From 2d660108b27a5c03ea8bd8bbd70a0aa3054b995a Mon Sep 17 00:00:00 2001 From: ocornut Date: Wed, 27 Nov 2024 12:34:16 +0100 Subject: [PATCH] Misc: amend crc32 to use _mm_crc32_u32. (#8169, #4933) --- imgui.cpp | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/imgui.cpp b/imgui.cpp index ff5d25408cc7..5f6c859007c5 100644 --- a/imgui.cpp +++ b/imgui.cpp @@ -2183,13 +2183,19 @@ ImGuiID ImHashData(const void* data_p, size_t data_size, ImGuiID seed) { ImU32 crc = ~seed; const unsigned char* data = (const unsigned char*)data_p; + const unsigned char *data_end = (const unsigned char*)data_p + data_size; #ifndef IMGUI_ENABLE_SSE4_2 const ImU32* crc32_lut = GCrc32LookupTable; - while (data_size-- != 0) + while (data < data_end) crc = (crc >> 8) ^ crc32_lut[(crc & 0xFF) ^ *data++]; return ~crc; #else - while (data_size-- != 0) + while (data + 4 <= data_end) + { + crc = _mm_crc32_u32(crc, *(ImU32*)data); + data += 4; + } + while (data < data_end) crc = _mm_crc32_u8(crc, *data++); return ~crc; #endif