[clang] Honor pragmas with -ffp-contract=fast, depecate fast-honor-pragmas (PR #105746)

[Eli Friedman via cfe-commits]

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@@ -348,20 +348,8 @@ static bool initTargetOptions(DiagnosticsEngine &Diags,
           .Default(llvm::FloatABI::Default);
 
   // Set FP fusion mode.
-  switch (LangOpts.getDefaultFPContractMode()) {
-  case LangOptions::FPM_Off:
-    // Preserve any contraction performed by the front-end.  (Strict performs
-    // splitting of the muladd intrinsic in the backend.)
-    Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
-    break;
-  case LangOptions::FPM_On:
-  case LangOptions::FPM_FastHonorPragmas:
-    Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
-    break;
-  case LangOptions::FPM_Fast:
-    Options.AllowFPOpFusion = llvm::FPOpFusion::Fast;
-    break;
-  }
+  // All allowed fusion is indicated in the IR.
+  Options.AllowFPOpFusion = llvm::FPOpFusion::Standard;
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efriedma-quic wrote:

This is redundant, I think; Standard is the default anyway.

https://github.com/llvm/llvm-project/pull/105746