[llvm] [llvm] Change `fp128` lowering to use `f128` functions by default (PR #76558)

[Nikita Popov via llvm-commits]

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@@ -2306,6 +2306,43 @@ ExceptionHandling Triple::getDefaultExceptionHandling() const {
   return ExceptionHandling::None;
 }
 
+bool Triple::f128LibmShouldUseLongDouble() const {
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nikic wrote:

I would formulate this in terms of `Triple::getDefaultLongDoubleWidth()` and add a consistency check in
https://github.com/llvm/llvm-project/blob/b6313b381ac0e83012ea11b4549cd8cb39b686d2/clang/lib/CodeGen/CodeGenModule.cpp#L335 to ensure it agrees with clang.

https://github.com/llvm/llvm-project/pull/76558