[llvm-commits] [llvm] r53454 - /llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp

[Nick Lewycky]

Author: nicholas
Date: Fri Jul 11 03:16:26 2008
New Revision: 53454

URL: http://llvm.org/viewvc/llvm-project?rev=53454&view=rev
Log:
Document 'mask' in this calculation.

Modified:
    llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp?rev=53454&r1=53453&r2=53454&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Fri Jul 11 03:16:26 2008
@@ -5498,6 +5498,7 @@
         case Instruction::Mul:
           if (ConstantInt *CI = dyn_cast<ConstantInt>(Op0I->getOperand(1))) {
             // a * Cst icmp eq/ne b * Cst --> a & Mask icmp b & Mask
+            // Mask = -1 >> count-trailing-zeros(Cst).
             if (!CI->isZero() && !CI->isOne()) {
               const APInt &AP = CI->getValue();
               ConstantInt *Mask = ConstantInt::get(