					int flag = 0;
226					for (l = 0; !flag && l < output_gradient_execs->rnum; l++)
227						if (((ccv_nnc_graph_exec_symbol_t*)ccv_array_get(output_gradient_execs, l)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(l))))->d == backward.d)
228							flag = 1;
229					if (!flag)
230						ccv_array_push(output_gradient_execs, &backward);
231				}
232			if (exec_info[d].outgoings && exec_info[d].outgoings->rnum > 0)
233				for (k = 0; k < exec_info[d].outgoings->rnum; k++)
234				{
235					const int to_d = *(int*)ccv_array_get(exec_info[d].outgoings, k)((void*)(((char*)((exec_info[d].outgoings)->data)) + (size_t
)(exec_info[d].outgoings)->rsize * (size_t)(k)));
236					if (!ccv_nnc_cmd_is_backward(exec_info[to_d].cmd))
237						continue;
238					int flag = 0;
239					for (l = 0; !flag && l < output_gradient_execs->rnum; l++)
240						if (((ccv_nnc_graph_exec_symbol_t*)ccv_array_get(output_gradient_execs, l)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(l))))->d == to_d)
241							flag = 1;
242					if (!flag)
243					{
244						const ccv_nnc_graph_exec_symbol_t backward = {
245							.graph = graph,
246							.d = to_d
247						};
248						ccv_array_push(output_gradient_execs, &backward);
249					}
250				}
251		}
252		// For output_gradient_execs, we can be opportunistic and use the wrt symbols (if exists) to find relevant bits.
253		// For input_gradient_execs, there is no other way but to loop over all outgoings, find the ones are direct link as backward execs.
254		for (j = 0; j < output_execs->rnum; j++)
255		{
256			const int d = ((ccv_nnc_graph_exec_symbol_t*)ccv_array_get(output_execs, j)((void*)(((char*)((output_execs)->data)) + (size_t)(output_execs
)->rsize * (size_t)(j))))->d;
257			if (exec_info[d].outgoings && exec_info[d].outgoings->rnum > 0)
258				for (k = 0; k < exec_info[d].outgoings->rnum; k++)
259				{
260					const int to_d = *(int*)ccv_array_get(exec_info[d].outgoings, k)((void*)(((char*)((exec_info[d].outgoings)->data)) + (size_t
)(exec_info[d].outgoings)->rsize * (size_t)(k)));
261					if (!ccv_nnc_cmd_is_backward(exec_info[to_d].cmd))
262						continue;
263					int flag = 0;
264					for (l = 0; !flag && l < input_gradient_execs->rnum; l++)
265						if (((ccv_nnc_graph_exec_symbol_t*)ccv_array_get(input_gradient_execs, l)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(l))))->d == to_d)
266							flag = 1;
267					if (!flag)
268					{
269						const ccv_nnc_graph_exec_symbol_t backward = {
270							.graph = graph,
271							.d = to_d
272						};
273						ccv_array_push(input_gradient_execs, &backward);
274					}
275				}
276		}
277		// Note that we have to use up-to-date ones because the exec_info might have outgoings that is up-to-date.
278		ccv_nnc_graph_visit_t* const visit = ccv_nnc_graph_visit_new(graph, exec_info, graph->exec_symbol_info->rnum, (ccv_nnc_graph_exec_symbol_t*)ccv_array_get(input_gradient_execs, 0), input_gradient_execs->rnum, (ccv_nnc_graph_exec_symbol_t*)ccv_array_get(output_gradient_execs, 0), output_gradient_execs->rnum, 1)({ ccv_nnc_graph_visit_t* _visit_ = (ccv_nnc_graph_visit_t*)malloc
(sizeof(ccv_nnc_graph_visit_t) + sizeof(_visit_->node[0]) *
 ((graph->exec_symbol_info->rnum) - 1)); _visit_->size
 = 0; do { typedef struct { int8_t d; int8_t r; uint16_t c; int32_t
 edges; } ccv_nnc_incoming_t; int _i_, _j_; int _incoming_edges_
 = 0; for (_i_ = 0; _i_ < (graph->exec_symbol_info->
rnum); _i_++) _incoming_edges_ += ((exec_info)[_i_].outgoings
) ? (exec_info)[_i_].outgoings->rnum : 0; const int _heap_mem_
 = ((graph->exec_symbol_info->rnum) + _incoming_edges_ >
 1024); ccv_nnc_incoming_t* _incomings_; if (_heap_mem_) _incomings_
 = (ccv_nnc_incoming_t*)malloc(sizeof(ccv_nnc_incoming_t) * (
graph->exec_symbol_info->rnum) + sizeof(int32_t) * ((graph
->exec_symbol_info->rnum) * 2 + _incoming_edges_)); else
 _incomings_ = (ccv_nnc_incoming_t*)__builtin_alloca (sizeof(
ccv_nnc_incoming_t) * (graph->exec_symbol_info->rnum) +
 sizeof(int32_t) * ((graph->exec_symbol_info->rnum) * 2
 + _incoming_edges_)); memset(_incomings_, 0, sizeof(ccv_nnc_incoming_t
) * (graph->exec_symbol_info->rnum)); int32_t* _exists_
[2] = { (int32_t*)(_incomings_ + (graph->exec_symbol_info->
rnum)), (int32_t*)(_incomings_ + (graph->exec_symbol_info->
rnum)) + (graph->exec_symbol_info->rnum), }; int32_t* const
 _edges_ = _exists_[1] + (graph->exec_symbol_info->rnum
); for (_i_ = 0; _i_ < (input_gradient_execs->rnum); _i_
++) { ((void) sizeof ((((ccv_nnc_graph_exec_symbol_t*)((void*
)(((char*)((input_gradient_execs)->data)) + (size_t)(input_gradient_execs
)->rsize * (size_t)(0))))[_i_].graph == graph) ? 1 : 0), __extension__
 ({ if (((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((input_gradient_execs
)->data)) + (size_t)(input_gradient_execs)->rsize * (size_t
)(0))))[_i_].graph == graph) ; else __assert_fail ("((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].graph == graph"
, "ccv_cnnp_model_gradient_checkpointing.c", 278, __extension__
 __PRETTY_FUNCTION__); })); _incomings_[((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].d].r =
 1; _exists_[0][_i_] = ((ccv_nnc_graph_exec_symbol_t*)((void*
)(((char*)((input_gradient_execs)->data)) + (size_t)(input_gradient_execs
)->rsize * (size_t)(0))))[_i_].d; } int _exist_size_[2] = {
 (input_gradient_execs->rnum), 0, }; int _p_ = 0, _q_ = 1;
 while (_exist_size_[_p_] > 0) { _exist_size_[_q_] = 0; for
 (_i_ = 0; _i_ < _exist_size_[_p_]; _i_++) { const int32_t
 _idx_ = _exists_[_p_][_i_]; if (_incomings_[_idx_].r != 1) continue
; _incomings_[_idx_].r = 2; if ((exec_info)[_idx_].outgoings)
 for (_j_ = 0; _j_ < (exec_info)[_idx_].outgoings->rnum
; _j_++) { const int d = *(int*)((void*)(((char*)(((exec_info
)[_idx_].outgoings)->data)) + (size_t)((exec_info)[_idx_].
outgoings)->rsize * (size_t)(_j_))); ++_incomings_[d].c; if
 (_incomings_[d].r != 0) continue; _incomings_[d].r = 1; ((void
) sizeof ((_exist_size_[_q_] < (graph->exec_symbol_info
->rnum)) ? 1 : 0), __extension__ ({ if (_exist_size_[_q_] <
 (graph->exec_symbol_info->rnum)) ; else __assert_fail (
"_exist_size_[_q_] < (graph->exec_symbol_info->rnum)"
, "ccv_cnnp_model_gradient_checkpointing.c", 278, __extension__
 __PRETTY_FUNCTION__); })); _exists_[_q_][_exist_size_[_q_]] =
 d; ++_exist_size_[_q_]; } } ((_i_) = (_p_), (_p_) = (_q_), (
_q_) = (_i_)); } for (_i_ = 0; _i_ < (input_gradient_execs
->rnum); _i_++) { ((void) sizeof ((((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ? 1 : 0), __extension__ ({ if (((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ; else __assert_fail ("((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].graph == graph"
, "ccv_cnnp_model_gradient_checkpointing.c", 278, __extension__
 __PRETTY_FUNCTION__); })); _incomings_[((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].d].r =
 3; _exists_[0][_i_] = ((ccv_nnc_graph_exec_symbol_t*)((void*
)(((char*)((input_gradient_execs)->data)) + (size_t)(input_gradient_execs
)->rsize * (size_t)(0))))[_i_].d; } _exist_size_[0] = (input_gradient_execs
->rnum); _exist_size_[1] = 0; _p_ = 0, _q_ = 1; int _bump_
 = 1; while (_exist_size_[_p_] > 0) { _exist_size_[_q_] = 0
; for (_i_ = 0; _i_ < _exist_size_[_p_]; _i_++) { const int32_t
 _idx_ = _exists_[_p_][_i_]; if (_incomings_[_idx_].r != 3) continue
; _incomings_[_idx_].r = 4; if ((exec_info)[_idx_].outgoings)
 for (_j_ = 0; _j_ < (exec_info)[_idx_].outgoings->rnum
; _j_++) { const int d = *(int*)((void*)(((char*)(((exec_info
)[_idx_].outgoings)->data)) + (size_t)((exec_info)[_idx_].
outgoings)->rsize * (size_t)(_j_))); if (_incomings_[d].edges
 == 0) { _incomings_[d].edges = _bump_; _bump_ += _incomings_
[d].c; _incomings_[d].c = 0; } _edges_[_incomings_[d].edges -
 1 + _incomings_[d].c] = _idx_; ++_incomings_[d].c; if (_incomings_
[d].r != 2) continue; _incomings_[d].r = 3; ((void) sizeof ((
_exist_size_[_q_] < (graph->exec_symbol_info->rnum))
 ? 1 : 0), __extension__ ({ if (_exist_size_[_q_] < (graph
->exec_symbol_info->rnum)) ; else __assert_fail ("_exist_size_[_q_] < (graph->exec_symbol_info->rnum)"
, "ccv_cnnp_model_gradient_checkpointing.c", 278, __extension__
 __PRETTY_FUNCTION__); })); _exists_[_q_][_exist_size_[_q_]] =
 d; ++_exist_size_[_q_]; } } ((_i_) = (_p_), (_p_) = (_q_), (
_q_) = (_i_)); } for (_i_ = 0; _i_ < (output_gradient_execs
->rnum); _i_++) { ((void) sizeof ((((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ? 1 : 0), __extension__ ({ if (((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ; else __assert_fail ("((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].graph == graph"
, "ccv_cnnp_model_gradient_checkpointing.c", 278, __extension__
 __PRETTY_FUNCTION__); })); _incomings_[((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].d].r
 = 5; _exists_[0][_i_] = ((ccv_nnc_graph_exec_symbol_t*)((void
*)(((char*)((output_gradient_execs)->data)) + (size_t)(output_gradient_execs
)->rsize * (size_t)(0))))[_i_].d; } _exist_size_[0] = (output_gradient_execs
->rnum); _exist_size_[1] = 0; _p_ = 0, _q_ = 1; while (_exist_size_
[_p_] > 0) { _exist_size_[_q_] = 0; for (_i_ = 0; _i_ <
 _exist_size_[_p_]; _i_++) { const int32_t _idx_ = _exists_[_p_
][_i_]; if (_incomings_[_idx_].r != 5) continue; _incomings_[
_idx_].r = 6; if (_incomings_[_idx_].edges > 0) for (_j_ =
 0; _j_ < _incomings_[_idx_].c; _j_++) { const int d = _edges_
[_incomings_[_idx_].edges - 1 + _j_]; if (_incomings_[d].r !=
 4) continue; _incomings_[d].r = 5; ((void) sizeof ((_exist_size_
[_q_] < (graph->exec_symbol_info->rnum)) ? 1 : 0), __extension__
 ({ if (_exist_size_[_q_] < (graph->exec_symbol_info->
rnum)) ; else __assert_fail ("_exist_size_[_q_] < (graph->exec_symbol_info->rnum)"
, "ccv_cnnp_model_gradient_checkpointing.c", 278, __extension__
 __PRETTY_FUNCTION__); })); _exists_[_q_][_exist_size_[_q_]] =
 d; ++_exist_size_[_q_]; } } ((_i_) = (_p_), (_p_) = (_q_), (
_q_) = (_i_)); } for (_i_ = 0; _i_ < (output_gradient_execs
->rnum); _i_++) { ((void) sizeof ((((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ? 1 : 0), __extension__ ({ if (((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ; else __assert_fail ("((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].graph == graph"
, "ccv_cnnp_model_gradient_checkpointing.c", 278, __extension__
 __PRETTY_FUNCTION__); })); _incomings_[((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].d].d
 = 1; } for (_i_ = 0; _i_ < (input_gradient_execs->rnum
); _i_++) { ((void) sizeof ((((ccv_nnc_graph_exec_symbol_t*)(
(void*)(((char*)((input_gradient_execs)->data)) + (size_t)
(input_gradient_execs)->rsize * (size_t)(0))))[_i_].graph ==
 graph) ? 1 : 0), __extension__ ({ if (((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ; else __assert_fail ("((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].graph == graph"
, "ccv_cnnp_model_gradient_checkpointing.c", 278, __extension__
 __PRETTY_FUNCTION__); })); _exists_[0][_i_] = ((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].d; } _p_
 = 0; _q_ = 1; _exist_size_[0] = (input_gradient_execs->rnum
); _exist_size_[1] = 0; int _d_ = 0; while (_exist_size_[_p_]
 > 0) { _exist_size_[_q_] = 0; for (_i_ = 0; _i_ < _exist_size_
[_p_];) { const int32_t _idx_ = _exists_[_p_][_i_]; _visit_->
node[_visit_->size].index = ((_idx_)); _visit_->node[_visit_
->size].term = ((_incomings_[_idx_].d)); ++_visit_->size
;; if (_incomings_[_idx_].d) { ++_d_; _incomings_[_idx_].r = 7
; } if ((exec_info)[_idx_].outgoings) { if ((exec_info)[_idx_
].outgoings->rnum == 1) { const int d = *(int*)((void*)(((
char*)(((exec_info)[_idx_].outgoings)->data)) + (size_t)((
exec_info)[_idx_].outgoings)->rsize * (size_t)(0))); --_incomings_
[d].c; if (_incomings_[d].c == 0 && _incomings_[d].r ==
 6 && _d_ < (output_gradient_execs->rnum)) { _exists_
[_p_][_i_] = d; continue; } } else for (_j_ = 0; _j_ < (exec_info
)[_idx_].outgoings->rnum; _j_++) { const int d = *(int*)((
void*)(((char*)(((exec_info)[_idx_].outgoings)->data)) + (
size_t)((exec_info)[_idx_].outgoings)->rsize * (size_t)(_j_
))); --_incomings_[d].c; if (_incomings_[d].c == 0 &&
 _incomings_[d].r == 6 && _d_ < (output_gradient_execs
->rnum)) { ((void) sizeof ((_exist_size_[_q_] < (graph->
exec_symbol_info->rnum)) ? 1 : 0), __extension__ ({ if (_exist_size_
[_q_] < (graph->exec_symbol_info->rnum)) ; else __assert_fail
 ("_exist_size_[_q_] < (graph->exec_symbol_info->rnum)"
, "ccv_cnnp_model_gradient_checkpointing.c", 278, __extension__
 __PRETTY_FUNCTION__); })); _exists_[_q_][_exist_size_[_q_]] =
 d; ++_exist_size_[_q_]; } } } ++_i_; } ((_i_) = (_p_), (_p_)
 = (_q_), (_q_) = (_i_)); } for (_i_ = 0; _i_ < (output_gradient_execs
->rnum); _i_++) { ((void) sizeof ((((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ? 1 : 0), __extension__ ({ if (((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ; else __assert_fail ("((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].graph == graph"
, "ccv_cnnp_model_gradient_checkpointing.c", 278, __extension__
 __PRETTY_FUNCTION__); })); if (_incomings_[((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].d].r
 == 7) continue; if (!(1)) { ((void) sizeof ((_incomings_[((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].d].c
 == 0) ? 1 : 0), __extension__ ({ if (_incomings_[((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].d].c
 == 0) ; else __assert_fail ("_incomings_[((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].d].c == 0"
, "ccv_cnnp_model_gradient_checkpointing.c", 278, __extension__
 __PRETTY_FUNCTION__); })); } else if (_incomings_[((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].d].c
 > 0) continue; _visit_->node[_visit_->size].index =
 ((((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((output_gradient_execs
)->data)) + (size_t)(output_gradient_execs)->rsize * (size_t
)(0))))[_i_].d)); _visit_->node[_visit_->size].term = (
(_incomings_[((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)
((output_gradient_execs)->data)) + (size_t)(output_gradient_execs
)->rsize * (size_t)(0))))[_i_].d].d)); ++_visit_->size;
; } if (_heap_mem_) free(_incomings_); } while (0);; ((void) sizeof
 ((_visit_->size <= (graph->exec_symbol_info->rnum
)) ? 1 : 0), __extension__ ({ if (_visit_->size <= (graph
->exec_symbol_info->rnum)) ; else __assert_fail ("_visit_->size <= (graph->exec_symbol_info->rnum)"
, "ccv_cnnp_model_gradient_checkpointing.c", 278, __extension__
 __PRETTY_FUNCTION__); })); _visit_; });
279		ccv_nnc_graph_visit_for(visit, exec_info, node, idx){ int _i_; for (_i_ = 0; _i_ < (visit)->size; _i_++) { const
 int idx __attribute__((unused)) = (visit)->node[_i_].index
; const int _node_unused_ __attribute__((unused)) = (visit)->
node[_i_].term; typeof ((exec_info)) const node __attribute__
((unused)) = (exec_info) + idx; {
280			if (idx < exec_rnum && !CCV_NNC_GRAPH_EXEC_IS_DEAD(node->flags)((node->flags) & CCV_NNC_GRAPH_EXEC_DEAD))
281				maskbit[idx >> 5] |= (1u << (idx & 0x1f));
282		} ccv_nnc_graph_visit_endfor} }
283		ccv_array_clear(visited_backward_execs);
284		// Add more backward pass to the list. Note that we don't add everything, particularly there are new nodes created through gradient checkpointing are ignored.
285#define visitor(node, idx, _) \
286		if (idx < exec_rnum && !CCV_NNC_GRAPH_EXEC_IS_DEAD(exec_info[idx].flags)((exec_info[idx].flags) & CCV_NNC_GRAPH_EXEC_DEAD) && maskbit[idx >> 5] & (1u << (idx & 0x1f))) \
287			ccv_array_add_unique_int(visited_backward_execs, idx);
288		CCV_NNC_GRAPH_VISIT(graph, reversed_nodes, exec_rnum, (ccv_nnc_graph_exec_symbol_t*)ccv_array_get(output_gradient_execs, 0), output_gradient_execs->rnum, (ccv_nnc_graph_exec_symbol_t*)ccv_array_get(input_gradient_execs, 0), input_gradient_execs->rnum, 0, visitor)do { typedef struct { int8_t d; int8_t r; uint16_t c; int32_t
 edges; } ccv_nnc_incoming_t; int _i_, _j_; int _incoming_edges_
 = 0; for (_i_ = 0; _i_ < (exec_rnum); _i_++) _incoming_edges_
 += ((reversed_nodes)[_i_].outgoings) ? (reversed_nodes)[_i_]
.outgoings->rnum : 0; const int _heap_mem_ = ((exec_rnum) +
 _incoming_edges_ > 1024); ccv_nnc_incoming_t* _incomings_
; if (_heap_mem_) _incomings_ = (ccv_nnc_incoming_t*)malloc(sizeof
(ccv_nnc_incoming_t) * (exec_rnum) + sizeof(int32_t) * ((exec_rnum
) * 2 + _incoming_edges_)); else _incomings_ = (ccv_nnc_incoming_t
*)__builtin_alloca (sizeof(ccv_nnc_incoming_t) * (exec_rnum) +
 sizeof(int32_t) * ((exec_rnum) * 2 + _incoming_edges_)); memset
(_incomings_, 0, sizeof(ccv_nnc_incoming_t) * (exec_rnum)); int32_t
* _exists_[2] = { (int32_t*)(_incomings_ + (exec_rnum)), (int32_t
*)(_incomings_ + (exec_rnum)) + (exec_rnum), }; int32_t* const
 _edges_ = _exists_[1] + (exec_rnum); for (_i_ = 0; _i_ < (
output_gradient_execs->rnum); _i_++) { ((void) sizeof ((((
ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((output_gradient_execs
)->data)) + (size_t)(output_gradient_execs)->rsize * (size_t
)(0))))[_i_].graph == graph) ? 1 : 0), __extension__ ({ if ((
(ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((output_gradient_execs
)->data)) + (size_t)(output_gradient_execs)->rsize * (size_t
)(0))))[_i_].graph == graph) ; else __assert_fail ("((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].graph == graph"
, "ccv_cnnp_model_gradient_checkpointing.c", 288, __extension__
 __PRETTY_FUNCTION__); })); _incomings_[((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].d].r
 = 1; _exists_[0][_i_] = ((ccv_nnc_graph_exec_symbol_t*)((void
*)(((char*)((output_gradient_execs)->data)) + (size_t)(output_gradient_execs
)->rsize * (size_t)(0))))[_i_].d; } int _exist_size_[2] = {
 (output_gradient_execs->rnum), 0, }; int _p_ = 0, _q_ = 1
; while (_exist_size_[_p_] > 0) { _exist_size_[_q_] = 0; for
 (_i_ = 0; _i_ < _exist_size_[_p_]; _i_++) { const int32_t
 _idx_ = _exists_[_p_][_i_]; if (_incomings_[_idx_].r != 1) continue
; _incomings_[_idx_].r = 2; if ((reversed_nodes)[_idx_].outgoings
) for (_j_ = 0; _j_ < (reversed_nodes)[_idx_].outgoings->
rnum; _j_++) { const int d = *(int*)((void*)(((char*)(((reversed_nodes
)[_idx_].outgoings)->data)) + (size_t)((reversed_nodes)[_idx_
].outgoings)->rsize * (size_t)(_j_))); ++_incomings_[d].c;
 if (_incomings_[d].r != 0) continue; _incomings_[d].r = 1; (
(void) sizeof ((_exist_size_[_q_] < (exec_rnum)) ? 1 : 0),
 __extension__ ({ if (_exist_size_[_q_] < (exec_rnum)) ; else
 __assert_fail ("_exist_size_[_q_] < (exec_rnum)", "ccv_cnnp_model_gradient_checkpointing.c"
, 288, __extension__ __PRETTY_FUNCTION__); })); _exists_[_q_]
[_exist_size_[_q_]] = d; ++_exist_size_[_q_]; } } ((_i_) = (_p_
), (_p_) = (_q_), (_q_) = (_i_)); } for (_i_ = 0; _i_ < (output_gradient_execs
->rnum); _i_++) { ((void) sizeof ((((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ? 1 : 0), __extension__ ({ if (((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ; else __assert_fail ("((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].graph == graph"
, "ccv_cnnp_model_gradient_checkpointing.c", 288, __extension__
 __PRETTY_FUNCTION__); })); _incomings_[((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].d].r
 = 3; _exists_[0][_i_] = ((ccv_nnc_graph_exec_symbol_t*)((void
*)(((char*)((output_gradient_execs)->data)) + (size_t)(output_gradient_execs
)->rsize * (size_t)(0))))[_i_].d; } _exist_size_[0] = (output_gradient_execs
->rnum); _exist_size_[1] = 0; _p_ = 0, _q_ = 1; int _bump_
 = 1; while (_exist_size_[_p_] > 0) { _exist_size_[_q_] = 0
; for (_i_ = 0; _i_ < _exist_size_[_p_]; _i_++) { const int32_t
 _idx_ = _exists_[_p_][_i_]; if (_incomings_[_idx_].r != 3) continue
; _incomings_[_idx_].r = 4; if ((reversed_nodes)[_idx_].outgoings
) for (_j_ = 0; _j_ < (reversed_nodes)[_idx_].outgoings->
rnum; _j_++) { const int d = *(int*)((void*)(((char*)(((reversed_nodes
)[_idx_].outgoings)->data)) + (size_t)((reversed_nodes)[_idx_
].outgoings)->rsize * (size_t)(_j_))); if (_incomings_[d].
edges == 0) { _incomings_[d].edges = _bump_; _bump_ += _incomings_
[d].c; _incomings_[d].c = 0; } _edges_[_incomings_[d].edges -
 1 + _incomings_[d].c] = _idx_; ++_incomings_[d].c; if (_incomings_
[d].r != 2) continue; _incomings_[d].r = 3; ((void) sizeof ((
_exist_size_[_q_] < (exec_rnum)) ? 1 : 0), __extension__ (
{ if (_exist_size_[_q_] < (exec_rnum)) ; else __assert_fail
 ("_exist_size_[_q_] < (exec_rnum)", "ccv_cnnp_model_gradient_checkpointing.c"
, 288, __extension__ __PRETTY_FUNCTION__); })); _exists_[_q_]
[_exist_size_[_q_]] = d; ++_exist_size_[_q_]; } } ((_i_) = (_p_
), (_p_) = (_q_), (_q_) = (_i_)); } for (_i_ = 0; _i_ < (input_gradient_execs
->rnum); _i_++) { ((void) sizeof ((((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ? 1 : 0), __extension__ ({ if (((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ; else __assert_fail ("((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].graph == graph"
, "ccv_cnnp_model_gradient_checkpointing.c", 288, __extension__
 __PRETTY_FUNCTION__); })); _incomings_[((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].d].r =
 5; _exists_[0][_i_] = ((ccv_nnc_graph_exec_symbol_t*)((void*
)(((char*)((input_gradient_execs)->data)) + (size_t)(input_gradient_execs
)->rsize * (size_t)(0))))[_i_].d; } _exist_size_[0] = (input_gradient_execs
->rnum); _exist_size_[1] = 0; _p_ = 0, _q_ = 1; while (_exist_size_
[_p_] > 0) { _exist_size_[_q_] = 0; for (_i_ = 0; _i_ <
 _exist_size_[_p_]; _i_++) { const int32_t _idx_ = _exists_[_p_
][_i_]; if (_incomings_[_idx_].r != 5) continue; _incomings_[
_idx_].r = 6; if (_incomings_[_idx_].edges > 0) for (_j_ =
 0; _j_ < _incomings_[_idx_].c; _j_++) { const int d = _edges_
[_incomings_[_idx_].edges - 1 + _j_]; if (_incomings_[d].r !=
 4) continue; _incomings_[d].r = 5; ((void) sizeof ((_exist_size_
[_q_] < (exec_rnum)) ? 1 : 0), __extension__ ({ if (_exist_size_
[_q_] < (exec_rnum)) ; else __assert_fail ("_exist_size_[_q_] < (exec_rnum)"
, "ccv_cnnp_model_gradient_checkpointing.c", 288, __extension__
 __PRETTY_FUNCTION__); })); _exists_[_q_][_exist_size_[_q_]] =
 d; ++_exist_size_[_q_]; } } ((_i_) = (_p_), (_p_) = (_q_), (
_q_) = (_i_)); } for (_i_ = 0; _i_ < (input_gradient_execs
->rnum); _i_++) { ((void) sizeof ((((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ? 1 : 0), __extension__ ({ if (((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ; else __assert_fail ("((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].graph == graph"
, "ccv_cnnp_model_gradient_checkpointing.c", 288, __extension__
 __PRETTY_FUNCTION__); })); _incomings_[((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].d].d =
 1; } for (_i_ = 0; _i_ < (output_gradient_execs->rnum)
; _i_++) { ((void) sizeof ((((ccv_nnc_graph_exec_symbol_t*)((
void*)(((char*)((output_gradient_execs)->data)) + (size_t)
(output_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ? 1 : 0), __extension__ ({ if (((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ; else __assert_fail ("((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].graph == graph"
, "ccv_cnnp_model_gradient_checkpointing.c", 288, __extension__
 __PRETTY_FUNCTION__); })); _exists_[0][_i_] = ((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((output_gradient_execs)->data)) + (size_t
)(output_gradient_execs)->rsize * (size_t)(0))))[_i_].d; }
 _p_ = 0; _q_ = 1; _exist_size_[0] = (output_gradient_execs->
rnum); _exist_size_[1] = 0; int _d_ = 0; while (_exist_size_[
_p_] > 0) { _exist_size_[_q_] = 0; for (_i_ = 0; _i_ < _exist_size_
[_p_];) { const int32_t _idx_ = _exists_[_p_][_i_]; visitor((
(reversed_nodes) + _idx_), (_idx_), (_incomings_[_idx_].d)); if
 (_incomings_[_idx_].d) { ++_d_; _incomings_[_idx_].r = 7; } if
 ((reversed_nodes)[_idx_].outgoings) { if ((reversed_nodes)[_idx_
].outgoings->rnum == 1) { const int d = *(int*)((void*)(((
char*)(((reversed_nodes)[_idx_].outgoings)->data)) + (size_t
)((reversed_nodes)[_idx_].outgoings)->rsize * (size_t)(0))
); --_incomings_[d].c; if (_incomings_[d].c == 0 && _incomings_
[d].r == 6 && _d_ < (input_gradient_execs->rnum
)) { _exists_[_p_][_i_] = d; continue; } } else for (_j_ = 0;
 _j_ < (reversed_nodes)[_idx_].outgoings->rnum; _j_++) {
 const int d = *(int*)((void*)(((char*)(((reversed_nodes)[_idx_
].outgoings)->data)) + (size_t)((reversed_nodes)[_idx_].outgoings
)->rsize * (size_t)(_j_))); --_incomings_[d].c; if (_incomings_
[d].c == 0 && _incomings_[d].r == 6 && _d_ <
 (input_gradient_execs->rnum)) { ((void) sizeof ((_exist_size_
[_q_] < (exec_rnum)) ? 1 : 0), __extension__ ({ if (_exist_size_
[_q_] < (exec_rnum)) ; else __assert_fail ("_exist_size_[_q_] < (exec_rnum)"
, "ccv_cnnp_model_gradient_checkpointing.c", 288, __extension__
 __PRETTY_FUNCTION__); })); _exists_[_q_][_exist_size_[_q_]] =
 d; ++_exist_size_[_q_]; } } } ++_i_; } ((_i_) = (_p_), (_p_)
 = (_q_), (_q_) = (_i_)); } for (_i_ = 0; _i_ < (input_gradient_execs
->rnum); _i_++) { ((void) sizeof ((((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ? 1 : 0), __extension__ ({ if (((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].graph
 == graph) ; else __assert_fail ("((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].graph == graph"
, "ccv_cnnp_model_gradient_checkpointing.c", 288, __extension__
 __PRETTY_FUNCTION__); })); if (_incomings_[((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].d].r ==
 7) continue; if (!(0)) { ((void) sizeof ((_incomings_[((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].d].c ==
 0) ? 1 : 0), __extension__ ({ if (_incomings_[((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].d].c ==
 0) ; else __assert_fail ("_incomings_[((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].d].c == 0"
, "ccv_cnnp_model_gradient_checkpointing.c", 288, __extension__
 __PRETTY_FUNCTION__); })); } else if (_incomings_[((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].d].c >
 0) continue; visitor(((reversed_nodes) + ((ccv_nnc_graph_exec_symbol_t
*)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].d), (
((ccv_nnc_graph_exec_symbol_t*)((void*)(((char*)((input_gradient_execs
)->data)) + (size_t)(input_gradient_execs)->rsize * (size_t
)(0))))[_i_].d), (_incomings_[((ccv_nnc_graph_exec_symbol_t*)
((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(0))))[_i_].d].d)
); } if (_heap_mem_) free(_incomings_); } while (0);;
289		for (j = 0; j < input_gradient_execs->rnum; j++)
290			ccv_array_add_unique_int(visited_backward_execs, ((ccv_nnc_graph_exec_symbol_t*)ccv_array_get(input_gradient_execs, j)((void*)(((char*)((input_gradient_execs)->data)) + (size_t
)(input_gradient_execs)->rsize * (size_t)(j))))->d);
291#undef visitor
292		ccv_cnnp_gradient_checkpoint_build_t build = {
293			.tensor_context = {
294				.record = 1,
295				.tensor_symbols = ccv_array_new(sizeof(ccv_nnc_tensor_symbol_t), 0, 0),
296			},
297			.graph_exec_symbols = ccv_array_new(sizeof(ccv_nnc_graph_exec_symbol_t), 0, 0),
298			.all_tensor_symbols = ccv_array_new(sizeof(ccv_nnc_tensor_symbol_t), 0, 0),
299		};
300		build.tensor_context.old_tensor_symbol_new_hook_context = ccv_nnc_tensor_symbol_new_hook(graph, _ccv_cnnp_gradient_checkpoint_tensor_symbol_new_hook, &build, &build.tensor_context.old_tensor_symbol_new_hook);
301		build.tensor_context.old_tensor_symbol_alias_new_hook_context = ccv_nnc_tensor_symbol_alias_new_hook(graph, _ccv_cnnp_gradient_checkpoint_tensor_symbol_alias_new_hook, &build, &build.tensor_context.old_tensor_symbol_alias_new_hook);
302		build.old_graph_exec_symbol_new_hook_context = ccv_nnc_graph_exec_symbol_new_hook(graph, _ccv_cnnp_model_gradient_checkpoint_graph_exec_symbol_new_hook, &build, &build.old_graph_exec_symbol_new_hook);
303		ccv_array_clear(parameters);
304		ccv_array_clear(parameter_ids);
305		ccv_array_clear(parameter_trainables);
306		ccv_array_clear(internals);
307		ccv_array_clear(internal_ids);
308		ccv_cnnp_model_sequence_t model_sequence = {
309			.bank = kh_init(ccv_cnnp_model_name_bank)kh_init_ccv_cnnp_model_name_bank()
310		};
311		ccv_cnnp_model_add_to_array_context_t add_to_parameter_context = {
312			.sequence = &model_sequence,
313			.prefix = 't',
314			.symbols = parameters,
315			.ids = parameter_ids,
316			.trainables = parameter_trainables,
317		};
318		ccv_cnnp_model_add_to_array_context_t add_to_output_context = {
319			.sequence = &model_sequence,
320			.prefix = 'r',
321			.symbols = internals,
322			.ids = internal_ids,
323			.trainables = 0,
324		};
325		ccv_cnnp_model_build_data_t build_data = {
326			.is_trainable = checkpoint->is_trainable,
327			.model_sequence = &model_sequence,
328			.add_to_array = ccv_cnnp_model_add_to_array,
329			.parameters = parameters,
330			.context = {
331				.add_to_parameter = &add_to_parameter_context,
332				.add_to_output = &add_to_output_context,
333			},
334			.is_gradient_checkpointing = 1, // Mark this as true so we don't allocate gradient_checkpoints array or override the hooks.
335			.gradient_checkpoints = 0,
336		};
337		checkpoint->model->data = &build_data;
338		checkpoint->build(checkpoint->model, graph, checkpoint->inputs, checkpoint->input_size, max_outputs, checkpoint->output_size);
339		checkpoint->model->data = 0;
340		kh_destroy(ccv_cnnp_model_name_bank, model_sequence.bank)kh_destroy_ccv_cnnp_model_name_bank(model_sequence.bank);
341		if (model_sequence.sequences)
342			ccv_array_free(model_sequence.sequences);
343		ccv_nnc_tensor_symbol_new_hook(graph, build.tensor_context.old_tensor_symbol_new_hook, build.tensor_context.old_tensor_symbol_new_hook_context, 0);
344		ccv_nnc_tensor_symbol_alias_new_hook(graph, build.tensor_context.old_tensor_symbol_alias_new_hook, build.tensor_context.old_tensor_symbol_alias_new_hook_context, 0);
345		ccv_nnc_graph_exec_symbol_autogen(graph, (ccv_nnc_graph_exec_symbol_t*)ccv_array_get(build.graph_exec_symbols, 0)((void*)(((char*)((build.graph_exec_symbols)->data)) + (size_t
)(build.graph_exec_symbols)->rsize * (size_t)(0))), build.graph_exec_symbols->rnum, 0);
346		for (j = 0; j < parameter_ids->rnum; j++)
347			ccfreefree(*(char**)ccv_array_get(parameter_ids, j)((void*)(((char*)((parameter_ids)->data)) + (size_t)(parameter_ids
)->rsize * (size_t)(j))));
348		for (j = 0; j < internal_ids->rnum; j++)
349			ccfreefree(*(char**)ccv_array_get(internal_ids, j)((void*)(((char*)((internal_ids)->data)) + (size_t)(internal_ids
)->rsize * (size_t)(j))));
350		// Note that there is no graph optimization applied here.
351		exec_info = (ccv_nnc_graph_exec_symbol_info_t*)ccv_array_get(graph->exec_symbol_info, 0)((void*)(((char*)((graph->exec_symbol_info)->data)) + (
size_t)(graph->exec_symbol_info)->rsize * (size_t)(0)));
352		// Reuse existing one.
353		kh_clear(ccv_cnnp_tensor_symbol_set, newly_created_tensor_symbols)kh_clear_ccv_cnnp_tensor_symbol_set(newly_created_tensor_symbols
);
354		for (j = 0; j < build.tensor_context.tensor_symbols->rnum; j++)
355		{
356			const int idx = ((ccv_nnc_tensor_symbol_t*)ccv_array_get(build.tensor_context.tensor_symbols, j)((void*)(((char*)((build.tensor_context.tensor_symbols)->data
)) + (size_t)(build.tensor_context.tensor_symbols)->rsize *
 (size_t)(j))))->d;
357			if (idx < 0)
358				continue;
359			if (kh_get(ccv_cnnp_tensor_symbol_set, parameters_or_internals, idx)kh_get_ccv_cnnp_tensor_symbol_set(parameters_or_internals, idx
) != kh_end(parameters_or_internals)((parameters_or_internals)->n_buckets))
360				continue;
361			int ret;
362			kh_put(ccv_cnnp_tensor_symbol_set, newly_created_tensor_symbols, idx, &ret)kh_put_ccv_cnnp_tensor_symbol_set(newly_created_tensor_symbols
, idx, &ret);
363		}
364		ccv_array_t* const newly_input_execs = input_execs;
365		ccv_array_t* const newly_output_execs = output_execs;
366		ccv_array_clear(newly_input_execs);
367		ccv_array_clear(newly_output_execs);
368		for (j = 0; j < build.graph_exec_symbols->rnum; j++)
369		{
370			const int idx = ((ccv_nnc_graph_exec_symbol_t*)ccv_array_get(build.graph_exec_symbols, j)((void*)(((char*)((build.graph_exec_symbols)->data)) + (size_t
)(build.graph_exec_symbols)->rsize * (size_t)(j))))->d;
371			if (idx < 0)
372				continue;
373			if (CCV_NNC_GRAPH_EXEC_IS_DEAD(exec_info[idx].flags)((exec_info[idx].flags) & CCV_NNC_GRAPH_EXEC_DEAD))
374				continue;
375			const ccv_nnc_graph_exec_symbol_t symbol = {
376				.graph = graph,
377				.d = idx
378			};
379			const int* inputs = exec_info[idx].inputs;
380			int input_size = exec_info[idx].input_size;
381			// Only go through forward pass.
382			assert(!ccv_nnc_cmd_is_backward(exec_info[idx].cmd))((void) sizeof ((!ccv_nnc_cmd_is_backward(exec_info[idx].cmd)
) ? 1 : 0), __extension__ ({ if (!ccv_nnc_cmd_is_backward(exec_info
[idx].cmd)) ; else __assert_fail ("!ccv_nnc_cmd_is_backward(exec_info[idx].cmd)"
, "ccv_cnnp_model_gradient_checkpointing.c", 382, __extension__
 __PRETTY_FUNCTION__); }));
383			int flag = 0;
384			for (k = 0; inputs && k < input_size && !flag; k++)
385				if (inputs[k] >= 0)
386					for (l = 0; l < checkpoint->input_size && !flag; l++)
387						if (checkpoint->inputs[l].d >= 0 && inputs[k] == checkpoint->inputs[l].d)
388							flag = 1;
389			// Input logic is different from output logic. We need to filter out these exec that contains inputs from within the graph.
390			for (k = 0; inputs && k < input_size && flag; k++)
391				if (inputs[k] >= 0 && kh_get(ccv_cnnp_tensor_symbol_set, newly_created_tensor_symbols, inputs[k])kh_get_ccv_cnnp_tensor_symbol_set(newly_created_tensor_symbols
, inputs[k]) != kh_end(newly_created_tensor_symbols)((newly_created_tensor_symbols)->n_buckets))
392					flag = 0;
393			if (flag)
394				ccv_array_push(newly_input_execs, &symbol);
395			flag = 0;
396			const int* outputs = exec_info[idx].outputs;
397			int output_size = exec_info[idx].output_size;
398			for (k = 0; inputs && k < output_size && !flag; k++)
399				if (outputs[k] >= 0)
400					for (l = 0; l < checkpoint->output_size && !flag; l++)
401						if (max_outputs[l].d >= 0 && outputs[k] == max_outputs[l].d)
402							flag = 1;
403			if (flag)
404				ccv_array_push(newly_output_execs, &symbol);
405		}
406		for (j = 0; j < checkpoint->input_size; j++)
407			if (checkpoint->inputs[j].d >= 0)
408				ccv_array_push(parameters, checkpoint->inputs + j);
409		ccv_nnc_symbolic_graph_simplify(graph,
410			SYMBOLIC_GRAPH_PASSES(CCV_NNC_SIMPLIFY_COMMON_SUBEXPRESSION_ELIMINATION,(const int []){CCV_NNC_SIMPLIFY_COMMON_SUBEXPRESSION_ELIMINATION
, CCV_NNC_SIMPLIFY_DATA_TRANSFER_OPT, CCV_NNC_SIMPLIFY_OPS_FUSION
}, (1 +1 +1 +1 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +
0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0
 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +
0 +0 +0 +0 -1)
411				CCV_NNC_SIMPLIFY_DATA_TRANSFER_OPT,(const int []){CCV_NNC_SIMPLIFY_COMMON_SUBEXPRESSION_ELIMINATION
, CCV_NNC_SIMPLIFY_DATA_TRANSFER_OPT, CCV_NNC_SIMPLIFY_OPS_FUSION
}, (1 +1 +1 +1 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +
0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0
 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +
0 +0 +0 +0 -1)
412				CCV_NNC_SIMPLIFY_OPS_FUSION)(const int []){CCV_NNC_SIMPLIFY_COMMON_SUBEXPRESSION_ELIMINATION
, CCV_NNC_SIMPLIFY_DATA_TRANSFER_OPT, CCV_NNC_SIMPLIFY_OPS_FUSION
}, (1 +1 +1 +1 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +
0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0
 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0 +
0 +0 +0 +0 -1),
413			ccv_array_get(parameters, 0)((void*)(((char*)((parameters)->data)) + (size_t)(parameters
)->rsize * (size_t)(0))), parameters->rnum,
414			max_outputs, checkpoint->output_size,
415			ccv_array_get(newly_input_execs, 0)((void*)(((char*)((newly_input_execs)->data)) + (size_t)(newly_input_execs
)->rsize * (size_t)(0))), newly_input_execs->rnum, ccv_array_get(newly_output_execs, 0)((void*)(((char*)((newly_output_execs)->data)) + (size_t)(
newly_output_execs)->rsize * (size_t)(0))), newly_output_execs->rnum);
416		ccv_nnc_graph_exec_symbol_new_hook(graph, build.old_graph_exec_symbol_new_hook, build.old_graph_exec_symbol_new_hook_context, 0);
417		// Need to autogen and redo source / destination.
418		ccv_nnc_graph_exec_symbol_autogen(graph, (ccv_nnc_graph_exec_symbol_t*)ccv_array_get(build.graph_exec_symbols, 0)((void*)(((char*)((build.graph_exec_symbols)->data)) + (size_t
)(build.graph_exec_symbols)->rsize * (size_t)(0))), build.graph_exec_symbols->rnum, 0);
419		ccv_nnc_tensor_symbol_info_t* const tensor_symbol_info = (ccv_nnc_tensor_symbol_info_t*)ccv_array_get(graph->tensor_symbol_info, 0)((void*)(((char*)((graph->tensor_symbol_info)->data)) +
 (size_t)(graph->tensor_symbol_info)->rsize * (size_t)(
0)));
420		exec_info = (ccv_nnc_graph_exec_symbol_info_t*)ccv_array_get(graph->exec_symbol_info, 0)((void*)(((char*)((graph->exec_symbol_info)->data)) + (
size_t)(graph->exec_symbol_info)->rsize * (size_t)(0)));
421		ccv_array_clear(newly_input_execs);
422		for (j = 0; j < build.graph_exec_symbols->rnum; j++)
423		{
424			const int idx = ((ccv_nnc_graph_exec_symbol_t*)ccv_array_get(build.graph_exec_symbols, j)((void*)(((char*)((build.graph_exec_symbols)->data)) + (size_t
)(build.graph_exec_symbols)->rsize * (size_t)(j))))->d;
425			if (idx < 0)
426				continue;
427			if (CCV_NNC_GRAPH_EXEC_IS_DEAD(exec_info[idx].flags)((exec_info[idx].flags) & CCV_NNC_GRAPH_EXEC_DEAD))
428				continue;
429			const ccv_nnc_graph_exec_symbol_t symbol = {
430				.graph = graph,
431				.d = idx
432			};
433			const int* inputs = exec_info[idx].inputs;
434			int input_size = exec_info[idx].input_size;
435			// Only go through forward pass.
436			assert(!ccv_nnc_cmd_is_backward(exec_info[idx].cmd))((void) sizeof ((!ccv_nnc_cmd_is_backward(exec_info[idx].cmd)
) ? 1 : 0), __extension__ ({ if (!ccv_nnc_cmd_is_backward(exec_info
[idx].cmd)) ; else __assert_fail ("!ccv_nnc_cmd_is_backward(exec_info[idx].cmd)"
, "ccv_cnnp_model_gradient_checkpointing.c", 436, __extension__
 __PRETTY_FUNCTION__); }));
437			int flag = 0;
438			for (k = 0; inputs && k < input_size && !flag; k++)
439				if (inputs[k] >= 0)
440					for (l = 0; l < checkpoint->input_size && !flag; l++)
441						if (checkpoint->inputs[l].d >= 0 && inputs[k] == checkpoint->inputs[l].d)
442							flag = 1;
443			for (k = 0; inputs && k < input_size && flag; k++)
444				if (inputs[k] >= 0 && kh_get(ccv_cnnp_tensor_symbol_set, newly_created_tensor_symbols, inputs[k])kh_get_ccv_cnnp_tensor_symbol_set(newly_created_tensor_symbols
, inputs[k]) != kh_end(newly_created_tensor_symbols)((newly_created_tensor_symbols)->n_buckets))
445					flag = 0;
446			if (flag)
447				ccv_array_push(newly_input_execs, &symbol);
448		}
449		// Build a map between old tensor symbols and new tensor symbols.
450		assert(build.tensor_context.tensor_symbols->rnum <= checkpoint->tensor_symbols->rnum)((void) sizeof ((build.tensor_context.tensor_symbols->rnum
 <= checkpoint->tensor_symbols->rnum) ? 1 : 0), __extension__
 ({ if (build.tensor_context.tensor_symbols->rnum <= checkpoint
->tensor_symbols->rnum) ; else __assert_fail ("build.tensor_context.tensor_symbols->rnum <= checkpoint->tensor_symbols->rnum"
, "ccv_cnnp_model_gradient_checkpointing.c", 450, __extension__
 __PRETTY_FUNCTION__); }));
451		// Build a map to potentially map from old input to new input. 
452		kh_clear(ccv_cnnp_tensor_symbol_map, symbol_map)kh_clear_ccv_cnnp_tensor_symbol_map(symbol_map);
453		for (j = 0, k = 0; j < build.tensor_context.tensor_symbols->rnum && k < checkpoint->tensor_symbols->rnum;)
454		{
455			const int from_d = ((ccv_nnc_tensor_symbol_t*)ccv_array_get(checkpoint->tensor_symbols, k)((void*)(((char*)((checkpoint->tensor_symbols)->data)) +
 (size_t)(checkpoint->tensor_symbols)->rsize * (size_t)
(k))))->d;
456			if (from_d < 0) // This is removed, move to the next one.
457			{
458				++j;
459				++k;
460				continue;
461			}
462			const int to_d = ((ccv_nnc_tensor_symbol_t*)ccv_array_get(build.tensor_context.tensor_symbols, j)((void*)(((char*)((build.tensor_context.tensor_symbols)->data
)) + (size_t)(build.tensor_context.tensor_symbols)->rsize *
 (size_t)(j))))->d;
463			assert(to_d >= 0)((void) sizeof ((to_d >= 0) ? 1 : 0), __extension__ ({ if (
to_d >= 0) ; else __assert_fail ("to_d >= 0", "ccv_cnnp_model_gradient_checkpointing.c"
, 463, __extension__ __PRETTY_FUNCTION__); }));
464			int from_flag = kh_get(ccv_cnnp_tensor_symbol_set, parameters_or_internals, from_d)kh_get_ccv_cnnp_tensor_symbol_set(parameters_or_internals, from_d
) != kh_end(parameters_or_internals)((parameters_or_internals)->n_buckets);
465			int to_flag = kh_get(ccv_cnnp_tensor_symbol_set, parameters_or_internals, to_d)kh_get_ccv_cnnp_tensor_symbol_set(parameters_or_internals, to_d
) != kh_end(parameters_or_internals)((parameters_or_internals)->n_buckets);
466			if (from_flag)
467				++k;
468			if (to_flag)
469				++j;
470			if (from_flag || to_flag)
471				continue;
472			++k;
473			++j;
474			// Skip if from_d is outputs.
475			for (l = 0; l < !from_flag && checkpoint->output_size; l++)
476				if (checkpoint->outputs[l].d == from_d)
477					from_flag = 1;
478			if (from_flag)
479				continue;
480			// Skip if to_d is outputs.
481			for (l = 0; l < !to_flag && checkpoint->output_size; l++)
482				if (checkpoint->outputs[l].d == to_d)
483					to_flag = 1;
484			if (to_flag)
485				continue;
486			int ret = 0;
487			khiter_t h = kh_put(ccv_cnnp_tensor_symbol_map, symbol_map, from_d, &ret)kh_put_ccv_cnnp_tensor_symbol_map(symbol_map, from_d, &ret
);
488			kh_val(symbol_map, h)((symbol_map)->vals[h]) = to_d;
489		}
490		// Now go over all backward passes to replace inputs with the ones from symbol map. Record these that are used.
491		ccv_array_clear(newly_used_outputs);
492		ccv_array_clear(replaced_backward_execs);
493		for (j = 0; j < visited_backward_execs->rnum; j++)
494		{
495			const int idx = *(int*)ccv_array_get(visited_backward_execs, j)((void*)(((char*)((visited_backward_execs)->data)) + (size_t
)(visited_backward_execs)->rsize * (size_t)(j)));
496			if (CCV_NNC_GRAPH_EXEC_IS_DEAD(exec_info[idx].flags)((exec_info[idx].flags) & CCV_NNC_GRAPH_EXEC_DEAD))
497				continue;
498			assert(idx >= 0)((void) sizeof ((idx >= 0) ? 1 : 0), __extension__ ({ if (
idx >= 0) ; else __assert_fail ("idx >= 0", "ccv_cnnp_model_gradient_checkpointing.c"
, 498, __extension__ __PRETTY_FUNCTION__); }));
499			assert(idx < exec_rnum)((void) sizeof ((idx < exec_rnum) ? 1 : 0), __extension__ (
{ if (idx < exec_rnum) ; else __assert_fail ("idx < exec_rnum"
, "ccv_cnnp_model_gradient_checkpointing.c", 499, __extension__
 __PRETTY_FUNCTION__); }));
500			if (!ccv_nnc_cmd_is_backward(exec_info[idx].cmd))
501				continue;
502			for (k = 0; k < exec_info[idx].input_size; k++)
503				if (exec_info[idx].inputs[k] >= 0)
504				{
505					const khiter_t h = kh_get(ccv_cnnp_tensor_symbol_map, symbol_map, exec_info[idx].inputs[k])kh_get_ccv_cnnp_tensor_symbol_map(symbol_map, exec_info[idx].
inputs[k]);
506					if (h != kh_end(symbol_map)((symbol_map)->n_buckets)) // Replacing it.
507					{
508						int newly_created_output = kh_val(symbol_map, h)((symbol_map)->vals[h]);
509						exec_info[idx].inputs[k] = newly_created_output;
510						ccv_array_add_unique_int(newly_used_outputs, newly_created_output);
511						if (tensor_symbol_info[newly_created_output].alias_ref > 0)
512						{
513							newly_created_output = tensor_symbol_info[newly_created_output].alias_ref - 1;
514							ccv_array_add_unique_int(newly_used_outputs, newly_created_output);
515						}
516						ccv_array_add_unique_int(replaced_backward_execs, idx);
517					}
518				}
519		}
520		for (j = 0; j < build.graph_exec_symbols->rnum; j++)
521		{
522			ccv_nnc_graph_exec_symbol_t* const symbol = (ccv_nnc_graph_exec_symbol_t*)ccv_array_get(build.graph_exec_symbols, j)((void*)(((char*)((build.graph_exec_symbols)->data)) + (size_t
)(build.graph_exec_symbols)->rsize * (size_t)(j)));
523			if (symbol->d < 0)
524				continue;
525			if (CCV_NNC_GRAPH_EXEC_IS_DEAD(exec_info[symbol->d].flags)((exec_info[symbol->d].flags) & CCV_NNC_GRAPH_EXEC_DEAD
))
526				continue;
527			int x, y;
528			for (k = 0; k < replaced_backward_execs->rnum; k++)
529			{
530				const int idx = *(int*)ccv_array_get(replaced_backward_execs, k)((void*)(((char*)((replaced_backward_execs)->data)) + (size_t
)(replaced_backward_execs)->rsize * (size_t)(k)));
531				assert(idx >= 0)((void) sizeof ((idx >= 0) ? 1 : 0), __extension__ ({ if (
idx >= 0) ; else __assert_fail ("idx >= 0", "ccv_cnnp_model_gradient_checkpointing.c"
, 531, __extension__ __PRETTY_FUNCTION__); }));
532				assert(idx < exec_rnum)((void) sizeof ((idx < exec_rnum) ? 1 : 0), __extension__ (
{ if (idx < exec_rnum) ; else __assert_fail ("idx < exec_rnum"
, "ccv_cnnp_model_gradient_checkpointing.c", 532, __extension__
 __PRETTY_FUNCTION__); }));
533				assert(ccv_nnc_cmd_is_backward(exec_info[idx].cmd))((void) sizeof ((ccv_nnc_cmd_is_backward(exec_info[idx].cmd))
 ? 1 : 0), __extension__ ({ if (ccv_nnc_cmd_is_backward(exec_info
[idx].cmd)) ; else __assert_fail ("ccv_nnc_cmd_is_backward(exec_info[idx].cmd)"
, "ccv_cnnp_model_gradient_checkpointing.c", 533, __extension__
 __PRETTY_FUNCTION__); }));
534				int flag = 0;
535				for (x = 0; !flag && x < exec_info[idx].input_size; x++)
536				{
537					int x_d = exec_info[idx].inputs[x];
538					if (x_d < 0)
539						continue;
540					if (tensor_symbol_info[x_d].alias_ref > 0)
541						x_d = tensor_symbol_info[x_d].alias_ref - 1;
542					for (y = 0; !flag && y < exec_info[symbol->d].output_size; y++)
543					{
544						int y_d = exec_info[symbol->d].outputs[y];
545						if (y_d < 0)
546							continue;
547						if (tensor_symbol_info[y_d].alias_ref > 0)
548							y_d = tensor_symbol_info[y_d].alias_ref - 1;
549						if (x_d == y_d)
550							flag = 1;
551					}
552				}
553				if (flag)
554					ccv_nnc_graph_exec_symbol_concat(graph, *symbol, (ccv_nnc_graph_exec_symbol_t){
555						.graph = graph,
556						.d = idx
557					});
558			}
559		}
560		// Find parents to visited_backward_execs, and use that as the starting point of all newly added graph_exec_symbols. Use the visited backward execs as the source, use all its parents as destination, go through with graph visit.
561		ccv_sparse_matrix_t* const exec_dep = ccv_sparse_matrix_new(graph->exec_symbol_info->rnum, graph->exec_symbol_info->rnum, CCV_8U | CCV_C1, CCV_SPARSE_ROW_MAJOR, 0);
562#define for_block(x, val) \
563		do { \
564			if (((uint8_t*)val)[0] != 0) \
565				ccv_array_push(buf, &x); \
566		} while (0)
567		const uint8_t one = 1;
568		// Now go from outputs to inputs, unmark visited ones.
569		ccv_nnc_graph_visit_for(visit, exec_info, node, idx){ int _i_; for (_i_ = 0; _i_ < (visit)->size; _i_++) { const
 int idx __attribute__((unused)) = (visit)->node[_i_].index
; const int _node_unused_ __attribute__((unused)) = (visit)->
node[_i_].term; typeof ((exec_info)) const node __attribute__
((unused)) = (exec_info) + idx; {
570			if (idx < exec_rnum && !CCV_NNC_GRAPH_EXEC_IS_DEAD(node->flags)((node->flags) & CCV_NNC_GRAPH_EXEC_DEAD) && maskbit[idx >> 5] & (1u << (idx & 0x1f)))
571			{
572				ccv_array_clear(buf);
573				ccv_sparse_matrix_vector_t* vector = ccv_get_sparse_matrix_vector(exec_dep, idx);
574				if (vector)
575					CCV_SPARSE_VECTOR_FOREACH(exec_dep, vector, for_block)do { switch ((((exec_dep)->type) & 0xFF000)) { case CCV_32S
: { do { int _i_; __attribute__((unused)) const size_t _c_ = (
((exec_dep)->type) & 0xFFF); if ((exec_dep)->type &
 CCV_DENSE_VECTOR) { for (_i_ = 0; _i_ < (vector)->size
; _i_++) { for_block((_i_), ((vector)->data.i32 + (_i_ * _c_
))); } } else { const size_t _idx_size_ = sizeof(ccv_sparse_matrix_index_t
) + ((_ccv_get_data_type_size[(((exec_dep)->type) & 0xFF000
) >> 12] * (((exec_dep)->type) & 0xFFF) + 3) &
 -4); uint8_t* const _vidx_ = (uint8_t*)(vector)->index; for
 (_i_ = 0; _i_ < (vector)->size; _i_++) { ccv_sparse_matrix_index_t
* const _idx_i_ = (ccv_sparse_matrix_index_t*)(_vidx_ + _idx_size_
 * _i_); if (_idx_i_->ifbit <= 1) continue; ccv_numeric_data_t
 _d_ = { .u8 = (uint8_t*)(_idx_i_ + 1) }; for_block((_idx_i_->
i), (_d_.i32 + (0))); } } } while (0); break; } case CCV_32F:
 { do { int _i_; __attribute__((unused)) const size_t _c_ = (
((exec_dep)->type) & 0xFFF); if ((exec_dep)->type &
 CCV_DENSE_VECTOR) { for (_i_ = 0; _i_ < (vector)->size
; _i_++) { for_block((_i_), ((vector)->data.f32 + (_i_ * _c_
))); } } else { const size_t _idx_size_ = sizeof(ccv_sparse_matrix_index_t
) + ((_ccv_get_data_type_size[(((exec_dep)->type) & 0xFF000
) >> 12] * (((exec_dep)->type) & 0xFFF) + 3) &
 -4); uint8_t* const _vidx_ = (uint8_t*)(vector)->index; for
 (_i_ = 0; _i_ < (vector)->size; _i_++) { ccv_sparse_matrix_index_t
* const _idx_i_ = (ccv_sparse_matrix_index_t*)(_vidx_ + _idx_size_
 * _i_); if (_idx_i_->ifbit <= 1) continue; ccv_numeric_data_t
 _d_ = { .u8 = (uint8_t*)(_idx_i_ + 1) }; for_block((_idx_i_->
i), (_d_.f32 + (0))); } } } while (0); break; } case CCV_64S:
 { do { int _i_; __attribute__((unused)) const size_t _c_ = (
((exec_dep)->type) & 0xFFF); if ((exec_dep)->type &
 CCV_DENSE_VECTOR) { for (_i_ = 0; _i_ < (vector)->size
; _i_++) { for_block((_i_), ((vector)->data.i64 + (_i_ * _c_
))); } } else { const size_t _idx_size_ = sizeof(ccv_sparse_matrix_index_t
) + ((_ccv_get_data_type_size[(((exec_dep)->type) & 0xFF000
) >> 12] * (((exec_dep)->type) & 0xFFF) + 3) &
 -4); uint8_t* const _vidx_ = (uint8_t*)(vector)->index; for
 (_i_ = 0; _i_ < (vector)->size; _i_++) { ccv_sparse_matrix_index_t
* const _idx_i_ = (ccv_sparse_matrix_index_t*)(_vidx_ + _idx_size_
 * _i_); if (_idx_i_->ifbit <= 1) continue; ccv_numeric_data_t
 _d_ = { .u8 = (uint8_t*)(_idx_i_ + 1) }; for_block((_idx_i_->
i), (_d_.i64 + (0))); } } } while (0); break; } case CCV_64F:
 { do { int _i_; __attribute__((unused)) const size_t _c_ = (
((exec_dep)->type) & 0xFFF); if ((exec_dep)->type &
 CCV_DENSE_VECTOR) { for (_i_ = 0; _i_ < (vector)->size
; _i_++) { for_block((_i_), ((vector)->data.f64 + (_i_ * _c_
))); } } else { const size_t _idx_size_ = sizeof(ccv_sparse_matrix_index_t
) + ((_ccv_get_data_type_size[(((exec_dep)->type) & 0xFF000
) >> 12] * (((exec_dep)->type) & 0xFFF) + 3) &
 -4); uint8_t* const _vidx_ = (uint8_t*)(vector)->index; for
 (_i_ = 0; _i_ < (vector)->size; _i_++) { ccv_sparse_matrix_index_t
* const _idx_i_ = (ccv_sparse_matrix_index_t*)(_vidx_ + _idx_size_
 * _i_); if (_idx_i_->ifbit <= 1) continue; ccv_numeric_data_t
 _d_ = { .u8 = (uint8_t*)(_idx_i_ + 1) }; for_block((_idx_i_->
i), (_d_.f64 + (0))); } } } while (0); break; } default: { do
 { int _i_; __attribute__((unused)) const size_t _c_ = (((exec_dep
)->type) & 0xFFF); if ((exec_dep)->type & CCV_DENSE_VECTOR
) { for (_i_ = 0; _i_ < (vector)->size; _i_++) { for_block
((_i_), ((vector)->data.u8 + (_i_ * _c_))); } } else { const
 size_t _idx_size_ = sizeof(ccv_sparse_matrix_index_t) + ((_ccv_get_data_type_size
[(((exec_dep)->type) & 0xFF000) >> 12] * (((exec_dep
)->type) & 0xFFF) + 3) & -4); uint8_t* const _vidx_
 = (uint8_t*)(vector)->index; for (_i_ = 0; _i_ < (vector
)->size; _i_++) { ccv_sparse_matrix_index_t* const _idx_i_
 = (ccv_sparse_matrix_index_t*)(_vidx_ + _idx_size_ * _i_); if
 (_idx_i_->ifbit <= 1) continue; ccv_numeric_data_t _d_
 = { .u8 = (uint8_t*)(_idx_i_ + 1) }; for_block((_idx_i_->
i), (_d_.u8 + (0))); } } } while (0); } } } while (0);
576				if (node->outgoings && node->outgoings->rnum > 0)
577				{
578					ccv_array_t* const outgoings = node->outgoings;
579					for (k = 0; k < outgoings->rnum; k++)
580					{
581						const int outgoing_d = *(int*)ccv_array_get(outgoings, k)((void*)(((char*)((outgoings)->data)) + (size_t)(outgoings
)->rsize * (size_t)(k)));
582						if (outgoing_d >= exec_rnum)
583							continue;
584						int l;
585						// We cannot avoid the ones that visited, because these may not contain all the deps.
586						ccv_set_sparse_matrix_cell(exec_dep, outgoing_d, idx, &one);
587						for (l = 0; l < buf->rnum; l++)
588							ccv_set_sparse_matrix_cell(exec_dep, outgoing_d, *(int*)ccv_array_get(buf, l)((void*)(((char*)((buf)->data)) + (size_t)(buf)->rsize *
 (size_t)(l))), &one);
589					}
590				}
591			}
592		} ccv_nnc_graph_visit_endfor} }
593		// Now go from outputs to inputs, unmark visited ones.
594		ccv_nnc_graph_visit_for(visit, exec_info, node, idx){ int _i_; for (_i_ = 0; _i_ < (visit)->size; _i_++) { const
 int idx __attribute__((unused)) = (visit)->node[_i_].index
; const int _node_unused_ __attribute__((unused)) = (visit)->
node[_i_].term; typeof ((exec_info)) const node __attribute__
((unused)) = (exec_info) + idx; {
595			if (idx < exec_rnum)
596				maskbit[idx >> 5] &= ~(1u << (idx & 0x1f));
597		} ccv_nnc_graph_visit_endfor} }
598		ccv_nnc_graph_visit_free(visit);
599#undef for_block
600		// Go through visited backward execs, remove the ones that has no dependency on any replaced backward execs.
601		for (j = 0; j < visited_backward_execs->rnum;)
602		{
603			const int idx = *(int*)ccv_array_get(visited_backward_execs, j)((void*)(((char*)((visited_backward_execs)->data)) + (size_t
)(visited_backward_execs)->rsize * (size_t)(j)));
604			if (ccv_array_contain_int(replaced_backward_execs, idx))
605			{
606				++j;
607				continue;
608			}
609			ccv_sparse_matrix_vector_t* vector = ccv_get_sparse_matrix_vector(exec_dep, idx);
610			int flag = 0;
611#define for_block(x, val) \
612			do { \
613				if (((uint8_t*)val)[0] != 0) \
614					if (ccv_array_contain_int(replaced_backward_execs, x)) \
615						flag = 1; \
616			} while (0)
617			if (vector)
618				CCV_SPARSE_VECTOR_FOREACH(exec_dep, vector, for_block)do { switch ((((exec_dep)->type) & 0xFF000)) { case CCV_32S
: { do { int _i_; __attribute__((unused)) const size_t _c_ = (
((exec_dep)->type) & 0xFFF); if ((exec_dep)->type &
 CCV_DENSE_VECTOR) { for (_i_ = 0; _i_ < (vector)->size
; _i_++) { for_block((_i_), ((vector)->data.i32 + (_i_ * _c_
))); } } else { const size_t _idx_size_ = sizeof(ccv_sparse_matrix_index_t
) + ((_ccv_get_data_type_size[(((exec_dep)->type) & 0xFF000
) >> 12] * (((exec_dep)->type) & 0xFFF) + 3) &
 -4); uint8_t* const _vidx_ = (uint8_t*)(vector)->index; for
 (_i_ = 0; _i_ < (vector)->size; _i_++) { ccv_sparse_matrix_index_t
* const _idx_i_ = (ccv_sparse_matrix_index_t*)(_vidx_ + _idx_size_
 * _i_); if (_idx_i_->ifbit <= 1) continue; ccv_numeric_data_t
 _d_ = { .u8 = (uint8_t*)(_idx_i_ + 1) }; for_block((_idx_i_->
i), (_d_.i32 + (0))); } } } while (0); break; } case CCV_32F:
 { do { int _i_; __attribute__((unused)) const size_t _c_ = (
((exec_dep)->type) & 0xFFF); if ((exec_dep)->type &
 CCV_DENSE_VECTOR) { for (_i_ = 0; _i_ < (vector)->size
; _i_++) { for_block((_i_), ((vector)->data.f32 + (_i_ * _c_
))); } } else { const size_t _idx_size_ = sizeof(ccv_sparse_matrix_index_t
) + ((_ccv_get_data_type_size[(((exec_dep)->type) & 0xFF000
) >> 12] * (((exec_dep)->type) & 0xFFF) + 3) &
 -4); uint8_t* const _vidx_ = (uint8_t*)(vector)->index; for
 (_i_ = 0; _i_ < (vector)->size; _i_++) { ccv_sparse_matrix_index_t
* const _idx_i_ = (ccv_sparse_matrix_index_t*)(_vidx_ + _idx_size_
 * _i_); if (_idx_i_->ifbit <= 1) continue; ccv_numeric_data_t
 _d_ = { .u8 = (uint8_t*)(_idx_i_ + 1) }; for_block((_idx_i_->
i), (_d_.f32 + (0))); } } } while (0); break; } case CCV_64S:
 { do { int _i_; __attribute__((unused)) const size_t _c_ = (
((exec_dep)->type) & 0xFFF); if ((exec_dep)->type &
 CCV_DENSE_VECTOR) { for (_i_ = 0; _i_ < (vector)->size
; _i_++) { for_block((_i_), ((vector)->data.i64 + (_i_ * _c_
))); } } else { const size_t _idx_size_ = sizeof(ccv_sparse_matrix_index_t
) + ((_ccv_get_data_type_size[(((exec_dep)->type) & 0xFF000
) >> 12] * (((exec_dep)->type) & 0xFFF) + 3) &
 -4); uint8_t* const _vidx_ = (uint8_t*)(vector)->index; for
 (_i_ = 0; _i_ < (vector)->size; _i_++) { ccv_sparse_matrix_index_t
* const _idx_i_ = (ccv_sparse_matrix_index_t*)(_vidx_ + _idx_size_
 * _i_); if (_idx_i_->ifbit <= 1) continue; ccv_numeric_data_t
 _d_ = { .u8 = (uint8_t*)(_idx_i_ + 1) }; for_block((_idx_i_->
i), (_d_.i64 + (0))); } } } while (0); break; } case CCV_64F:
 { do { int _i_; __attribute__((unused)) const size_t _c_ = (
((exec_dep)->type) & 0xFFF); if ((exec_dep)->type &
 CCV_DENSE_VECTOR) { for (_i_ = 0; _i_ < (vector)->size
; _i_++) { for_block((_i_), ((vector)->data.f64 + (_i_ * _c_
))); } } else { const size_t _idx_size_ = sizeof(ccv_sparse_matrix_index_t
) + ((_ccv_get_data_type_size[(((exec_dep)->type) & 0xFF000
) >> 12] * (((exec_dep)->type) & 0xFFF) + 3) &
 -4); uint8_t* const _vidx_ = (uint8_t*)(vector)->index; for
 (_i_ = 0; _i_ < (vector)->size; _i_++) { ccv_sparse_matrix_index_t
* const _idx_i_ = (ccv_sparse_matrix_index_t*)(_vidx_ + _idx_size_
 * _i_); if (_idx_i_->ifbit <= 1) continue; ccv_numeric_data_t
 _d_ = { .u8 = (uint8_t*)(_idx_i_ + 1) }; for_block((_idx_i_->
i), (_d_.f64 + (0))); } } } while (0); break; } default: { do
 { int _i_; __attribute__((unused)) const size_t _c_ = (((exec_dep
)->type) & 0xFFF); if ((exec_dep)->type & CCV_DENSE_VECTOR
) { for (_i_ = 0; _i_ < (vector)->size; _i_++) { for_block
((_i_), ((vector)->data.u8 + (_i_ * _c_))); } } else { const
 size_t _idx_size_ = sizeof(ccv_sparse_matrix_index_t) + ((_ccv_get_data_type_size
[(((exec_dep)->type) & 0xFF000) >> 12] * (((exec_dep
)->type) & 0xFFF) + 3) & -4); uint8_t* const _vidx_
 = (uint8_t*)(vector)->index; for (_i_ = 0; _i_ < (vector
)->size; _i_++) { ccv_sparse_matrix_index_t* const _idx_i_
 = (ccv_sparse_matrix_index_t*)(_vidx_ + _idx_size_ * _i_); if
 (_idx_i_->ifbit <= 1) continue; ccv_numeric_data_t _d_
 = { .u8 = (uint8_t*)(_idx_i_ + 1) }; for_block((_idx_i_->
i), (_d_.u8 + (0))); } } } while (0); } } } while (0);
619#undef for_block
620			if (!flag)
621			{
622				if (j < visited_backward_execs->rnum - 1)
623					*(int*)ccv_array_get(visited_backward_execs, j)((void*)(((char*)((visited_backward_execs)->data)) + (size_t
)(visited_backward_execs)->rsize * (size_t)(j))) = *(int*)ccv_array_get(visited_backward_execs, visited_backward_execs->rnum - 1)((void*)(((char*)((visited_backward_execs)->data)) + (size_t
)(visited_backward_execs)->rsize * (size_t)(visited_backward_execs
->rnum - 1)));
624				--visited_backward_execs->rnum;
625				continue;
626			}
627			++j;
628		}
629		// Now go through all replaced_backward_execs to find the ones has no dependencies in visited_backward_execs.
630		for (j = 0; j < replaced_backward_execs->rnum; j++)
631		{
632			const int idx = *(int*)ccv_array_get(replaced_backward_execs, j)((void*)(((char*)((replaced_backward_execs)->data)) + (size_t
)(replaced_backward_execs)->rsize * (size_t)(j)));
633			ccv_sparse_matrix_vector_t* vector = ccv_get_sparse_matrix_vector(exec_dep, idx);
634			int flag = 0;
635#define for_block(x, val) \
636			do { \
637				if (((uint8_t*)val)[0] != 0) \
638					if (ccv_array_contain_int(visited_backward_execs, x)) \
639						flag = 1; \
640			} while (0)
641			if (vector)
642				CCV_SPARSE_VECTOR_FOREACH(exec_dep, vector, for_block)do { switch ((((exec_dep)->type) & 0xFF000)) { case CCV_32S
: { do { int _i_; __attribute__((unused)) const size_t _c_ = (
((exec_dep)->type) & 0xFFF); if ((exec_dep)->type &
 CCV_DENSE_VECTOR) { for (_i_ = 0; _i_ < (vector)->size
; _i_++) { for_block((_i_), ((vector)->data.i32 + (_i_ * _c_
))); } } else { const size_t _idx_size_ = sizeof(ccv_sparse_matrix_index_t
) + ((_ccv_get_data_type_size[(((exec_dep)->type) & 0xFF000
) >> 12] * (((exec_dep)->type) & 0xFFF) + 3) &
 -4); uint8_t* const _vidx_ = (uint8_t*)(vector)->index; for
 (_i_ = 0; _i_ < (vector)->size; _i_++) { ccv_sparse_matrix_index_t
* const _idx_i_ = (ccv_sparse_matrix_index_t*)(_vidx_ + _idx_size_
 * _i_); if (_idx_i_->ifbit <= 1) continue; ccv_numeric_data_t
 _d_ = { .u8 = (uint8_t*)(_idx_i_ + 1) }; for_block((_idx_i_->
i), (_d_.i32 + (0))); } } } while (0); break; } case CCV_32F:
 { do { int _i_; __attribute__((unused)) const size_t _c_ = (
((exec_dep)->type) & 0xFFF); if ((exec_dep)->type &
 CCV_DENSE_VECTOR) { for (_i_ = 0; _i_ < (vector)->size
; _i_++) { for_block((_i_), ((vector)->data.f32 + (_i_ * _c_
))); } } else { const size_t _idx_size_ = sizeof(ccv_sparse_matrix_index_t
) + ((_ccv_get_data_type_size[(((exec_dep)->type) & 0xFF000
) >> 12] * (((exec_dep)->type) & 0xFFF) + 3) &
 -4); uint8_t* const _vidx_ = (uint8_t*)(vector)->index; for
 (_i_ = 0; _i_ < (vector)->size; _i_++) { ccv_sparse_matrix_index_t
* const _idx_i_ = (ccv_sparse_matrix_index_t*)(_vidx_ + _idx_size_
 * _i_); if (_idx_i_->ifbit <= 1) continue; ccv_numeric_data_t
 _d_ = { .u8 = (uint8_t*)(_idx_i_ + 1) }; for_block((_idx_i_->
i), (_d_.f32 + (0))); } } } while (0); break; } case CCV_64S:
 { do { int _i_; __attribute__((unused)) const size_t _c_ = (
((exec_dep)->type) & 0xFFF); if ((exec_dep)->type &
 CCV_DENSE_VECTOR) { for (_i_ = 0; _i_ < (vector)->size
; _i_++) { for_block((_i_), ((vector)->data.i64 + (_i_ * _c_
))); } } else { const size_t _idx_size_ = sizeof(ccv_sparse_matrix_index_t
) + ((_ccv_get_data_type_size[(((exec_dep)->type) & 0xFF000
) >> 12] * (((exec_dep)->type) & 0xFFF) + 3) &
 -4); uint8_t* const _vidx_ = (uint8_t*)(vector)->index; for
 (_i_ = 0; _i_ < (vector)->size; _i_++) { ccv_sparse_matrix_index_t
* const _idx_i_ = (ccv_sparse_matrix_index_t*)(_vidx_ + _idx_size_
 * _i_); if (_idx_i_->ifbit <= 1) continue; ccv_numeric_data_t
 _d_ = { .u8 = (uint8_t*)(_idx_i_ + 1) }; for_block((_idx_i_->
i), (_d_.i64 + (0))); } } } while (0); break; } case CCV_64F:
 { do { int _i_; __attribute__((unused)) const size_t _c_ = (
((exec_dep)->type) & 0xFFF); if ((exec_dep)->type &
 CCV_DENSE_VECTOR) { for (_i_ = 0; _i_ < (vector)->size
; _i_++) { for_block((_i_), ((vector)->data.f64 + (_i_ * _c_
))); } } else { const size_t _idx_size_ = sizeof(ccv_sparse_matrix_index_t
) + ((_ccv_get_data_type_size[(((exec_dep)->type) & 0xFF000
) >> 12] * (((exec_dep)->type) & 0xFFF) + 3) &
 -4); uint8_t* const _vidx_ = (uint8_t*)(vector)->index; for
 (_i_ = 0; _i_ < (vector)->size; _i_++) { ccv_sparse_matrix_index_t
* const _idx_i_ = (ccv_sparse_matrix_index_t*)(_vidx_ + _idx_size_
 * _i_); if (_idx_i_->ifbit <= 1) continue; ccv_numeric_data_t
 _d_ = { .u8 = (uint8_t*)(_idx_i_ + 1) }; for_block((_idx_i_->
i), (_d_.f64 + (0))); } } } while (0); break; } default: { do
 { int _i_; __attribute__((unused)) const size_t _c_ = (((exec_dep
)->type) & 0xFFF); if ((exec_dep)->type & CCV_DENSE_VECTOR
) { for (_i_ = 0; _i_ < (vector)->size; _i_++) { for_block
((_i_), ((vector)->data.u8 + (_i_ * _c_))); } } else { const
 size_t _idx_size_ = sizeof(ccv_sparse_matrix_index_t) + ((_ccv_get_data_type_size
[(((exec_dep)->type) & 0xFF000) >> 12] * (((exec_dep
)->type) & 0xFFF) + 3) & -4); uint8_t* const _vidx_
 = (uint8_t*)(vector)->index; for (_i_ = 0; _i_ < (vector
)->size; _i_++) { ccv_sparse_matrix_index_t* const _idx_i_
 = (ccv_sparse_matrix_index_t*)(_vidx_ + _idx_size_ * _i_); if
 (_idx_i_->ifbit <= 1) continue; ccv_numeric_data_t _d_
 = { .u8 = (uint8_t*)(_idx_i_ + 1) }; for_block((_idx_i_->
i), (_d_.u8 + (0))); } } } while (0); } } } while (0);
643#undef for_block
644			// If this one has no parents that is within the visited_backward_execs, it is a good place for us to add all its parents as dependency for input_execs.
645			if (!flag)
646			{
647				assert(idx < exec_rnum)((void) sizeof ((idx < exec_rnum) ? 1 : 0), __extension__ (
{ if (idx < exec_rnum) ; else __assert_fail ("idx < exec_rnum"
, "ccv_cnnp_model_gradient_checkpointing.c", 647, __extension__
 __PRETTY_FUNCTION__); }));
648				ccv_array_t* const outgoings = reversed_nodes[idx].outgoings;
649				assert(outgoings)((void) sizeof ((outgoings) ? 1 : 0), __extension__ ({ if (outgoings
) ; else __assert_fail ("outgoings", "ccv_cnnp_model_gradient_checkpointing.c"
, 649, __extension__ __PRETTY_FUNCTION__); }));
650				for (k = 0; k < outgoings->rnum; k++)
651				{
652					const int d = *(int*)ccv_array_get(outgoings, k)((void*)(((char*)((outgoings)->data)) + (size_t)(outgoings
)->rsize * (size_t)(k)));
653					for (l = 0; l < newly_input_execs->rnum; l++)
654					{
655						ccv_nnc_graph_exec_symbol_concat(graph, (ccv_nnc_graph_exec_symbol_t){
656							.graph = graph,
657							.d = d
658						}, *(ccv_nnc_graph_exec_symbol_t*)ccv_array_get(newly_input_execs, l)((void*)(((char*)((newly_input_execs)->data)) + (size_t)(newly_input_execs
)->rsize * (size_t)(l))));
659					}
660				}
661			}
662		}
663		ccv_matrix_free(exec_dep);
664		// Go through all exec, free ones that doesn't have output used.
665		// Reuse this array because it is not useful any more.
666		ccv_array_t* forward_pass_inputs = visited_backward_execs;
667		int any_deleted;
668		do {
669			// Build a map of still active inputs.
670			ccv_array_clear(forward_pass_inputs);
671			for (j = 0; j < build.graph_exec_symbols->rnum; j++)
672			{
673				ccv_nnc_graph_exec_symbol_t* const symbol = (ccv_nnc_graph_exec_symbol_t*)ccv_array_get(build.graph_exec_symbols, j)((void*)(((char*)((build.graph_exec_symbols)->data)) + (size_t
)(build.graph_exec_symbols)->rsize * (size_t)(j)));
674				if (symbol->d < 0)
675					continue;
676				if (CCV_NNC_GRAPH_EXEC_IS_DEAD(exec_info[symbol->d].flags)((exec_info[symbol->d].flags) & CCV_NNC_GRAPH_EXEC_DEAD
))
677					continue;
678				int* const inputs = exec_info[symbol->d].inputs;
679				const int input_size = exec_info[symbol->d].input_size;
680				for (k = 0; k < input_size; k++)
681				{
682					int d = inputs[k];
683					if (d < 0)
684						continue;
685					ccv_array_add_unique_int(forward_pass_inputs, d);
686					if (tensor_symbol_info[d].alias_ref > 0)
687					{
688						d = tensor_symbol_info[d].alias_ref - 1;
689						ccv_array_add_unique_int(forward_pass_inputs, d);
690					}
691				}
692			}
693			any_deleted = 0;
694			for (j = 0; j < build.graph_exec_symbols->rnum; j++)
695			{
696				ccv_nnc_graph_exec_symbol_t* const symbol = (ccv_nnc_graph_exec_symbol_t*)ccv_array_get(build.graph_exec_symbols, j)((void*)(((char*)((build.graph_exec_symbols)->data)) + (size_t
)(build.graph_exec_symbols)->rsize * (size_t)(j)));
697				if (symbol->d < 0)
698					continue;
699				if (CCV_NNC_GRAPH_EXEC_IS_DEAD(exec_info[symbol->d].flags)((exec_info[symbol->d].flags) & CCV_NNC_GRAPH_EXEC_DEAD
))
700					continue;
701				int* const outputs = exec_info[symbol->d].outputs;
702				const int output_size = exec_info[symbol->d].output_size;
703				int flag = 0;
704				for (k = 0; !flag && k < output_size; k++)
705				{
706					int d = outputs[k];
707					if (d < 0)
708						continue;
709					flag = ccv_array_contain_int(newly_used_outputs, d) || ccv_array_contain_int(forward_pass_inputs, d);
710					if (!flag && tensor_symbol_info[d].alias_ref > 0)
711					{
712						d = tensor_symbol_info[d].alias_ref - 1;
713						flag = ccv_array_contain_int(newly_used_outputs, d) || ccv_array_contain_int(forward_pass_inputs, d);
714					}
715				}
716				if (flag)
717					continue;
718				ccv_nnc_graph_exec_symbol_free(graph, *symbol);
719				symbol->d = -1;
720				symbol->graph = 0;
721				any_deleted = 1;
722			}
723		} while (any_deleted);
724		ccv_array_clear(forward_pass_inputs);
725		for (j = 0; j < build.graph_exec_symbols->rnum; j++)
726		{
727			ccv_nnc_graph_exec_symbol_t* const symbol = (ccv_nnc_graph_exec_symbol_t*)ccv_array_get(build.graph_exec_symbols, j)((void*)(((char*)((build.graph_exec_symbols)->data)) + (size_t
)(build.graph_exec_symbols)->rsize * (size_t)(j)));
728			if (symbol->d < 0)
729				continue;
730			if (CCV_NNC_GRAPH_EXEC_IS_DEAD(exec_info[symbol->d].flags)((exec_info[symbol->d].flags) & CCV_NNC_GRAPH_EXEC_DEAD
))
731				continue;
732			int* const inputs = exec_info[symbol->d].inputs;
733			const int input_size = exec_info[symbol->d].input_size;
734			for (k = 0; k < input_size; k++)
735			{
736				if (inputs[k] < 0)
737					continue;
738				ccv_array_add_unique_int(forward_pass_inputs, inputs[k]);
739				if (tensor_symbol_info[inputs[k]].alias_ref > 0)
740					ccv_array_add_unique_int(forward_pass_inputs, tensor_symbol_info[inputs[k]].alias_ref - 1);
741			}
742			int* const outputs = exec_info[symbol->d].outputs;
743			const int output_size = exec_info[symbol->d].output_size;
744			for (k = 0; k < output_size; k++)
745			{
746				if (outputs[k] < 0)
747					continue;
748				ccv_array_add_unique_int(forward_pass_inputs, outputs[k]);
749				if (tensor_symbol_info[outputs[k]].alias_ref > 0)
750					ccv_array_add_unique_int(forward_pass_inputs, tensor_symbol_info[outputs[k]].alias_ref - 1);
751			}
752		}
753		// Free unused tensor symbols.
754		for (j = 0; j < build.all_tensor_symbols->rnum; j++)
755		{
756			const ccv_nnc_tensor_symbol_t* symbol = ((ccv_nnc_tensor_symbol_t*)ccv_array_get(build.all_tensor_symbols, j)((void*)(((char*)((build.all_tensor_symbols)->data)) + (size_t
)(build.all_tensor_symbols)->rsize * (size_t)(j))));
757			if (ccv_array_contain_int(newly_used_outputs, symbol->d) || ccv_array_contain_int(forward_pass_inputs, symbol->d))
758				continue;
759			if (tensor_symbol_info[symbol->d].alias_ref > 0)
760			{
761				const int d = tensor_symbol_info[symbol->d].alias_ref - 1;
762				if (ccv_array_contain_int(newly_used_outputs, d) || ccv_array_contain_int(forward_pass_inputs, d))
763					continue;
764			}
765			ccv_nnc_tensor_symbol_free(graph, *symbol);
766		}
767		for (j = 0; j < build.graph_exec_symbols->rnum; j++)
768		{
769			ccv_nnc_graph_exec_symbol_t* const symbol = (ccv_nnc_graph_exec_symbol_t*)ccv_array_get(build.graph_exec_symbols, j)((void*)(((char*)((build.graph_exec_symbols)->data)) + (size_t
)(build.graph_exec_symbols)->rsize * (size_t)(j)));
770			if (symbol->d < 0)
771				continue;
772			if (CCV_NNC_GRAPH_EXEC_IS_DEAD(exec_info[symbol->d].flags)((exec_info[symbol->d].flags) & CCV_NNC_GRAPH_EXEC_DEAD
))
773				continue;
774			ccv_nnc_graph_exec_symbol_set_flags(graph, *symbol, CCV_NNC_GRAPH_EXEC_DISABLE_OPT);
775		}
776		// Free these newly created execs and tensor symbols.
777		ccv_array_free(build.tensor_context.tensor_symbols);
778		ccv_array_free(build.graph_exec_symbols);
779		ccv_array_free(build.all_tensor_symbols);
780	}
781	kh_destroy(ccv_cnnp_tensor_symbol_map, symbol_map)kh_destroy_ccv_cnnp_tensor_symbol_map(symbol_map);
782	kh_destroy(ccv_cnnp_tensor_symbol_set, newly_created_tensor_symbols)kh_destroy_ccv_cnnp_tensor_symbol_set(newly_created_tensor_symbols
);
783	kh_destroy(ccv_cnnp_tensor_symbol_set, parameters_or_internals)kh_destroy_ccv_cnnp_tensor_symbol_set(parameters_or_internals
);
784	ccfreefree(max_outputs);
785	ccv_array_free(buf);
786	ccv_array_free(newly_used_outputs);
787	ccv_array_free(parameters);
788	ccv_array_free(parameter_ids);
789	ccv_array_free(parameter_trainables);
790	ccv_array_free(internals);
791	ccv_array_free(internal_ids);
792	ccfreefree(maskbit);
793	ccv_array_free(input_gradient_execs);
794	ccv_array_free(output_gradient_execs);
795	ccv_array_free(input_execs);
796	ccv_array_free(output_execs);
797	ccv_array_free(replaced_backward_execs);
798	ccv_array_free(visited_backward_execs);
799	for (i = 0; i < exec_rnum; i++)
800		if (reversed_nodes[i].outgoings)
801			ccv_array_free(reversed_nodes[i].outgoings);
802	ccfreefree(reversed_nodes);
803}