commit a4f445b28c3c55949e6be72514f4225c95dc87a9
author Chris Lattner <sabre@nondot.org> Mon Mar 10 23:23:04 2003 +0000
committer Chris Lattner <sabre@nondot.org> Mon Mar 10 23:23:04 2003 +0000
tree 046b318be80530803dfa7942e0cd859332f4cdcc
parent 533741a76416f2201252d0210babc64b2a7c904a

Implement: -A*-B == A*B


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5740 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Scalar/InstructionCombining.cpp

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 79a551f..067a884 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -342,6 +342,10 @@
     }
   }
 
+  if (Value *Op0v = dyn_castNegVal(Op0))     // -X * -Y = X*Y
+    if (Value *Op1v = dyn_castNegVal(I.getOperand(1)))
+      return BinaryOperator::create(Instruction::Mul, Op0v, Op1v);
+
   return Changed ? &I : 0;
 }