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-rw-r--r--llvm/include/llvm/CodeGen/LiveIntervalAnalysis.h4
-rw-r--r--llvm/lib/CodeGen/LiveIntervalAnalysis.cpp11
-rw-r--r--llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp39
-rw-r--r--llvm/test/CodeGen/X86/2009-02-08-CoalescerBug.ll22
4 files changed, 60 insertions, 16 deletions
diff --git a/llvm/include/llvm/CodeGen/LiveIntervalAnalysis.h b/llvm/include/llvm/CodeGen/LiveIntervalAnalysis.h
index b87214f5e2c5..aec72858c832 100644
--- a/llvm/include/llvm/CodeGen/LiveIntervalAnalysis.h
+++ b/llvm/include/llvm/CodeGen/LiveIntervalAnalysis.h
@@ -282,6 +282,10 @@ namespace llvm {
I = r2iMap_.insert(std::make_pair(reg, createInterval(reg))).first;
return *I->second;
}
+
+ /// dupInterval - Duplicate a live interval. The caller is responsible for
+ /// managing the allocated memory.
+ LiveInterval *dupInterval(LiveInterval *li);
/// addLiveRangeToEndOfBlock - Given a register and an instruction,
/// adds a live range from that instruction to the end of its MBB.
diff --git a/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp b/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp
index 8e8e8ff6d0ca..985a3fa16342 100644
--- a/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -824,11 +824,18 @@ bool LiveIntervals::findReachableMBBs(unsigned Start, unsigned End,
}
LiveInterval* LiveIntervals::createInterval(unsigned reg) {
- float Weight = TargetRegisterInfo::isPhysicalRegister(reg) ?
- HUGE_VALF : 0.0F;
+ float Weight = TargetRegisterInfo::isPhysicalRegister(reg) ? HUGE_VALF : 0.0F;
return new LiveInterval(reg, Weight);
}
+/// dupInterval - Duplicate a live interval. The caller is responsible for
+/// managing the allocated memory.
+LiveInterval* LiveIntervals::dupInterval(LiveInterval *li) {
+ LiveInterval *NewLI = createInterval(li->reg);
+ NewLI->Copy(*li, getVNInfoAllocator());
+ return NewLI;
+}
+
/// getVNInfoSourceReg - Helper function that parses the specified VNInfo
/// copy field and returns the source register that defines it.
unsigned LiveIntervals::getVNInfoSourceReg(const VNInfo *VNI) const {
diff --git a/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp b/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp
index f3ffc69cccbe..8aec579a81a5 100644
--- a/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -1322,6 +1322,15 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
DOUT << " and "; DstInt.print(DOUT, tri_);
DOUT << ": ";
+ // Save a copy of the virtual register live interval. We'll manually
+ // merge this into the "real" physical register live interval this is
+ // coalesced with.
+ LiveInterval *SavedLI = 0;
+ if (RealDstReg)
+ SavedLI = li_->dupInterval(&SrcInt);
+ else if (RealSrcReg)
+ SavedLI = li_->dupInterval(&DstInt);
+
// Check if it is necessary to propagate "isDead" property.
if (!isExtSubReg && !isInsSubReg) {
MachineOperand *mopd = CopyMI->findRegisterDefOperand(DstReg, false);
@@ -1413,21 +1422,17 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
if (RealDstReg || RealSrcReg) {
LiveInterval &RealInt =
li_->getOrCreateInterval(RealDstReg ? RealDstReg : RealSrcReg);
- SmallSet<const VNInfo*, 4> CopiedValNos;
- for (LiveInterval::Ranges::const_iterator I = ResSrcInt->ranges.begin(),
- E = ResSrcInt->ranges.end(); I != E; ++I) {
- const LiveRange *DstLR = ResDstInt->getLiveRangeContaining(I->start);
- assert(DstLR && "Invalid joined interval!");
- const VNInfo *DstValNo = DstLR->valno;
- if (CopiedValNos.insert(DstValNo)) {
- VNInfo *ValNo = RealInt.getNextValue(DstValNo->def, DstValNo->copy,
- li_->getVNInfoAllocator());
- ValNo->hasPHIKill = DstValNo->hasPHIKill;
- RealInt.addKills(ValNo, DstValNo->kills);
- RealInt.MergeValueInAsValue(*ResDstInt, DstValNo, ValNo);
- }
+ for (LiveInterval::const_vni_iterator I = SavedLI->vni_begin(),
+ E = SavedLI->vni_end(); I != E; ++I) {
+ const VNInfo *ValNo = *I;
+ VNInfo *NewValNo = RealInt.getNextValue(ValNo->def, ValNo->copy,
+ li_->getVNInfoAllocator());
+ NewValNo->hasPHIKill = ValNo->hasPHIKill;
+ NewValNo->redefByEC = ValNo->redefByEC;
+ RealInt.addKills(NewValNo, ValNo->kills);
+ RealInt.MergeValueInAsValue(*SavedLI, ValNo, NewValNo);
}
-
+ RealInt.weight += SavedLI->weight;
DstReg = RealDstReg ? RealDstReg : RealSrcReg;
}
@@ -1497,6 +1502,12 @@ bool SimpleRegisterCoalescing::JoinCopy(CopyRec &TheCopy, bool &Again) {
// being merged.
li_->removeInterval(SrcReg);
+ // Manually deleted the live interval copy.
+ if (SavedLI) {
+ SavedLI->clear();
+ delete SavedLI;
+ }
+
if (isEmpty) {
// Now the copy is being coalesced away, the val# previously defined
// by the copy is being defined by an IMPLICIT_DEF which defines a zero
diff --git a/llvm/test/CodeGen/X86/2009-02-08-CoalescerBug.ll b/llvm/test/CodeGen/X86/2009-02-08-CoalescerBug.ll
new file mode 100644
index 000000000000..cd30c1e7e40e
--- /dev/null
+++ b/llvm/test/CodeGen/X86/2009-02-08-CoalescerBug.ll
@@ -0,0 +1,22 @@
+; RUN: llvm-as < %s | llc -march=x86
+; PR3486
+
+define i32 @foo(i8 signext %p_26) nounwind {
+entry:
+ %0 = icmp eq i8 %p_26, 0 ; <i1> [#uses=2]
+ %or.cond = or i1 false, %0 ; <i1> [#uses=2]
+ %iftmp.1.0 = zext i1 %or.cond to i16 ; <i16> [#uses=1]
+ br i1 %0, label %bb.i, label %bar.exit
+
+bb.i: ; preds = %entry
+ %1 = zext i1 %or.cond to i32 ; <i32> [#uses=1]
+ %2 = sdiv i32 %1, 0 ; <i32> [#uses=1]
+ %3 = trunc i32 %2 to i16 ; <i16> [#uses=1]
+ br label %bar.exit
+
+bar.exit: ; preds = %bb.i, %entry
+ %4 = phi i16 [ %3, %bb.i ], [ %iftmp.1.0, %entry ] ; <i16> [#uses=1]
+ %5 = trunc i16 %4 to i8 ; <i8> [#uses=1]
+ %6 = sext i8 %5 to i32 ; <i32> [#uses=1]
+ ret i32 %6
+}