[PATCH] D142178: [X86] Change precision control to FP80 during u64->fp32 conversion on Windows.

Thu Feb 2 10:44:50 PST 2023

icedrocket added inline comments.

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Comment at: llvm/test/CodeGen/X86/uint64-to-float.ll:64
+; X86-WIN-NEXT:    fldcw {{[0-9]+}}(%esp)
+; X86-WIN-NEXT:    fadds __real at 5f80000000000000(,%eax,4)
+; X86-WIN-NEXT:    fldcw {{[0-9]+}}(%esp)
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craig.topper wrote:
> icedrocket wrote:
> > I checked the assembly generated by clang and it seems that fadds is split into fld and fadd.
> That's weird. Do you have a C file you can share?
The file is same as the summary's code in D141074. I think that there is no actual `fadds` instruction in x87 and end up split into two instructions.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D142178/new/

https://reviews.llvm.org/D142178