[llvm-commits] [llvm] r157135 - in /llvm/trunk: lib/CodeGen/LiveRangeEdit.cpp lib/CodeGen/RegisterCoalescer.cpp test/CodeGen/X86/2012-05-19-CoalescerCrash.ll
Jakob Stoklund Olesen
stoklund at 2pi.dk
Sat May 19 16:35:00 PDT 2012
Author: stoklund
Date: Sat May 19 18:34:59 2012
New Revision: 157135
URL: http://llvm.org/viewvc/llvm-project?rev=157135&view=rev
Log:
Fix 12892.
Dead code elimination during coalescing could cause a virtual register
to be split into connected components. The following rewriting would be
confused about the already joined copies present in the code, but
without a corresponding value number in the live range.
Erase all joined copies instantly when joining intervals such that the
MI and LiveInterval representations are always in sync.
Added:
llvm/trunk/test/CodeGen/X86/2012-05-19-CoalescerCrash.ll
Modified:
llvm/trunk/lib/CodeGen/LiveRangeEdit.cpp
llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp
Modified: llvm/trunk/lib/CodeGen/LiveRangeEdit.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/LiveRangeEdit.cpp?rev=157135&r1=157134&r2=157135&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/LiveRangeEdit.cpp (original)
+++ llvm/trunk/lib/CodeGen/LiveRangeEdit.cpp Sat May 19 18:34:59 2012
@@ -308,6 +308,10 @@
TheDelegate->LRE_DidCloneVirtReg(Dups.back()->reg, LI->reg);
}
ConEQ.Distribute(&Dups[0], MRI);
+ DEBUG({
+ for (unsigned i = 0; i != NumComp; ++i)
+ dbgs() << '\t' << *Dups[i] << '\n';
+ });
}
}
Modified: llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp?rev=157135&r1=157134&r2=157135&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp Sat May 19 18:34:59 2012
@@ -1081,9 +1081,10 @@
if (!CP.isPhys() && RegClassInfo.isProperSubClass(CP.getNewRC()))
InflateRegs.push_back(CP.getDstReg());
- // Remember to delete the copy instruction.
- LIS->RemoveMachineInstrFromMaps(CopyMI);
- CopyMI->eraseFromParent();
+ // CopyMI has been erased by joinIntervals at this point. Remove it from
+ // ErasedInstrs since copyCoalesceWorkList() won't add a successful join back
+ // to the work list. This keeps ErasedInstrs from growing needlessly.
+ ErasedInstrs.erase(CopyMI);
// Rewrite all SrcReg operands to DstReg.
// Also update DstReg operands to include DstIdx if it is set.
@@ -1285,6 +1286,7 @@
SmallVector<VNInfo*, 16> NewVNInfo;
SmallVector<MachineInstr*, 8> DupCopies;
+ SmallVector<MachineInstr*, 8> DeadCopies;
LiveInterval &LHS = LIS->getOrCreateInterval(CP.getDstReg());
DEBUG({ dbgs() << "\t\tLHS = "; LHS.print(dbgs(), TRI); dbgs() << "\n"; });
@@ -1313,6 +1315,7 @@
continue;
LHSValsDefinedFromRHS[VNI] = lr->valno;
+ DeadCopies.push_back(MI);
}
// Loop over the value numbers of the RHS, seeing if any are defined from
@@ -1339,6 +1342,7 @@
continue;
RHSValsDefinedFromLHS[VNI] = lr->valno;
+ DeadCopies.push_back(MI);
}
LHSValNoAssignments.resize(LHS.getNumValNums(), -1);
@@ -1438,6 +1442,17 @@
if (RHSValNoAssignments.empty())
RHSValNoAssignments.push_back(-1);
+ // Now erase all the redundant copies.
+ for (unsigned i = 0, e = DeadCopies.size(); i != e; ++i) {
+ MachineInstr *MI = DeadCopies[i];
+ DEBUG(dbgs() << "\t\terased:\t" << LIS->getInstructionIndex(MI)
+ << '\t' << *MI);
+ if (!ErasedInstrs.insert(MI))
+ continue;
+ LIS->RemoveMachineInstrFromMaps(MI);
+ MI->eraseFromParent();
+ }
+
SmallVector<unsigned, 8> SourceRegisters;
for (SmallVector<MachineInstr*, 8>::iterator I = DupCopies.begin(),
E = DupCopies.end(); I != E; ++I) {
@@ -1451,7 +1466,8 @@
// A = X
unsigned Src = MI->getOperand(1).getReg();
SourceRegisters.push_back(Src);
- ErasedInstrs.insert(MI);
+ if (!ErasedInstrs.insert(MI))
+ continue;
LIS->RemoveMachineInstrFromMaps(MI);
MI->eraseFromParent();
}
Added: llvm/trunk/test/CodeGen/X86/2012-05-19-CoalescerCrash.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/2012-05-19-CoalescerCrash.ll?rev=157135&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/2012-05-19-CoalescerCrash.ll (added)
+++ llvm/trunk/test/CodeGen/X86/2012-05-19-CoalescerCrash.ll Sat May 19 18:34:59 2012
@@ -0,0 +1,122 @@
+; RUN: llc < %s -verify-coalescing
+; PR12892
+;
+; Dead code elimination during coalesing causes a live range to split into two
+; virtual registers. Stale identity copies that had already been joined were
+; interfering with the liveness computations.
+
+target triple = "i386-pc-linux-gnu"
+
+define void @_ZN4llvm17AsmMatcherEmitter3runERNS_11raw_ostreamE() align 2 {
+ invoke void @_ZNK4llvm13CodeGenTarget12getAsmParserEv()
+ to label %1 unwind label %5
+
+; <label>:1 ; preds = %0
+ invoke void @_ZNK4llvm6Record16getValueAsStringENS_9StringRefE()
+ to label %4 unwind label %2
+
+; <label>:2 ; preds = %1
+ %3 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
+ cleanup
+ unreachable
+
+; <label>:4 ; preds = %1
+ invoke void @_ZN4llvm18isCurrentDebugTypeEPKc()
+ to label %12 unwind label %7
+
+; <label>:5 ; preds = %0
+ %6 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
+ cleanup
+ br label %33
+
+; <label>:7 ; preds = %4
+ %8 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
+ cleanup
+ br label %9
+
+; <label>:9 ; preds = %28, %7
+ %10 = phi { i8*, i32 } [ %29, %28 ], [ %8, %7 ]
+ %11 = extractvalue { i8*, i32 } %10, 1
+ invoke fastcc void @_ZN12_GLOBAL__N_114AsmMatcherInfoD2Ev()
+ to label %32 unwind label %35
+
+; <label>:12 ; preds = %4
+ invoke void @_ZNK4llvm13CodeGenTarget10getRegBankEv()
+ to label %13 unwind label %16
+
+; <label>:13 ; preds = %12
+ br label %14
+
+; <label>:14 ; preds = %20, %13
+ %15 = icmp eq i32 undef, 0
+ br i1 %15, label %20, label %18
+
+; <label>:16 ; preds = %12
+ %17 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
+ cleanup
+ br label %26
+
+; <label>:18 ; preds = %14
+ invoke void @_ZNSs4_Rep9_S_createEjjRKSaIcE()
+ to label %19 unwind label %21
+
+; <label>:19 ; preds = %18
+ unreachable
+
+; <label>:20 ; preds = %14
+ br label %14
+
+; <label>:21 ; preds = %18
+ %22 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
+ cleanup
+ %23 = extractvalue { i8*, i32 } %22, 1
+ br i1 undef, label %26, label %24
+
+; <label>:24 ; preds = %21
+ br i1 undef, label %25, label %26
+
+; <label>:25 ; preds = %24
+ unreachable
+
+; <label>:26 ; preds = %24, %21, %16
+ %27 = phi i32 [ 0, %16 ], [ %23, %21 ], [ %23, %24 ]
+ invoke void @_ZNSt6vectorISt4pairISsSsESaIS1_EED1Ev()
+ to label %28 unwind label %30
+
+; <label>:28 ; preds = %26
+ %29 = insertvalue { i8*, i32 } undef, i32 %27, 1
+ br label %9
+
+; <label>:30 ; preds = %26
+ %31 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
+ catch i8* null
+ unreachable
+
+; <label>:32 ; preds = %9
+ br label %33
+
+; <label>:33 ; preds = %32, %5
+ %34 = phi i32 [ undef, %5 ], [ %11, %32 ]
+ unreachable
+
+; <label>:35 ; preds = %9
+ %36 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
+ catch i8* null
+ unreachable
+}
+
+declare void @_ZNK4llvm13CodeGenTarget12getAsmParserEv()
+
+declare i32 @__gxx_personality_v0(...)
+
+declare void @_ZNK4llvm6Record16getValueAsStringENS_9StringRefE()
+
+declare void @_ZN4llvm18isCurrentDebugTypeEPKc()
+
+declare fastcc void @_ZN12_GLOBAL__N_114AsmMatcherInfoD2Ev() unnamed_addr inlinehint align 2
+
+declare hidden void @_ZNSt6vectorISt4pairISsSsESaIS1_EED1Ev() unnamed_addr align 2
+
+declare void @_ZNSs4_Rep9_S_createEjjRKSaIcE()
+
+declare void @_ZNK4llvm13CodeGenTarget10getRegBankEv()
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