From: Nate Begeman Date: Wed, 6 Apr 2005 06:44:57 +0000 (+0000) Subject: Fixed version of optimized integer divide is now fixed. Calculate the X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=27b4c23b8085563158d1b6a4e8892fad999b579c;p=oota-llvm.git Fixed version of optimized integer divide is now fixed. Calculate the quotient, not the remainder. Also, make sure to remove the old div operand from the ExprMap and let SelectExpr insert the new one. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21111 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/Target/PowerPC/PPCISelPattern.cpp b/lib/Target/PowerPC/PPCISelPattern.cpp index 465a9bccf1d..3ece1b29f9b 100644 --- a/lib/Target/PowerPC/PPCISelPattern.cpp +++ b/lib/Target/PowerPC/PPCISelPattern.cpp @@ -551,7 +551,7 @@ static unsigned getImmediateForOpcode(SDOperand N, unsigned Opcode, if (v <= -2 || v >= 2) { return 4; } break; case ISD::UDIV: - if (v != 0) { return 4; } + if (v > 1) { return 4; } break; } return 0; @@ -711,10 +711,7 @@ SDOperand ISel::BuildSDIVSequence(SDOperand N) { // Extract the sign bit and add it to the quotient SDOperand T = ISelDAG->getNode(ISD::SRL, MVT::i32, Q, ISelDAG->getConstant(31, MVT::i32)); - Q = ISelDAG->getNode(ISD::ADD, MVT::i32, Q, T); - // Compute the remainder - T = ISelDAG->getNode(ISD::MUL, MVT::i32, Q, N.getOperand(1)); - return ISelDAG->getNode(ISD::SUB, MVT::i32, N.getOperand(0), T); + return ISelDAG->getNode(ISD::ADD, MVT::i32, Q, T); } /// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant, @@ -739,9 +736,7 @@ SDOperand ISel::BuildUDIVSequence(SDOperand N) { Q = ISelDAG->getNode(ISD::SRL, MVT::i32, NPQ, ISelDAG->getConstant(magics.s-1, MVT::i32)); } - // Compute the remainder - SDOperand T = ISelDAG->getNode(ISD::MUL, MVT::i32, Q, N.getOperand(1)); - return ISelDAG->getNode(ISD::SUB, MVT::i32, N.getOperand(0), T); + return Q; } /// getGlobalBaseReg - Output the instructions required to put the @@ -1601,11 +1596,12 @@ unsigned ISel::SelectExpr(SDOperand N) { return Result; // If this is a divide by constant, we can emit code using some magic // constants to implement it as a multiply instead. - //case 4: - // if (opcode == ISD::SDIV) - // return SelectExpr(BuildSDIVSequence(N)); - // else - // return SelectExpr(BuildUDIVSequence(N)); + case 4: + ExprMap.erase(N); + if (opcode == ISD::SDIV) + return SelectExpr(BuildSDIVSequence(N)); + else + return SelectExpr(BuildUDIVSequence(N)); } Tmp1 = SelectExpr(N.getOperand(0)); Tmp2 = SelectExpr(N.getOperand(1));