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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - ms: _byteswap_ulong etc intrinsic generate calls"
href="https://bugs.llvm.org/show_bug.cgi?id=49040">49040</a>
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<th>Summary</th>
<td>ms: _byteswap_ulong etc intrinsic generate calls
</td>
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<th>Product</th>
<td>clang
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<th>Version</th>
<td>unspecified
</td>
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<th>Hardware</th>
<td>PC
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<th>OS</th>
<td>Linux
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>enhancement
</td>
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>Headers
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>nicolasweber@gmx.de
</td>
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<th>CC</th>
<td>craig.topper@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
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<p>
<div>
<pre>$ cat bswap.cc
#include <stdint.h>
#include <intrin.h>
int32_t ByteSwap(uint32_t x) {
return _byteswap_ulong(x);
}
$ out/gn/bin/clang-cl /FA /c bswap.cc /O2 /winsysroot
~/src/chrome/src/third_party/depot_tools/win_toolchain/vs_files/782813b4eb/
$ cat bswap.asm
...
"?ByteSwap@@YAHI@Z": # @"?ByteSwap@@YAHI@Z"
# %bb.0: # %entry
jmp _byteswap_ulong # TAILCALL
# -- End function
Compare to <a href="https://godbolt.org/z/97YjTT">https://godbolt.org/z/97YjTT</a> in MSVC.
Our clang/lib/Headers/intrin.h only has a declaration for these functions in
arm64 mode for some reason. So how does this even build? => Windows
Kits/10/Include/10.0.19041.0/ucrt/stdlib.h declares these too.
So I guess we should put these in intrin.h, with an inline definition?</pre>
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