From 32ed46b36e1457b0b978cd5434cce3bdae4c914b Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Tue, 4 May 2004 15:19:33 +0000 Subject: [PATCH] Minor efficiency tweak, suggested by Patrick Meredith git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13341 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/InstructionCombining.cpp | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 138dc962532..2266a70b6e6 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -12,10 +12,10 @@ // simplification happens. // // This pass combines things like: -// %Y = add int 1, %X -// %Z = add int 1, %Y +// %Y = add int %X, 1 +// %Z = add int %Y, 1 // into: -// %Z = add int 2, %X +// %Z = add int %X, 2 // // This is a simple worklist driven algorithm. // @@ -887,7 +887,7 @@ Instruction *InstCombiner::visitRem(BinaryOperator &I) { // if so, convert to a bitwise and. if (ConstantUInt *C = dyn_cast(RHS)) if (uint64_t Val = C->getValue()) // Don't break X % 0 (divide by zero) - if (Log2(Val)) + if (!(Val & Val-1)) // Power of 2 return BinaryOperator::create(Instruction::And, I.getOperand(0), ConstantUInt::get(I.getType(), Val-1)); }