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Avoid unaligned memory access while testing SSE4.2 CRC intrinsics

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This commit is contained in:
Anonymous Maarten
2026-04-02 20:11:54 +02:00
committed by Anonymous Maarten
parent df72e3f59d
commit f7661ff016
1 changed files with 20 additions and 3 deletions
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23
test/testautomation_intrinsics.c
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@@ -256,11 +256,26 @@ SDL_TARGETING("sse4.2") static Uint32 calculate_crc32c_sse4_2(const char *text)
Uint32 crc32c = ~0u;
size_t len = SDL_strlen(text);
if (len >= 1 && ((uintptr_t)text & 0x1)) {
crc32c = (Uint32)_mm_crc32_u8(crc32c, *text);
len -= 1;
text += 1;
}
if (len >= 2 && ((uintptr_t)text & 0x2)) {
crc32c = (Uint32)_mm_crc32_u16(crc32c, *(Sint16*)text);
len -= 2;
text += 2;
}
#if defined(__x86_64__) || defined(_M_X64)
if (len >= 4 && ((uintptr_t)text & 0x4)) {
crc32c = (Uint32)_mm_crc32_u32(crc32c, *(Sint32*)text);
len -= 4;
text += 4;
}
for (; len >= 8; len -= 8, text += 8) {
crc32c = (Uint32)_mm_crc32_u64(crc32c, *(Sint64*)text);
}
if (len >= 4) {
if (len & 0x4) {
crc32c = (Uint32)_mm_crc32_u32(crc32c, *(Sint32*)text);
len -= 4;
text += 4;
@@ -270,13 +285,15 @@ SDL_TARGETING("sse4.2") static Uint32 calculate_crc32c_sse4_2(const char *text)
crc32c = (Uint32)_mm_crc32_u32(crc32c, *(Sint32*)text);
}
#endif
if (len >= 2) {
if (len & 0x2) {
crc32c = (Uint32)_mm_crc32_u16(crc32c, *(Sint16*)text);
len -= 2;
text += 2;
}
if (len) {
if (len & 0x1) {
crc32c = (Uint32)_mm_crc32_u8(crc32c, *text);
len -= 1;
text += 1;
}
return ~crc32c;
}