[clang] clang: Add pragma clang fp reciprocal (PR #68267)

[Andy Kaylor via cfe-commits]

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@@ -1309,6 +1309,13 @@ void Sema::ActOnPragmaFPReassociate(SourceLocation Loc, bool IsEnabled) {
   CurFPFeatures = NewFPFeatures.applyOverrides(getLangOpts());
 }
 
+void Sema::ActOnPragmaFPReciprocal(SourceLocation Loc, bool IsEnabled) {
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andykaylor wrote:

There's some discussion of it here: https://reviews.llvm.org/D122155

The basic idea is that it doesn't make sense to allow value-changing optimizations while also specifying extra precision to be used for intermediate calculations.

https://github.com/llvm/llvm-project/pull/68267