From f858466018346e3b59acb9e3ac7dfd5ba4c0d0a9 Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Mon, 23 Mar 2009 18:24:37 +0000 Subject: [PATCH] Fix PR3391 and PR3864. Reg allocator infinite looping. llvm-svn: 67544 --- .../llvm/CodeGen/LiveIntervalAnalysis.h | 5 ++- llvm/lib/CodeGen/LiveIntervalAnalysis.cpp | 12 ++++-- llvm/lib/CodeGen/RegAllocLinearScan.cpp | 8 +++- llvm/test/CodeGen/X86/inline-asm-out-regs.ll | 42 +++++++++++++++++++ 4 files changed, 59 insertions(+), 8 deletions(-) create mode 100644 llvm/test/CodeGen/X86/inline-asm-out-regs.ll diff --git a/llvm/include/llvm/CodeGen/LiveIntervalAnalysis.h b/llvm/include/llvm/CodeGen/LiveIntervalAnalysis.h index aec72858c832..33837a2ca231 100644 --- a/llvm/include/llvm/CodeGen/LiveIntervalAnalysis.h +++ b/llvm/include/llvm/CodeGen/LiveIntervalAnalysis.h @@ -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 diff --git a/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp b/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp index b5c21952fa3d..cd6f81c6eb23 100644 --- a/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp +++ b/llvm/lib/CodeGen/LiveIntervalAnalysis.cpp @@ -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 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, diff --git a/llvm/lib/CodeGen/RegAllocLinearScan.cpp b/llvm/lib/CodeGen/RegAllocLinearScan.cpp index e8296a74775c..912135a57f6c 100644 --- a/llvm/lib/CodeGen/RegAllocLinearScan.cpp +++ b/llvm/lib/CodeGen/RegAllocLinearScan.cpp @@ -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; } } diff --git a/llvm/test/CodeGen/X86/inline-asm-out-regs.ll b/llvm/test/CodeGen/X86/inline-asm-out-regs.ll new file mode 100644 index 000000000000..3a84bad94d0d --- /dev/null +++ b/llvm/test/CodeGen/X86/inline-asm-out-regs.ll @@ -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 ; [#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 ; [#uses=1] + %1 = icmp ugt i32 %0, 1048575 ; [#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 + ; [#uses=1] + %2 = lshr i32 %asmresult2.i.i, 8 ; [#uses=1] + %3 = trunc i32 %2 to i8 ; [#uses=1] + %4 = load i32* @pcibios_last_bus, align 4 ; [#uses=1] + %5 = icmp slt i32 %4, 0 ; [#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 + ; [#uses=1] + %6 = and i32 %asmresult4.i.i, 255 ; [#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 ; [#uses=1] + %or.cond.i.i = and i1 %7, false ; [#uses=1] + br i1 %or.cond.i.i, label %bb1.i, label %bb8.i.i + +bb8.i.i: ; preds = %bb6.i.i + unreachable +}