Convert sqrt functions into sqrt instructions when -ffast-math is in effect.

When -ffast-math is in effect (on Linux, at least), clang defines
__FINITE_MATH_ONLY__ > 0 when including <math.h>. This causes the
preprocessor to include <bits/math-finite.h>, which renames the sqrt functions.
For instance, "sqrt" is renamed as "__sqrt_finite". 

This patch adds the 3 new names in such a way that they will be treated
as equivalent to their respective original names.

llvm-svn: 182739

1 files changed, 3 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index aae11794eb0..f6867840aee 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -5562,6 +5562,9 @@ void SelectionDAGBuilder::visitCall(const CallInst &I) {
       case LibFunc::sqrt:
       case LibFunc::sqrtf:
       case LibFunc::sqrtl:
+      case LibFunc::sqrt_finite:
+      case LibFunc::sqrtf_finite:
+      case LibFunc::sqrtl_finite:
         if (visitUnaryFloatCall(I, ISD::FSQRT))
           return;
         break;