Instruction::isAssociative() returns true for fmul/fadd if they are tagged "unsafe" mode.

Approved by: Eli and Michael.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168848 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 14 insertions, 0 deletions

diff --git a/lib/VMCore/Instruction.cpp b/lib/VMCore/Instruction.cpp
index 4208144cb5..d93c1d7a22 100644
--- a/lib/VMCore/Instruction.cpp
+++ b/lib/VMCore/Instruction.cpp
@@ -468,6 +468,20 @@ bool Instruction::isAssociative(unsigned Opcode) {
          Opcode == Add || Opcode == Mul;
 }
 
+bool Instruction::isAssociative() const {
+  unsigned Opcode = getOpcode();
+  if (isAssociative(Opcode))
+    return true;
+
+  switch (Opcode) {
+  case FMul:
+  case FAdd:
+    return cast<FPMathOperator>(this)->hasUnsafeAlgebra();
+  default:
+    return false;
+  }
+}
+
 /// isCommutative - Return true if the instruction is commutative:
 ///
 ///   Commutative operators satisfy: (x op y) === (y op x)