Index: llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp =================================================================== --- llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp +++ llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.cpp @@ -2378,9 +2378,7 @@ } // If all incoming values are sign-/zero-extended, - // the output of AND, OR, ISEL or PHI is also sign-/zero-extended. - case PPC::AND: - case PPC::AND8: + // the output of OR, ISEL or PHI is also sign-/zero-extended. case PPC::OR: case PPC::OR8: case PPC::ISEL: @@ -2411,6 +2409,36 @@ return true; } + // If at least one of the incoming values of an AND is zero extended + // then the output is also zero-extended. If both of the incoming values + // are sign-extended then the output is also sign extended. + case PPC::AND: + case PPC::AND8: { + if (Depth >= MAX_DEPTH) + return false; + + assert(MI.getOperand(1).isReg() && MI.getOperand(2).isReg()); + + unsigned SrcReg1 = MI.getOperand(1).getReg(); + unsigned SrcReg2 = MI.getOperand(2).getReg(); + + if (!TargetRegisterInfo::isVirtualRegister(SrcReg1) || + !TargetRegisterInfo::isVirtualRegister(SrcReg2)) + return false; + + const MachineInstr *MISrc1 = MRI->getVRegDef(SrcReg1); + const MachineInstr *MISrc2 = MRI->getVRegDef(SrcReg2); + if (!MISrc1 || !MISrc2) + return false; + + if(SignExt) + return isSignOrZeroExtended(*MISrc1, SignExt, Depth+1) && + isSignOrZeroExtended(*MISrc2, SignExt, Depth+1); + else + return isSignOrZeroExtended(*MISrc1, SignExt, Depth+1) || + isSignOrZeroExtended(*MISrc2, SignExt, Depth+1); + } + default: break; } Index: llvm/trunk/test/CodeGen/PowerPC/zext-and-cmp.ll =================================================================== --- llvm/trunk/test/CodeGen/PowerPC/zext-and-cmp.ll +++ llvm/trunk/test/CodeGen/PowerPC/zext-and-cmp.ll @@ -0,0 +1,33 @@ +; RUN: llc -verify-machineinstrs -mtriple=powerpc64le-unknown-linux-gnu < %s | FileCheck %s + +; Test that we recognize that an 'and' instruction that feeds a comparison +; to zero can be simplifed by using the record form when one of its operands +; is known to be zero extended. + +@k = common local_unnamed_addr global i32 0, align 4 + +; Function Attrs: norecurse nounwind +define signext i32 @cmplwi(i32* nocapture readonly %p, i32* nocapture readonly %q, i32 signext %j, i32 signext %r10) { +entry: + %0 = load i32, i32* %q, align 4 + %shl = shl i32 %0, %j + %1 = load i32, i32* %p, align 4 + %and = and i32 %shl, %r10 + %and1 = and i32 %and, %1 + %tobool = icmp eq i32 %and1, 0 + br i1 %tobool, label %cleanup, label %if.then + +if.then: + store i32 %j, i32* @k, align 4 + br label %cleanup + +cleanup: + %retval.0 = phi i32 [ 0, %if.then ], [ 1, %entry ] + ret i32 %retval.0 +} + +; CHECK-LABEL: cmplwi: +; CHECK: lwz [[T1:[0-9]+]], 0(3) +; CHECK: and. {{[0-9]+}}, {{[0-9]+}}, [[T1]] +; CHECK-NOT: cmplwi +; CHECK-NEXT: beq 0,