[llvm] r289153 - [InstSimplify] Add "X / 1.0" to SimplifyFDivInst.

[Zia Ansari via llvm-commits]

Author: zansari
Date: Thu Dec  8 17:27:40 2016
New Revision: 289153

URL: http://llvm.org/viewvc/llvm-project?rev=289153&view=rev
Log:
[InstSimplify] Add "X / 1.0" to SimplifyFDivInst.

Differential Revision: https://reviews.llvm.org/D27587

Modified:
    llvm/trunk/lib/Analysis/InstructionSimplify.cpp
    llvm/trunk/test/Transforms/InstSimplify/floating-point-arithmetic.ll

Modified: llvm/trunk/lib/Analysis/InstructionSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/InstructionSimplify.cpp?rev=289153&r1=289152&r2=289153&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/InstructionSimplify.cpp (original)
+++ llvm/trunk/lib/Analysis/InstructionSimplify.cpp Thu Dec  8 17:27:40 2016
@@ -1127,6 +1127,10 @@ static Value *SimplifyFDivInst(Value *Op
   if (match(Op1, m_Undef()))
     return Op1;
 
+  // X / 1.0 -> X
+  if (match(Op1, m_FPOne()))
+    return Op0;
+
   // 0 / X -> 0
   // Requires that NaNs are off (X could be zero) and signed zeroes are
   // ignored (X could be positive or negative, so the output sign is unknown).
@@ -4093,6 +4097,8 @@ static Value *SimplifyFPBinOp(unsigned O
     return SimplifyFSubInst(LHS, RHS, FMF, Q, MaxRecurse);
   case Instruction::FMul:
     return SimplifyFMulInst(LHS, RHS, FMF, Q, MaxRecurse);
+  case Instruction::FDiv:
+    return SimplifyFDivInst(LHS, RHS, FMF, Q, MaxRecurse);
   default:
     return SimplifyBinOp(Opcode, LHS, RHS, Q, MaxRecurse);
   }

Modified: llvm/trunk/test/Transforms/InstSimplify/floating-point-arithmetic.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstSimplify/floating-point-arithmetic.ll?rev=289153&r1=289152&r2=289153&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstSimplify/floating-point-arithmetic.ll (original)
+++ llvm/trunk/test/Transforms/InstSimplify/floating-point-arithmetic.ll Thu Dec  8 17:27:40 2016
@@ -62,12 +62,10 @@ define double @fmul_X_1(double %a) {
   ret double %b
 }
 
-; FIXME:
 ; fdiv X, 1.0 ==> X
 define float @fdiv_x_1(float %a) {
 ; CHECK-LABEL: @fdiv_x_1(
-; CHECK-NEXT:    [[RET:%.*]] = fdiv float %a, 1.000000e+00
-; CHECK-NEXT:    ret float [[RET]]
+; CHECK-NEXT:    ret float %a
 ;
   %ret = fdiv float %a, 1.0
   ret float %ret