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wasm2c: improve amortized speed of memory.grow

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Jacob Young 2022-12-06 02:16:29 -05:00 • committed by Andrew Kelley
parent 3686787f67
commit 3683602226
1 changed files with 21 additions and 11 deletions
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32
stage1/wasm2c.c
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@ -91,7 +91,7 @@ int main(int argc, char **argv) {
InputStream_readByte(&in) != 'm') panic("input is not a zstd-compressed wasm file"); InputStream_readByte(&in) != 'm') panic("input is not a zstd-compressed wasm file");
if (InputStream_readLittle_u32(&in) != 1) panic("unsupported wasm version"); if (InputStream_readLittle_u32(&in) != 1) panic("unsupported wasm version");
FILE *out = fopen(argv[2], "w"); FILE *out = fopen(argv[2], "wb");
if (out == NULL) panic("unable to open output file"); if (out == NULL) panic("unable to open output file");
fputs("#include <math.h>\n" fputs("#include <math.h>\n"
"#include <stdint.h>\n" "#include <stdint.h>\n"
@ -225,14 +225,22 @@ int main(int argc, char **argv) {
" return dst;\n" " return dst;\n"
"}\n" "}\n"
"\n" "\n"
"static uint32_t memory_grow(uint8_t **m, uint32_t *p, uint32_t n) {\n" "static uint32_t memory_grow(uint8_t **m, uint32_t *p, uint32_t *c, uint32_t n) {\n"
" uint8_t *new_m = *m;\n"
" uint32_t r = *p;\n" " uint32_t r = *p;\n"
" uint32_t new_p = r + n;\n" " uint32_t new_p = r + n;\n"
" uint8_t *new_m = realloc(*m, new_p << 16);\n" " if (new_p > UINT32_C(0x10000)) return UINT32_C(0xFFFFFFF);\n"
" if (new_m == NULL) return UINT32_C(0xFFFFFFF);\n" " uint32_t new_c = *c;\n"
" memset(&new_m[r << 16], 0, n << 16);\n" " if (new_c < new_p) {\n"
" *m = new_m;\n" " do new_c += new_c / 2 + 8; while (new_c < new_p);\n"
" if (new_c > UINT32_C(0x10000)) new_c = UINT32_C(0x10000);\n"
" new_m = realloc(new_m, new_c << 16);\n"
" if (new_m == NULL) return UINT32_C(0xFFFFFFF);\n"
" *m = new_m;\n"
" *c = new_c;\n"
" }\n"
" *p = new_p;\n" " *p = new_p;\n"
" memset(&new_m[r << 16], 0, n << 16);\n"
" return r;\n" " return r;\n"
"}\n" "}\n"
"\n" "\n"
@ -369,7 +377,8 @@ int main(int argc, char **argv) {
for (uint32_t i = 0; i < mems_len; i += 1) { for (uint32_t i = 0; i < mems_len; i += 1) {
mems[i].limits = InputStream_readLimits(&in); mems[i].limits = InputStream_readLimits(&in);
fprintf(out, "static uint8_t *m%" PRIu32 ";\n" fprintf(out, "static uint8_t *m%" PRIu32 ";\n"
"static uint32_t p%" PRIu32 ";\n", i, i); "static uint32_t p%" PRIu32 ";\n"
"static uint32_t c%" PRIu32 ";\n", i, i, i);
} }
fputc('\n', out); fputc('\n', out);
} }
@ -1319,8 +1328,8 @@ int main(int argc, char **argv) {
if (unreachable_depth == 0) { if (unreachable_depth == 0) {
uint32_t pages = FuncGen_stackPop(&fg); uint32_t pages = FuncGen_stackPop(&fg);
FuncGen_stackPush(&fg, out, WasmValType_i32); FuncGen_stackPush(&fg, out, WasmValType_i32);
fprintf(out, "memory_grow(&m%" PRIu32 ", &p%" PRIu32 ", l%" PRIu32 ");\n", fprintf(out, "memory_grow(&m%" PRIu32 ", &p%" PRIu32 ", &c%" PRIu32
mem_idx, mem_idx, pages); ", l%" PRIu32 ");\n", mem_idx, mem_idx, mem_idx, pages);
} }
break; break;
} }
@ -2449,8 +2458,9 @@ int main(int argc, char **argv) {
fputs("static void init_data(void) {\n", out); fputs("static void init_data(void) {\n", out);
for (uint32_t i = 0; i < mems_len; i += 1) for (uint32_t i = 0; i < mems_len; i += 1)
fprintf(out, " p%" PRIu32 " = UINT32_C(%" PRIu32 ");\n" fprintf(out, " p%" PRIu32 " = UINT32_C(%" PRIu32 ");\n"
" m%" PRIu32 " = calloc(p%" PRIu32 ", UINT32_C(1) << 16);\n", " c%" PRIu32 " = p%" PRIu32 ";\n"
i, mems[i].limits.min, i, i); " m%" PRIu32 " = calloc(c%" PRIu32 ", UINT32_C(1) << 16);\n",
i, mems[i].limits.min, i, i, i, i);
for (uint32_t segment_i = 0; segment_i < len; segment_i += 1) { for (uint32_t segment_i = 0; segment_i < len; segment_i += 1) {
uint32_t mem_idx; uint32_t mem_idx;
switch (InputStream_readLeb128_u32(&in)) { switch (InputStream_readLeb128_u32(&in)) {