Drop the REDEF_BY_EC VNInfo flag.

A live range that has an early clobber tied redef now looks like a
normal tied redef, except the early clobber def uses the early clobber
slot.

This is enough to handle any strange interference problems.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149769 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jakob Stoklund Olesen 2012-02-04 05:51:25 +00:00
parent 7e899cbb91
commit 0aad7d274d
4 changed files with 2 additions and 51 deletions

View File

@ -43,9 +43,8 @@ namespace llvm {
private:
enum {
HAS_PHI_KILL = 1,
REDEF_BY_EC = 1 << 1,
IS_PHI_DEF = 1 << 2,
IS_UNUSED = 1 << 3
IS_PHI_DEF = 1 << 1,
IS_UNUSED = 1 << 2
};
unsigned char flags;
@ -95,17 +94,6 @@ namespace llvm {
flags &= ~HAS_PHI_KILL;
}
/// Returns true if this value is re-defined by an early clobber somewhere
/// during the live range.
bool hasRedefByEC() const { return flags & REDEF_BY_EC; }
/// Set the "redef by early clobber" flag on this value.
void setHasRedefByEC(bool hasRedef) {
if (hasRedef)
flags |= REDEF_BY_EC;
else
flags &= ~REDEF_BY_EC;
}
/// Returns true if this value is defined by a PHI instruction (or was,
/// PHI instrucions may have been eliminated).
bool isPHIDef() const { return flags & IS_PHI_DEF; }

View File

@ -642,8 +642,6 @@ void LiveInterval::print(raw_ostream &OS, const TargetRegisterInfo *TRI) const {
OS << "-phidef";
if (vni->hasPHIKill())
OS << "-phikill";
if (vni->hasRedefByEC())
OS << "-ec";
}
}
}

View File

@ -432,8 +432,6 @@ exit:
bool Extend = ValNo != 0;
if (!Extend)
ValNo = interval.getNextValue(start, VNInfoAllocator);
if (Extend && MO.isEarlyClobber())
ValNo->setHasRedefByEC(true);
LiveRange LR(start, end, ValNo);
interval.addRange(LR);
DEBUG(dbgs() << " +" << LR << '\n');

View File

@ -438,27 +438,6 @@ bool RegisterCoalescer::AdjustCopiesBackFrom(const CoalescerPair &CP,
// The live range might not exist after fun with physreg coalescing.
if (ALR == IntA.end()) return false;
VNInfo *AValNo = ALR->valno;
// If it's re-defined by an early clobber somewhere in the live range, then
// it's not safe to eliminate the copy. FIXME: This is a temporary workaround.
// See PR3149:
// 172 %ECX<def> = MOV32rr %reg1039<kill>
// 180 INLINEASM <es:subl $5,$1
// sbbl $3,$0>, 10, %EAX<def>, 14, %ECX<earlyclobber,def>, 9,
// %EAX<kill>,
// 36, <fi#0>, 1, %reg0, 0, 9, %ECX<kill>, 36, <fi#1>, 1, %reg0, 0
// 188 %EAX<def> = MOV32rr %EAX<kill>
// 196 %ECX<def> = MOV32rr %ECX<kill>
// 204 %ECX<def> = MOV32rr %ECX<kill>
// 212 %EAX<def> = MOV32rr %EAX<kill>
// 220 %EAX<def> = MOV32rr %EAX
// 228 %reg1039<def> = MOV32rr %ECX<kill>
// The early clobber operand ties ECX input to the ECX def.
//
// The live interval of ECX is represented as this:
// %reg20,inf = [46,47:1)[174,230:0) 0@174-(230) 1@46-(47)
// The coalescer has no idea there was a def in the middle of [174,230].
if (AValNo->hasRedefByEC())
return false;
// If AValNo is defined as a copy from IntB, we can potentially process this.
// Get the instruction that defines this value number.
@ -1510,10 +1489,6 @@ bool RegisterCoalescer::JoinIntervals(CoalescerPair &CP) {
if (!MI->isCopyLike()) // Src not defined by a copy?
continue;
// Never join with a register that has EarlyClobber redefs.
if (VNI->hasRedefByEC())
return false;
// Figure out the value # from the RHS.
LiveRange *lr = RHS.getLiveRangeContaining(VNI->def.getPrevSlot());
// The copy could be to an aliased physreg.
@ -1540,10 +1515,6 @@ bool RegisterCoalescer::JoinIntervals(CoalescerPair &CP) {
if (!MI->isCopyLike()) // Src not defined by a copy?
continue;
// Never join with a register that has EarlyClobber redefs.
if (VNI->hasRedefByEC())
return false;
// Figure out the value # from the LHS.
LiveRange *lr = LHS.getLiveRangeContaining(VNI->def.getPrevSlot());
// The copy could be to an aliased physreg.
@ -1624,10 +1595,6 @@ bool RegisterCoalescer::JoinIntervals(CoalescerPair &CP) {
if (LHSValNoAssignments[I->valno->id] !=
RHSValNoAssignments[J->valno->id])
return false;
// If it's re-defined by an early clobber somewhere in the live range,
// then conservatively abort coalescing.
if (NewVNInfo[LHSValNoAssignments[I->valno->id]]->hasRedefByEC())
return false;
}
if (I->end < J->end)