[llvm] [TLI] Add getLibFunc in TLI API that accepts an Instruction. (PR #75919)

[Paul Walker via llvm-commits]

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@@ -1149,6 +1149,22 @@ bool TargetLibraryInfoImpl::getLibFunc(const Function &FDecl,
   return isValidProtoForLibFunc(*FDecl.getFunctionType(), F, *M);
 }
 
+bool TargetLibraryInfoImpl::getLibFunc(const Instruction &I, LibFunc &F) const {
+  if (I.getOpcode() != Instruction::FRem)
+    return false;
+
+  Type *ScalarTy = I.getType()->getScalarType();
+  if (ScalarTy->isDoubleTy())
+    F = LibFunc_fmod;
+  else if (ScalarTy->isFloatTy())
+    F = LibFunc_fmodf;
+  else if (ScalarTy->isFP128Ty())
+    F = LibFunc_fmodl;
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paulwalker-arm wrote:

This is not strictly speaking true because the choice of what underlying LLVM type is used to represent a long double is target specific.  I think it's safer to drop this code.

https://github.com/llvm/llvm-project/pull/75919