Fix PR3391 and PR3864. Reg allocator infinite looping.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67544 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2009-03-23 18:24:37 +00:00
parent 8cccf0ef0c
commit 2824a65550
4 changed files with 59 additions and 8 deletions

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@ -367,8 +367,9 @@ namespace llvm {
VirtRegMap &vrm, float& SSWeight);
/// spillPhysRegAroundRegDefsUses - Spill the specified physical register
/// around all defs and uses of the specified interval.
void spillPhysRegAroundRegDefsUses(const LiveInterval &li,
/// around all defs and uses of the specified interval. Return true if it
/// was able to cut its interval.
bool spillPhysRegAroundRegDefsUses(const LiveInterval &li,
unsigned PhysReg, VirtRegMap &vrm);
/// isReMaterializable - Returns true if every definition of MI of every

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@ -2214,8 +2214,9 @@ unsigned LiveIntervals::getNumConflictsWithPhysReg(const LiveInterval &li,
}
/// spillPhysRegAroundRegDefsUses - Spill the specified physical register
/// around all defs and uses of the specified interval.
void LiveIntervals::spillPhysRegAroundRegDefsUses(const LiveInterval &li,
/// around all defs and uses of the specified interval. Return true if it
/// was able to cut its interval.
bool LiveIntervals::spillPhysRegAroundRegDefsUses(const LiveInterval &li,
unsigned PhysReg, VirtRegMap &vrm) {
unsigned SpillReg = getRepresentativeReg(PhysReg);
@ -2226,6 +2227,7 @@ void LiveIntervals::spillPhysRegAroundRegDefsUses(const LiveInterval &li,
assert(*AS == SpillReg || !allocatableRegs_[*AS] ||
tri_->isSuperRegister(*AS, SpillReg));
bool Cut = false;
LiveInterval &pli = getInterval(SpillReg);
SmallPtrSet<MachineInstr*, 8> SeenMIs;
for (MachineRegisterInfo::reg_iterator I = mri_->reg_begin(li.reg),
@ -2240,9 +2242,10 @@ void LiveIntervals::spillPhysRegAroundRegDefsUses(const LiveInterval &li,
vrm.addEmergencySpill(SpillReg, MI);
unsigned StartIdx = getLoadIndex(Index);
unsigned EndIdx = getStoreIndex(Index)+1;
if (pli.isInOneLiveRange(StartIdx, EndIdx))
if (pli.isInOneLiveRange(StartIdx, EndIdx)) {
pli.removeRange(StartIdx, EndIdx);
else {
Cut = true;
} else {
cerr << "Ran out of registers during register allocation!\n";
if (MI->getOpcode() == TargetInstrInfo::INLINEASM) {
cerr << "Please check your inline asm statement for invalid "
@ -2260,6 +2263,7 @@ void LiveIntervals::spillPhysRegAroundRegDefsUses(const LiveInterval &li,
}
}
}
return Cut;
}
LiveRange LiveIntervals::addLiveRangeToEndOfBlock(unsigned reg,

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@ -869,8 +869,12 @@ void RALinScan::assignRegOrStackSlotAtInterval(LiveInterval* cur)
if (cur->weight == HUGE_VALF ||
li_->getApproximateInstructionCount(*cur) == 0) {
// Spill a physical register around defs and uses.
li_->spillPhysRegAroundRegDefsUses(*cur, minReg, *vrm_);
assignRegOrStackSlotAtInterval(cur);
if (li_->spillPhysRegAroundRegDefsUses(*cur, minReg, *vrm_))
assignRegOrStackSlotAtInterval(cur);
else {
cerr << "Ran out of registers during register allocation!\n";
exit(1);
}
return;
}
}

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@ -0,0 +1,42 @@
; RUN: llvm-as < %s | llc -mtriple=i386-unknown-linux-gnu
; XFAIL: *
; Expected to run out of registers during allocation.
; PR3391
@pci_indirect = external global { } ; <{ }*> [#uses=1]
@pcibios_last_bus = external global i32 ; <i32*> [#uses=2]
define void @pci_pcbios_init() nounwind section ".init.text" {
entry:
br label %bb1.i
bb1.i: ; preds = %bb6.i.i, %bb1.i, %entry
%0 = load i32* null, align 8 ; <i32> [#uses=1]
%1 = icmp ugt i32 %0, 1048575 ; <i1> [#uses=1]
br i1 %1, label %bb2.i, label %bb1.i
bb2.i: ; preds = %bb1.i
%asmtmp.i.i = tail call { i32, i32, i32, i32 } asm "lcall *(%edi); cld\0A\09jc 1f\0A\09xor %ah, %ah\0A1:", "={dx},={ax},={bx},={cx},1,{di},~{dirflag},~{fpsr},~{flags},~{memory}"(i32 45313, { }* @pci_indirect) nounwind ; <{ i32, i32, i32, i32 }> [#uses=2]
%asmresult2.i.i = extractvalue { i32, i32, i32, i32 } %asmtmp.i.i, 1
; <i32> [#uses=1]
%2 = lshr i32 %asmresult2.i.i, 8 ; <i32> [#uses=1]
%3 = trunc i32 %2 to i8 ; <i8> [#uses=1]
%4 = load i32* @pcibios_last_bus, align 4 ; <i32> [#uses=1]
%5 = icmp slt i32 %4, 0 ; <i1> [#uses=1]
br i1 %5, label %bb5.i.i, label %bb6.i.i
bb5.i.i: ; preds = %bb2.i
%asmresult4.i.i = extractvalue { i32, i32, i32, i32 } %asmtmp.i.i, 3
; <i32> [#uses=1]
%6 = and i32 %asmresult4.i.i, 255 ; <i32> [#uses=1]
store i32 %6, i32* @pcibios_last_bus, align 4
br label %bb6.i.i
bb6.i.i: ; preds = %bb5.i.i, %bb2.i
%7 = icmp eq i8 %3, 0 ; <i1> [#uses=1]
%or.cond.i.i = and i1 %7, false ; <i1> [#uses=1]
br i1 %or.cond.i.i, label %bb1.i, label %bb8.i.i
bb8.i.i: ; preds = %bb6.i.i
unreachable
}