From 15d58b638a1e42f4cd9da13848061b3d267ca2c5 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Sun, 27 Jun 2004 22:51:36 +0000 Subject: [PATCH] Implement InstCombine/add.ll:test21 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@14443 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/InstructionCombining.cpp | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 826e2c765e7..28e2eec0b41 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -1520,10 +1520,15 @@ Instruction *InstCombiner::visitSetCondInst(BinaryOperator &I) { if (BinaryOperator *BO = dyn_cast(Op0)) { switch (BO->getOpcode()) { case Instruction::Add: - if (CI->isNullValue()) { + // Replace ((add A, B) != C) with (A != C-B) if B & C are constants. + if (ConstantInt *BOp1C = dyn_cast(BO->getOperand(1))) { + return new SetCondInst(I.getOpcode(), BO->getOperand(0), + ConstantExpr::getSub(CI, BOp1C)); + } else if (CI->isNullValue()) { // Replace ((add A, B) != 0) with (A != -B) if A or B is // efficiently invertible, or if the add has just this one use. Value *BOp0 = BO->getOperand(0), *BOp1 = BO->getOperand(1); + if (Value *NegVal = dyn_castNegVal(BOp1)) return new SetCondInst(I.getOpcode(), BOp0, NegVal); else if (Value *NegVal = dyn_castNegVal(BOp0)) -- 2.34.1