--- Reverse-merging (from foreign repository) r67049 into '.':
U test/CodeGen/X86/2009-03-13-PHIElimBug.ll
D test/CodeGen/X86/2009-03-16-PHIElimInLPad.ll
U lib/CodeGen/PHIElimination.cpp
r67049 was causing this failure:
Running /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.src/test/CodeGen/X86/dg.exp ...
FAIL: /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.src/test/CodeGen/X86/2009-03-13-PHIElimBug.ll for PR3784
Failed with exit(1) at line 1
while running: llvm-as < /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvm.src/test/CodeGen/X86/2009-03-13-PHIElimBug.ll | llc -march=x86 | /usr/bin/grep -A 2 {call f} | /usr/bin/grep movl
child process exited abnormally
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67051 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/PHIElimination.cpp b/lib/CodeGen/PHIElimination.cpp
index 67c555f..6f3c82c 100644
--- a/lib/CodeGen/PHIElimination.cpp
+++ b/lib/CodeGen/PHIElimination.cpp
@@ -14,8 +14,6 @@
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "phielim"
-#include "llvm/BasicBlock.h"
-#include "llvm/Instructions.h"
#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
@@ -33,6 +31,7 @@
using namespace llvm;
STATISTIC(NumAtomic, "Number of atomic phis lowered");
+STATISTIC(NumEH, "Number of EH try blocks skipped");
namespace {
class VISIBILITY_HIDDEN PNE : public MachineFunctionPass {
@@ -67,25 +66,8 @@
///
void analyzePHINodes(const MachineFunction& Fn);
- // FindCopyInsertPoint - Find a safe place in MBB to insert a copy from
- // SrcReg. This needs to be after any def or uses of SrcReg, but before
- // any subsequent point where control flow might jump out of the basic
- // block.
- MachineBasicBlock::iterator FindCopyInsertPoint(MachineBasicBlock &MBB,
- unsigned SrcReg);
-
- // SkipPHIsAndLabels - Copies need to be inserted after phi nodes and
- // also after any exception handling labels: in landing pads execution
- // starts at the label, so any copies placed before it won't be executed!
- MachineBasicBlock::iterator SkipPHIsAndLabels(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator I) {
- // Rather than assuming that EH labels come before other kinds of labels,
- // just skip all labels.
- while (I != MBB.end() &&
- (I->getOpcode() == TargetInstrInfo::PHI || I->isLabel()))
- ++I;
- return I;
- }
+ void WalkPassEHTryRange(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator &I, unsigned SrcReg);
typedef std::pair<const MachineBasicBlock*, unsigned> BBVRegPair;
typedef std::map<BBVRegPair, unsigned> VRegPHIUse;
@@ -138,7 +120,10 @@
// Get an iterator to the first instruction after the last PHI node (this may
// also be the end of the basic block).
- MachineBasicBlock::iterator AfterPHIsIt = SkipPHIsAndLabels(MBB, MBB.begin());
+ MachineBasicBlock::iterator AfterPHIsIt = MBB.begin();
+ while (AfterPHIsIt != MBB.end() &&
+ AfterPHIsIt->getOpcode() == TargetInstrInfo::PHI)
+ ++AfterPHIsIt; // Skip over all of the PHI nodes...
while (MBB.front().getOpcode() == TargetInstrInfo::PHI)
LowerAtomicPHINode(MBB, AfterPHIsIt);
@@ -159,47 +144,37 @@
return true;
}
-// FindCopyInsertPoint - Find a safe place in MBB to insert a copy from SrcReg.
-// This needs to be after any def or uses of SrcReg, but before any subsequent
-// point where control flow might jump out of the basic block.
-MachineBasicBlock::iterator PNE::FindCopyInsertPoint(MachineBasicBlock &MBB,
- unsigned SrcReg) {
- // Handle the trivial case trivially.
- if (MBB.empty())
- return MBB.begin();
+void PNE::WalkPassEHTryRange(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator &I, unsigned SrcReg) {
+ if (I == MBB.begin())
+ return;
+ MachineBasicBlock::iterator PI = prior(I);
+ if (PI->getOpcode() != TargetInstrInfo::EH_LABEL)
+ return;
- // If this basic block does not contain an invoke, then control flow always
- // reaches the end of it, so place the copy there. The logic below works in
- // this case too, but is more expensive.
- if (!isa<InvokeInst>(MBB.getBasicBlock()->getTerminator()))
- return MBB.getFirstTerminator();
-
- // Discover any definition/uses in this basic block.
- SmallPtrSet<MachineInstr*, 8> DefUsesInMBB;
- for (MachineRegisterInfo::reg_iterator RI = MRI->reg_begin(SrcReg),
- RE = MRI->reg_end(); RI != RE; ++RI) {
- MachineInstr *DefUseMI = &*RI;
- if (DefUseMI->getParent() == &MBB)
- DefUsesInMBB.insert(DefUseMI);
+ // Trying to walk pass the EH try range. If we run into a use instruction,
+ // we want to insert the copy there.
+ SmallPtrSet<MachineInstr*, 4> UsesInMBB;
+ for (MachineRegisterInfo::use_iterator UI = MRI->use_begin(SrcReg),
+ UE = MRI->use_end(); UI != UE; ++UI) {
+ MachineInstr *UseMI = &*UI;
+ if (UseMI->getParent() == &MBB)
+ UsesInMBB.insert(UseMI);
}
- MachineBasicBlock::iterator InsertPoint;
- if (DefUsesInMBB.empty()) {
- // No def/uses. Insert the copy at the start of the basic block.
- InsertPoint = MBB.begin();
- } else if (DefUsesInMBB.size() == 1) {
- // Insert the copy immediately after the definition/use.
- InsertPoint = *DefUsesInMBB.begin();
- ++InsertPoint;
- } else {
- // Insert the copy immediately after the last definition/use.
- InsertPoint = MBB.end();
- while (!DefUsesInMBB.count(&*--InsertPoint)) {}
- ++InsertPoint;
+ while (PI != MBB.begin()) {
+ --PI;
+ if (PI->getOpcode() == TargetInstrInfo::EH_LABEL) {
+ ++NumEH;
+ I = PI;
+ return;
+ } else if (UsesInMBB.count(&*PI)) {
+ ++NumEH;
+ I = next(PI);
+ return;
+ }
}
-
- // Make sure the copy goes after any phi nodes however.
- return SkipPHIsAndLabels(MBB, InsertPoint);
+ return;
}
/// LowerAtomicPHINode - Lower the PHI node at the top of the specified block,
@@ -298,7 +273,10 @@
// Find a safe location to insert the copy, this may be the first terminator
// in the block (or end()).
- MachineBasicBlock::iterator InsertPos = FindCopyInsertPoint(opBlock, SrcReg);
+ MachineBasicBlock::iterator InsertPos = opBlock.getFirstTerminator();
+
+ // Walk pass EH try range if needed.
+ WalkPassEHTryRange(opBlock, InsertPos, SrcReg);
// Insert the copy.
TII->copyRegToReg(opBlock, InsertPos, IncomingReg, SrcReg, RC, RC);