If a MI uses the same register more than once, only mark one of them as 'kill'.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66363 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2009-03-08 03:58:35 +00:00
parent 8e10844ad0
commit 821b8560e7
2 changed files with 100 additions and 6 deletions

View File

@ -1317,6 +1317,23 @@ void LocalSpiller::TransferDeadness(MachineBasicBlock *MBB, unsigned CurDist,
}
}
/// hasLaterNon2AddrUse - If the MI has another use of the specified virtual
/// register later and it's not a two-address, return true. That means it's
/// safe to mark the current use at 'i' isKill.
static bool hasLaterNon2AddrUse(MachineInstr &MI, unsigned i, unsigned VirtReg){
const TargetInstrDesc &TID = MI.getDesc();
++i;
for (unsigned e = TID.getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI.getOperand(i);
if (!MO.isReg() || MO.getReg() != VirtReg)
continue;
if (TID.getOperandConstraint(i, TOI::TIED_TO) == -1)
return true;
}
return false;
}
/// rewriteMBB - Keep track of which spills are available even after the
/// register allocator is done with them. If possible, avid reloading vregs.
void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM,
@ -1581,9 +1598,7 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM,
// apply, reuse it.
bool CanReuse = true;
int ti = TID.getOperandConstraint(i, TOI::TIED_TO);
if (ti != -1 &&
MI.getOperand(ti).isReg() &&
MI.getOperand(ti).getReg() == VirtReg) {
if (ti != -1) {
// Okay, we have a two address operand. We can reuse this physreg as
// long as we are allowed to clobber the value and there isn't an
// earlier def that has already clobbered the physreg.
@ -1637,9 +1652,10 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM,
PotentialDeadStoreSlots.push_back(ReuseSlot);
}
// Assumes this is the last use. IsKill will be unset if reg is reused
// unless it's a two-address operand.
if (ti == -1)
// Mark is isKill if it's there no other uses of the same virtual
// register and it's not a two-address operand. IsKill will be
// unset if reg is reused.
if (ti == -1 && !hasLaterNon2AddrUse(MI, i, VirtReg))
MI.getOperand(i).setIsKill();
continue;
} // CanReuse

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@ -0,0 +1,78 @@
; RUN: llvm-as < %s | llc -mtriple=armv6-apple-darwin9 -mattr=+vfp2
; rdar://6653182
%struct.ggBRDF = type { i32 (...)** }
%struct.ggPoint2 = type { [2 x double] }
%struct.ggPoint3 = type { [3 x double] }
%struct.ggSpectrum = type { [8 x float] }
%struct.ggSphere = type { %struct.ggPoint3, double }
%struct.mrDiffuseAreaSphereLuminaire = type { %struct.mrSphere, %struct.ggSpectrum }
%struct.mrDiffuseCosineSphereLuminaire = type { %struct.mrDiffuseAreaSphereLuminaire }
%struct.mrSphere = type { %struct.ggBRDF, %struct.ggSphere }
declare void @llvm.memcpy.i32(i8* nocapture, i8* nocapture, i32, i32) nounwind
declare double @llvm.sqrt.f64(double) nounwind readonly
declare double @sin(double) nounwind readonly
declare double @acos(double) nounwind readonly
define i32 @_ZNK34mrDiffuseSolidAngleSphereLuminaire18selectVisiblePointERK8ggPoint3RK9ggVector3RK8ggPoint2dRS0_Rd(%struct.mrDiffuseCosineSphereLuminaire* nocapture %this, %struct.ggPoint3* nocapture %x, %struct.ggPoint3* nocapture %unnamed_arg, %struct.ggPoint2* nocapture %uv, double %unnamed_arg2, %struct.ggPoint3* nocapture %on_light, double* nocapture %invProb) nounwind {
entry:
%0 = call double @llvm.sqrt.f64(double 0.000000e+00) nounwind ; <double> [#uses=4]
%1 = fcmp ult double 0.000000e+00, %0 ; <i1> [#uses=1]
br i1 %1, label %bb3, label %bb7
bb3: ; preds = %entry
%2 = fdiv double 1.000000e+00, 0.000000e+00 ; <double> [#uses=1]
%3 = mul double 0.000000e+00, %2 ; <double> [#uses=2]
%4 = call double @llvm.sqrt.f64(double 0.000000e+00) nounwind ; <double> [#uses=1]
%5 = fdiv double 1.000000e+00, %4 ; <double> [#uses=2]
%6 = mul double %3, %5 ; <double> [#uses=2]
%7 = mul double 0.000000e+00, %5 ; <double> [#uses=2]
%8 = mul double %3, %7 ; <double> [#uses=1]
%9 = sub double %8, 0.000000e+00 ; <double> [#uses=1]
%10 = mul double 0.000000e+00, %6 ; <double> [#uses=1]
%11 = sub double 0.000000e+00, %10 ; <double> [#uses=1]
%12 = sub double -0.000000e+00, %11 ; <double> [#uses=1]
%13 = mul double %0, %0 ; <double> [#uses=2]
%14 = sub double %13, 0.000000e+00 ; <double> [#uses=1]
%15 = call double @llvm.sqrt.f64(double %14) ; <double> [#uses=1]
%16 = mul double 0.000000e+00, %15 ; <double> [#uses=1]
%17 = fdiv double %16, %0 ; <double> [#uses=1]
%18 = add double 0.000000e+00, %17 ; <double> [#uses=1]
%19 = call double @acos(double %18) nounwind readonly ; <double> [#uses=1]
%20 = load double* null, align 4 ; <double> [#uses=1]
%21 = mul double %20, 0x401921FB54442D18 ; <double> [#uses=1]
%22 = call double @sin(double %19) nounwind readonly ; <double> [#uses=2]
%23 = mul double %22, 0.000000e+00 ; <double> [#uses=2]
%24 = mul double %6, %23 ; <double> [#uses=1]
%25 = mul double %7, %23 ; <double> [#uses=1]
%26 = call double @sin(double %21) nounwind readonly ; <double> [#uses=1]
%27 = mul double %22, %26 ; <double> [#uses=2]
%28 = mul double %9, %27 ; <double> [#uses=1]
%29 = mul double %27, %12 ; <double> [#uses=1]
%30 = add double %24, %28 ; <double> [#uses=1]
%31 = add double 0.000000e+00, %29 ; <double> [#uses=1]
%32 = add double %25, 0.000000e+00 ; <double> [#uses=1]
%33 = add double %30, 0.000000e+00 ; <double> [#uses=1]
%34 = add double %31, 0.000000e+00 ; <double> [#uses=1]
%35 = add double %32, 0.000000e+00 ; <double> [#uses=1]
%36 = bitcast %struct.ggPoint3* %x to i8* ; <i8*> [#uses=1]
call void @llvm.memcpy.i32(i8* null, i8* %36, i32 24, i32 4) nounwind
store double %33, double* null, align 8
br i1 false, label %_Z20ggRaySphereIntersectRK6ggRay3RK8ggSphereddRd.exit, label %bb5.i.i.i
bb5.i.i.i: ; preds = %bb3
unreachable
_Z20ggRaySphereIntersectRK6ggRay3RK8ggSphereddRd.exit: ; preds = %bb3
%37 = sub double %13, 0.000000e+00 ; <double> [#uses=0]
%38 = sub double -0.000000e+00, %34 ; <double> [#uses=0]
%39 = sub double -0.000000e+00, %35 ; <double> [#uses=0]
ret i32 1
bb7: ; preds = %entry
ret i32 0
}