Don't try to use SSE4.2 CRC intrinsics under Emscripten #8213
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A quick update - actually it's just the CRC comparison functions that aren't available (see https://emscripten.org/docs/porting/simd.html#id11), so this PR now only disables those under Emscripten, preserving any other use of SSE. The affected intrinsics are only |
slowriot
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Could it be reworked as a single IMGUI_ENABLE_SSE4_2_CRC defined in imgui_internal.h below IMGUI_ENABLE_SSE4_2 ? thank you! |
I have reworked your change as 2671f68 |
Thanks! |
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A very simple change to avoid enabling SSE4 under Emscripten.
This is a workaround, as the latest changes in this WIP branch don't work with Emscripten when SSE4.2 is enabled.
It is possible to build Emscripten projects with SSE4.2 (see https://emscripten.org/docs/porting/simd.html) by passing flags
-msse4.2and-msimd128, which will define__SSE4_2__. However, symbols used here such as_mm_crc32_u32are not available. Instead, Emscripten exposes a different set of WebAssembly SIMD intrinsics.This PR is just a workaround for now - an ideal solution would be to have
#ifdef EMSCRIPTENbranches for each place that uses SIMD intrinsics, and provide WASM intrinsic equivalent in those places, as described in the article above.