[llvm] [CodeGen] Provide `MachineFunction::hasUnsafeFPMath` (PR #127488)

[Artem Belevich via llvm-commits]

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@@ -699,6 +699,11 @@ bool MachineFunction::needsFrameMoves() const {
          !F.getParent()->debug_compile_units().empty();
 }
 
+/// True if function attribute unsafe-fp-math is true.
+bool MachineFunction::hasUnsafeFPMath() const {
+  return F.getFnAttribute("unsafe-fp-math").getValueAsBool();
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Artem-B wrote:

Does `--enable-unsafe-fp-math` currently set `unsafe-fp-math` on all functions?
If it does not, then the change will likely affect performance, as unsafe math will only enable unsafe optimizations in explicitly marked functions only. Ignoring global `Options.UnsafeFPMath` may not be the best idea.

> break some tests.
Can you elaborate on which tests failed and how. It's possible that it's those tests that should be fixed, instead.



https://github.com/llvm/llvm-project/pull/127488