[clang] [Driver] Clean up fp-contract handling in clang driver (PR #91271)

[Andy Kaylor via cfe-commits]

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@@ -2893,7 +2915,6 @@ static void RenderFloatingPointOptions(const ToolChain &TC, const Driver &D,
       AssociativeMath = false;
       ReciprocalMath = false;
       SignedZeros = true;
-      FPContract = "on";
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andykaylor wrote:

It was unnecessary. Only one of the three fp-models sets FPContract to "on" and that's happening explicitly below. The code here is setting everything to what it would be for fp-model=precise and then resetting it immediately if we're handling -ffp-model=fast. Except for the FPContract state, these are right for fp-model strict as well.

https://github.com/llvm/llvm-project/pull/91271