[Support] Fix llvm::xxh3_128bits for win 32 builds

[dstutt]

#95863 caused build failures for Win32 builds.
This change includes the necessary include to fix it.

[llvmbot]

@llvm/pr-subscribers-llvm-support

Author: David Stuttard (dstutt)

Changes

#95863 caused build failures for Win32 builds.
This change includes the necessary include to fix it.

---

Full diff: https://github.com/llvm/llvm-project/pull/96891.diff

1 Files Affected:

• (modified) llvm/lib/Support/xxhash.cpp (+3)

diff --git a/llvm/lib/Support/xxhash.cpp b/llvm/lib/Support/xxhash.cpp
index a0803297555ce..8e1763809bf01 100644
--- a/llvm/lib/Support/xxhash.cpp
+++ b/llvm/lib/Support/xxhash.cpp
@@ -46,6 +46,9 @@
 #include "llvm/Support/Endian.h"
 
 #include <stdlib.h>
+#if defined(_MSC_VER) && defined(_M_IX86)
+#include <intrin.h>
+#endif
 
 using namespace llvm;
 using namespace support;

[dstutt]

I'm not sure why this only affected win32 for us - but including the header resolved the problem.

[MaskRay]

Can you edit the first comment (will be used as the commit message) to say that __emulu needs <intrin.h>`?

Upstream xxhash has a lot of code like this. Some are obviously unnecessary, but retained to work around certain very old compilers. Our simplified xxhash.cpp shouldn't have such workarounds.

[MaskRay]

Actually, I think we should remove __emulu: 96931

[dstutt]

Closing in favour of #96931