diff options
Diffstat (limited to 'lib/CodeGen')
| -rw-r--r-- | lib/CodeGen/LiveIntervalAnalysis.cpp | 16 | ||||
| -rw-r--r-- | lib/CodeGen/SimpleRegisterCoalescing.cpp | 20 |
2 files changed, 29 insertions, 7 deletions
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp index 52b57d6d2e..1900c1a4d7 100644 --- a/lib/CodeGen/LiveIntervalAnalysis.cpp +++ b/lib/CodeGen/LiveIntervalAnalysis.cpp @@ -360,6 +360,7 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb, mi->getOpcode() == TargetInstrInfo::INSERT_SUBREG || tii_->isMoveInstr(*mi, SrcReg, DstReg)) CopyMI = mi; + // Earlyclobbers move back one. ValNo = interval.getNextValue(defIndex, CopyMI, VNInfoAllocator); assert(ValNo->id == 0 && "First value in interval is not 0?"); @@ -435,9 +436,8 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb, assert(interval.containsOneValue()); unsigned DefIndex = getDefIndex(interval.getValNumInfo(0)->def); unsigned RedefIndex = getDefIndex(MIIdx); - // Earlyclobbers move back one. - if (MO.isEarlyClobber()) - RedefIndex = getUseIndex(MIIdx); + // It cannot be an early clobber MO. + assert(!MO.isEarlyClobber() && "Unexpected early clobber!"); const LiveRange *OldLR = interval.getLiveRangeContaining(RedefIndex-1); VNInfo *OldValNo = OldLR->valno; @@ -505,9 +505,8 @@ void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb, // live until the end of the block. We've already taken care of the // rest of the live range. unsigned defIndex = getDefIndex(MIIdx); - // Earlyclobbers move back one. - if (MO.isEarlyClobber()) - defIndex = getUseIndex(MIIdx); + // It cannot be an early clobber MO. + assert(!MO.isEarlyClobber() && "Unexpected early clobber!"); VNInfo *ValNo; MachineInstr *CopyMI = NULL; @@ -592,8 +591,11 @@ exit: // Already exists? Extend old live interval. LiveInterval::iterator OldLR = interval.FindLiveRangeContaining(start); - VNInfo *ValNo = (OldLR != interval.end()) + bool Extend = OldLR != interval.end(); + VNInfo *ValNo = Extend ? OldLR->valno : interval.getNextValue(start, CopyMI, VNInfoAllocator); + if (MO.isEarlyClobber() && Extend) + ValNo->redefByEC = true; LiveRange LR(start, end, ValNo); interval.addRange(LR); interval.addKill(LR.valno, end); diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp index 41022a6e26..cfac82613f 100644 --- a/lib/CodeGen/SimpleRegisterCoalescing.cpp +++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp @@ -119,6 +119,26 @@ bool SimpleRegisterCoalescing::AdjustCopiesBackFrom(LiveInterval &IntA, if (ALR == IntA.end()) // Should never happen! 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->redefByEC) + return false; // If AValNo is defined as a copy from IntB, we can potentially process this. // Get the instruction that defines this value number. |