From e3152e54b5e92ef4bc29b3d8c5923893d31617ab Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Wed, 20 Sep 2006 06:41:35 +0000 Subject: [PATCH] Compile: int test3(int a, int b) { return (a < 0) ? a : 0; } to: _test3: srawi r2, r3, 31 and r3, r2, r3 blr instead of: _test3: cmpwi cr0, r3, 1 li r2, 0 blt cr0, LBB2_2 ;entry LBB2_1: ;entry mr r3, r2 LBB2_2: ;entry blr This implements: PowerPC/select_lt0.ll:seli32_a_a git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30517 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index bcbac950f4a..43028a80c2e 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -3168,7 +3168,6 @@ SDOperand DAGCombiner::SimplifySelectCC(SDOperand N0, SDOperand N1, ISD::CondCode CC) { MVT::ValueType VT = N2.getValueType(); - //ConstantSDNode *N0C = dyn_cast(N0.Val); ConstantSDNode *N1C = dyn_cast(N1.Val); ConstantSDNode *N2C = dyn_cast(N2.Val); ConstantSDNode *N3C = dyn_cast(N3.Val); @@ -3204,9 +3203,11 @@ SDOperand DAGCombiner::SimplifySelectCC(SDOperand N0, SDOperand N1, // Check to see if we can perform the "gzip trick", transforming // select_cc setlt X, 0, A, 0 -> and (sra X, size(X)-1), A - if (N1C && N1C->isNullValue() && N3C && N3C->isNullValue() && + if (N1C && N3C && N3C->isNullValue() && CC == ISD::SETLT && MVT::isInteger(N0.getValueType()) && - MVT::isInteger(N2.getValueType()) && CC == ISD::SETLT) { + MVT::isInteger(N2.getValueType()) && + (N1C->isNullValue() || // (a < 0) ? b : 0 + (N1C->getValue() == 1 && N0 == N2))) { // (a < 1) ? a : 0 MVT::ValueType XType = N0.getValueType(); MVT::ValueType AType = N2.getValueType(); if (XType >= AType) {