[llvm] [RegisterCoalescer] Deferring deletion of instructions in `ErasedInstrs` until the end of an iteration (PR #79820)
Quentin Dian via llvm-commits
llvm-commits at lists.llvm.org
Mon Jan 29 04:58:17 PST 2024
https://github.com/DianQK created https://github.com/llvm/llvm-project/pull/79820
Fixes #79718.
The same instructions may exist in an iteration. We cannot immediately delete instructions in `ErasedInstrs`.
Here's my debug logs, you can see that the instructions that are about to be processed have appeared in the work list ahead of time.
```
BB: foo:preheader work list:
BB: foo:bb3 work list:
BB: foo:bb4 work list:
%52:gpr = COPY %7:gpr in foo:bb4
BB: foo:bb2 work list:
%52:gpr = COPY %7:gpr in foo:bb4
BB: foo:bb6 work list:
%52:gpr = COPY %7:gpr in foo:bb4
BB: foo:loopexit work list:
%48:gpr = COPY %44:gpr in foo:bb4
BB: foo:bb5 work list:
%45:gpr = COPY %43:gpr in foo:bb3.bb5_crit_edge // Instruction changes!
BB: foo:BB3 work list:
%45:gpr = COPY %43:gpr in foo:bb3.bb5_crit_edge
BB: foo:preheader.preheader work list:
%45:gpr = COPY %43:gpr in foo:bb3.bb5_crit_edge
BB: foo:BB6 work list:
%45:gpr = COPY %43:gpr in foo:bb3.bb5_crit_edge
%43:gpr = COPY %45:gpr in foo:BB6
BB: foo:bb3.bb5_crit_edge work list:
%45:gpr = COPY %43:gpr in foo:bb3.bb5_crit_edge // Same instruction!
%43:gpr = COPY %45:gpr in foo:BB6
%44:gpr = COPY %41:gpr in foo:bb3.bb5_crit_edge
%45:gpr = COPY %43:gpr in foo:bb3.bb5_crit_edge // Same instruction!
BB: foo:bb1 work list:
%45:gpr = COPY %43:gpr in foo:bb3.bb5_crit_edge
%43:gpr = COPY %45:gpr in foo:BB6
%44:gpr = COPY %41:gpr in foo:bb3.bb5_crit_edge
%45:gpr = COPY %43:gpr in foo:bb3.bb5_crit_edge
%0:gpr = COPY %43:gpr in foo:bb1
BB: foo:start work list:
%45:gpr = COPY %43:gpr in foo:bb3.bb5_crit_edge
%43:gpr = COPY %45:gpr in foo:BB6
%44:gpr = COPY %41:gpr in foo:bb3.bb5_crit_edge
%45:gpr = COPY %43:gpr in foo:bb3.bb5_crit_edge
%0:gpr = COPY %43:gpr in foo:bb1
llc: llvm-project/llvm/include/llvm/CodeGen/MachineOperand.h:370: Register llvm::MachineOperand::getReg() const: Assertion `isReg() && "This is not a register operand!"' failed.
```
This change is probably due to `removePartialRedundancy`.
<details><summary>Address sanitizer logs</summary>
<p>
```
=================================================================
==200228==ERROR: AddressSanitizer: use-after-poison on address 0x521000054728 at pc 0x7efc7fd597ad bp 0x7ffd3d4d1d10 sp 0x7ffd3d4d1d08
READ of size 8 at 0x521000054728 thread T0
#0 0x7efc7fd597ac in llvm::MachineInstr::getOpcode() const /home/dianqk/llvm/llvm-project/llvm/include/llvm/CodeGen/MachineInstr.h:543:39
#1 0x7efc7fd597ac in llvm::MachineInstr::isCopy() const /home/dianqk/llvm/llvm-project/llvm/include/llvm/CodeGen/MachineInstr.h:1392:12
#2 0x7efc7fd597ac in isMoveInstr(llvm::TargetRegisterInfo const&, llvm::MachineInstr const*, llvm::Register&, llvm::Register&, unsigned int&, unsigned int&) /home/dianqk/llvm/llvm-project/llvm/lib/CodeGen/RegisterCoalescer.cpp:419:13
#3 0x7efc7fd57b06 in llvm::CoalescerPair::setRegisters(llvm::MachineInstr const*) /home/dianqk/llvm/llvm-project/llvm/lib/CodeGen/RegisterCoalescer.cpp:459:8
#4 0x7efc7fd7039c in (anonymous namespace)::RegisterCoalescer::joinCopy(llvm::MachineInstr*, bool&) /home/dianqk/llvm/llvm-project/llvm/lib/CodeGen/RegisterCoalescer.cpp:1972:11
#5 0x7efc7fd6dbaa in (anonymous namespace)::RegisterCoalescer::copyCoalesceWorkList(llvm::MutableArrayRef<llvm::MachineInstr*>) /home/dianqk/llvm/llvm-project/llvm/lib/CodeGen/RegisterCoalescer.cpp:3995:20
#6 0x7efc7fd5fcde in (anonymous namespace)::RegisterCoalescer::joinAllIntervals() /home/dianqk/llvm/llvm-project/llvm/lib/CodeGen/RegisterCoalescer.cpp:4156:10
#7 0x7efc7fd5fcde in (anonymous namespace)::RegisterCoalescer::runOnMachineFunction(llvm::MachineFunction&) /home/dianqk/llvm/llvm-project/llvm/lib/CodeGen/RegisterCoalescer.cpp:4228:5
#8 0x7efc7f70f043 in llvm::MachineFunctionPass::runOnFunction(llvm::Function&) /home/dianqk/llvm/llvm-project/llvm/lib/CodeGen/MachineFunctionPass.cpp:93:13
#9 0x7efc79d0db54 in llvm::FPPassManager::runOnFunction(llvm::Function&) /home/dianqk/llvm/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:1445:27
#10 0x7efc79d260e3 in llvm::FPPassManager::runOnModule(llvm::Module&) /home/dianqk/llvm/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:1491:16
#11 0x7efc79d0ea3f in (anonymous namespace)::MPPassManager::runOnModule(llvm::Module&) /home/dianqk/llvm/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:1560:27
#12 0x7efc79d0ea3f in llvm::legacy::PassManagerImpl::run(llvm::Module&) /home/dianqk/llvm/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:542:44
#13 0x55b3617ef9f4 in compileModule(char**, llvm::LLVMContext&) /home/dianqk/llvm/llvm-project/llvm/tools/llc/llc.cpp:743:8
#14 0x55b3617e8c9f in main /home/dianqk/llvm/llvm-project/llvm/tools/llc/llc.cpp:412:22
#15 0x7efc7823f0cd in __libc_start_call_main (/nix/store/p3jshbwxiwifm1py0yq544fmdyy98j8a-glibc-2.38-27/lib/libc.so.6+0x280cd) (BuildId: 155a1ecbcb77ab0451b398b8a9c19795d8e7b047)
#16 0x7efc7823f188 in __libc_start_main at GLIBC_2.2.5 (/nix/store/p3jshbwxiwifm1py0yq544fmdyy98j8a-glibc-2.38-27/lib/libc.so.6+0x28188) (BuildId: 155a1ecbcb77ab0451b398b8a9c19795d8e7b047)
#17 0x55b3616af774 in _start (/home/dianqk/llvm/llvm-project/build/bin/llc+0x97774)
0x521000054728 is located 2600 bytes inside of 4096-byte region [0x521000053d00,0x521000054d00)
allocated by thread T0 here:
#0 0x55b3617e2050 in operator new(unsigned long, std::align_val_t) (/home/dianqk/llvm/llvm-project/build/bin/llc+0x1ca050)
#1 0x7efc78c4142d in llvm::allocate_buffer(unsigned long, unsigned long) /home/dianqk/llvm/llvm-project/llvm/lib/Support/MemAlloc.cpp:16:10
#2 0x7efc7f03e5c1 in llvm::MallocAllocator::Allocate(unsigned long, unsigned long) /home/dianqk/llvm/llvm-project/llvm/include/llvm/Support/AllocatorBase.h:92:12
#3 0x7efc7f03e5c1 in llvm::BumpPtrAllocatorImpl<llvm::MallocAllocator, 4096ul, 4096ul, 128ul>::StartNewSlab() /home/dianqk/llvm/llvm-project/llvm/include/llvm/Support/Allocator.h:339:42
#4 0x7efc7f03e5c1 in llvm::BumpPtrAllocatorImpl<llvm::MallocAllocator, 4096ul, 4096ul, 128ul>::Allocate(unsigned long, llvm::Align) /home/dianqk/llvm/llvm-project/llvm/include/llvm/Support/Allocator.h:195:5
#5 0x7efc7f6e22bb in llvm::BumpPtrAllocatorImpl<llvm::MallocAllocator, 4096ul, 4096ul, 128ul>::Allocate(unsigned long, unsigned long) /home/dianqk/llvm/llvm-project/llvm/include/llvm/Support/Allocator.h:209:12
#6 0x7efc7f6e22bb in llvm::MachineInstr* llvm::Recycler<llvm::MachineInstr, 72ul, 8ul>::Allocate<llvm::MachineInstr, llvm::BumpPtrAllocatorImpl<llvm::MallocAllocator, 4096ul, 4096ul, 128ul>>(llvm::BumpPtrAllocatorImpl<llvm::MallocAllocator, 4096ul, 4096ul, 128ul>&) /home/dianqk/llvm/llvm-project/llvm/include/llvm/Support/Recycler.h:89:57
#7 0x7efc7f6e22bb in llvm::MachineFunction::CreateMachineInstr(llvm::MCInstrDesc const&, llvm::DebugLoc, bool) /home/dianqk/llvm/llvm-project/llvm/lib/CodeGen/MachineFunction.cpp:399:35
#8 0x7efc838dcb8a in llvm::BuildMI(llvm::MachineBasicBlock&, llvm::MachineInstrBundleIterator<llvm::MachineInstr, false>, llvm::MIMetadata const&, llvm::MCInstrDesc const&, llvm::Register) /home/dianqk/llvm/llvm-project/llvm/include/llvm/CodeGen/MachineInstrBuilder.h:386:25
#9 0x7efc838fbe8e in llvm::TargetInstrInfo::createPHISourceCopy(llvm::MachineBasicBlock&, llvm::MachineInstrBundleIterator<llvm::MachineInstr, false>, llvm::DebugLoc const&, llvm::Register, unsigned int, llvm::Register) const /home/dianqk/llvm/llvm-project/llvm/include/llvm/CodeGen/TargetInstrInfo.h:2048:12
#10 0x7efc7fbc09c6 in (anonymous namespace)::PHIElimination::LowerPHINode(llvm::MachineBasicBlock&, llvm::MachineInstrBundleIterator<llvm::MachineInstr, false>) /home/dianqk/llvm/llvm-project/llvm/lib/CodeGen/PHIElimination.cpp:522:28
#11 0x7efc7fbb6dfe in (anonymous namespace)::PHIElimination::EliminatePHINodes(llvm::MachineFunction&, llvm::MachineBasicBlock&) /home/dianqk/llvm/llvm-project/llvm/lib/CodeGen/PHIElimination.cpp:243:5
#12 0x7efc7fbb6dfe in (anonymous namespace)::PHIElimination::runOnMachineFunction(llvm::MachineFunction&) /home/dianqk/llvm/llvm-project/llvm/lib/CodeGen/PHIElimination.cpp:198:16
#13 0x7efc7f70f043 in llvm::MachineFunctionPass::runOnFunction(llvm::Function&) /home/dianqk/llvm/llvm-project/llvm/lib/CodeGen/MachineFunctionPass.cpp:93:13
#14 0x7efc79d0db54 in llvm::FPPassManager::runOnFunction(llvm::Function&) /home/dianqk/llvm/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:1445:27
#15 0x7efc79d260e3 in llvm::FPPassManager::runOnModule(llvm::Module&) /home/dianqk/llvm/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:1491:16
#16 0x7efc79d0ea3f in (anonymous namespace)::MPPassManager::runOnModule(llvm::Module&) /home/dianqk/llvm/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:1560:27
#17 0x7efc79d0ea3f in llvm::legacy::PassManagerImpl::run(llvm::Module&) /home/dianqk/llvm/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:542:44
#18 0x55b3617ef9f4 in compileModule(char**, llvm::LLVMContext&) /home/dianqk/llvm/llvm-project/llvm/tools/llc/llc.cpp:743:8
#19 0x55b3617e8c9f in main /home/dianqk/llvm/llvm-project/llvm/tools/llc/llc.cpp:412:22
#20 0x7efc7823f0cd in __libc_start_call_main (/nix/store/p3jshbwxiwifm1py0yq544fmdyy98j8a-glibc-2.38-27/lib/libc.so.6+0x280cd) (BuildId: 155a1ecbcb77ab0451b398b8a9c19795d8e7b047)
SUMMARY: AddressSanitizer: use-after-poison /home/dianqk/llvm/llvm-project/llvm/include/llvm/CodeGen/MachineInstr.h:543:39 in llvm::MachineInstr::getOpcode() const
Shadow bytes around the buggy address:
0x521000054480: 00 00 00 00 00 00 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7
0x521000054500: f7 00 00 00 00 00 00 00 00 f7 f7 f7 f7 f7 f7 f7
0x521000054580: f7 f7 f7 f7 00 00 00 00 00 00 00 00 f7 f7 f7 f7
0x521000054600: f7 f7 f7 f7 f7 f7 f7 00 00 00 00 00 00 00 00 f7
0x521000054680: f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 00 00 00 00 00 00
=>0x521000054700: 00 00 f7 f7 f7[f7]f7 f7 f7 f7 f7 f7 f7 00 00 00
0x521000054780: 00 00 00 00 00 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7
0x521000054800: 00 00 00 00 00 00 00 00 f7 f7 f7 f7 f7 f7 f7 f7
0x521000054880: f7 f7 f7 00 00 00 00 00 00 00 00 f7 00 00 00 00
0x521000054900: 00 00 00 00 00 f7 00 00 00 00 00 00 00 00 f7 00
0x521000054980: 00 00 00 00 00 00 00 00 f7 00 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
==200228==ABORTING
```
</p>
</details>
>From 6528a77b15b3b9728f574e637e9c05d6d1e6b058 Mon Sep 17 00:00:00 2001
From: DianQK <dianqk at dianqk.net>
Date: Mon, 29 Jan 2024 18:58:04 +0800
Subject: [PATCH 1/2] Pre-commit test cases
---
.../register-coalescer-crash-pr79718.mir | 317 ++++++++++++++++++
1 file changed, 317 insertions(+)
create mode 100644 llvm/test/CodeGen/LoongArch/register-coalescer-crash-pr79718.mir
diff --git a/llvm/test/CodeGen/LoongArch/register-coalescer-crash-pr79718.mir b/llvm/test/CodeGen/LoongArch/register-coalescer-crash-pr79718.mir
new file mode 100644
index 000000000000000..13381318eee02ca
--- /dev/null
+++ b/llvm/test/CodeGen/LoongArch/register-coalescer-crash-pr79718.mir
@@ -0,0 +1,317 @@
+# XFAIL: *
+# RUN: llc -o - %s -mtriple=loongarch64 \
+# RUN: -run-pass=register-coalescer -join-liveintervals=1 -join-splitedges=0 2>&1 | FileCheck %s
+
+--- |
+ source_filename = "register-coalescer-crash-pr79718.ll"
+ target datalayout = "e-m:e-p:64:64-i64:64-i128:128-n64-S128"
+ target triple = "loongarch64"
+
+ define void @foo(ptr nocapture writeonly %0, i1 %1, i1 %2, i1 %3, i1 %4) local_unnamed_addr #0 {
+ start:
+ br label %bb1
+ bb1: ; preds = %bb6, %start
+ %5 = phi i64 [ 0, %start ], [ %20, %bb6 ]
+ %6 = phi i64 [ 0, %start ], [ %21, %bb6 ]
+ %7 = phi i64 [ undef, %start ], [ %23, %bb6 ]
+ br label %bb2
+
+ bb2: ; preds = %bb6, %bb1
+ %8 = phi i64 [ %5, %bb1 ], [ %20, %bb6 ]
+ %9 = phi i64 [ %6, %bb1 ], [ %21, %bb6 ]
+ %10 = phi i64 [ %6, %bb1 ], [ %22, %bb6 ]
+ %11 = phi i64 [ %7, %bb1 ], [ %23, %bb6 ]
+ br i1 %1, label %loopexit, label %preheader.preheader
+
+ preheader.preheader: ; preds = %bb2
+ br label %preheader
+
+ preheader: ; preds = %bb4, %preheader.preheader
+ %12 = phi i64 [ %14, %bb4 ], [ %10, %preheader.preheader ]
+ %13 = load volatile { i64, i64 }, ptr null, align 4294967296
+ br i1 %2, label %bb3, label %bb5
+
+ bb3: ; preds = %preheader
+ br i1 %3, label %bb4, label %bb3.bb5_crit_edge
+
+ bb4: ; preds = %bb3
+ %14 = add i64 %12, 1
+ br i1 %4, label %loopexit, label %preheader
+
+ loopexit: ; preds = %bb4, %bb2
+ %15 = phi i64 [ %9, %bb2 ], [ %14, %bb4 ]
+ %16 = phi i64 [ %10, %bb2 ], [ %14, %bb4 ]
+ store i8 0, ptr %0, align 1
+ br label %bb6
+
+ bb3.bb5_crit_edge: ; preds = %bb3
+ %17 = add i64 %12, 1
+ br label %bb5
+
+ bb5: ; preds = %preheader, %bb3.bb5_crit_edge
+ %18 = phi i64 [ 1, %bb3.bb5_crit_edge ], [ 0, %preheader ]
+ %19 = phi i64 [ %17, %bb3.bb5_crit_edge ], [ %11, %preheader ]
+ store i64 0, ptr %0, align 8
+ br label %bb6
+
+ bb6: ; preds = %bb5, %loopexit
+ %20 = phi i64 [ %19, %bb5 ], [ %8, %loopexit ]
+ %21 = phi i64 [ %18, %bb5 ], [ %15, %loopexit ]
+ %22 = phi i64 [ %18, %bb5 ], [ %16, %loopexit ]
+ %23 = phi i64 [ %19, %bb5 ], [ %11, %loopexit ]
+ %24 = icmp eq i64 %5, 1
+ br i1 %24, label %bb2, label %bb1
+ }
+
+ attributes #0 = { nofree norecurse noreturn nounwind }
+
+...
+---
+name: foo
+alignment: 32
+exposesReturnsTwice: false
+legalized: false
+regBankSelected: false
+selected: false
+failedISel: false
+tracksRegLiveness: true
+hasWinCFI: false
+callsEHReturn: false
+callsUnwindInit: false
+hasEHCatchret: false
+hasEHScopes: false
+hasEHFunclets: false
+isOutlined: false
+debugInstrRef: false
+failsVerification: false
+tracksDebugUserValues: false
+registers:
+ - { id: 0, class: gpr, preferred-register: '' }
+ - { id: 1, class: gpr, preferred-register: '' }
+ - { id: 2, class: gpr, preferred-register: '' }
+ - { id: 3, class: gpr, preferred-register: '' }
+ - { id: 4, class: gpr, preferred-register: '' }
+ - { id: 5, class: gpr, preferred-register: '' }
+ - { id: 6, class: gpr, preferred-register: '' }
+ - { id: 7, class: gpr, preferred-register: '' }
+ - { id: 8, class: gpr, preferred-register: '' }
+ - { id: 9, class: gpr, preferred-register: '' }
+ - { id: 10, class: gpr, preferred-register: '' }
+ - { id: 11, class: gpr, preferred-register: '' }
+ - { id: 12, class: gpr, preferred-register: '' }
+ - { id: 13, class: gpr, preferred-register: '' }
+ - { id: 14, class: gpr, preferred-register: '' }
+ - { id: 15, class: gpr, preferred-register: '' }
+ - { id: 16, class: gpr, preferred-register: '' }
+ - { id: 17, class: gpr, preferred-register: '' }
+ - { id: 18, class: gpr, preferred-register: '' }
+ - { id: 19, class: gpr, preferred-register: '' }
+ - { id: 20, class: gpr, preferred-register: '' }
+ - { id: 21, class: gpr, preferred-register: '' }
+ - { id: 22, class: gpr, preferred-register: '' }
+ - { id: 23, class: gpr, preferred-register: '' }
+ - { id: 24, class: gpr, preferred-register: '' }
+ - { id: 25, class: gpr, preferred-register: '' }
+ - { id: 26, class: gpr, preferred-register: '' }
+ - { id: 27, class: gpr, preferred-register: '' }
+ - { id: 28, class: gpr, preferred-register: '' }
+ - { id: 29, class: gpr, preferred-register: '' }
+ - { id: 30, class: gpr, preferred-register: '' }
+ - { id: 31, class: gpr, preferred-register: '' }
+ - { id: 32, class: gpr, preferred-register: '' }
+ - { id: 33, class: gpr, preferred-register: '' }
+ - { id: 34, class: gpr, preferred-register: '' }
+ - { id: 35, class: gpr, preferred-register: '' }
+ - { id: 36, class: gpr, preferred-register: '' }
+ - { id: 37, class: gpr, preferred-register: '' }
+ - { id: 38, class: gpr, preferred-register: '' }
+ - { id: 39, class: gpr, preferred-register: '' }
+ - { id: 40, class: gpr, preferred-register: '' }
+ - { id: 41, class: gpr, preferred-register: '' }
+ - { id: 42, class: gpr, preferred-register: '' }
+ - { id: 43, class: gpr, preferred-register: '' }
+ - { id: 44, class: gpr, preferred-register: '' }
+ - { id: 45, class: gpr, preferred-register: '' }
+ - { id: 46, class: gpr, preferred-register: '' }
+ - { id: 47, class: gpr, preferred-register: '' }
+ - { id: 48, class: gpr, preferred-register: '' }
+ - { id: 49, class: gpr, preferred-register: '' }
+ - { id: 50, class: gpr, preferred-register: '' }
+ - { id: 51, class: gpr, preferred-register: '' }
+ - { id: 52, class: gpr, preferred-register: '' }
+ - { id: 53, class: gpr, preferred-register: '' }
+ - { id: 54, class: gpr, preferred-register: '' }
+ - { id: 55, class: gpr, preferred-register: '' }
+ - { id: 56, class: gpr, preferred-register: '' }
+ - { id: 57, class: gpr, preferred-register: '' }
+ - { id: 58, class: gpr, preferred-register: '' }
+liveins:
+ - { reg: '$r4', virtual-reg: '%18' }
+ - { reg: '$r5', virtual-reg: '%19' }
+ - { reg: '$r6', virtual-reg: '%20' }
+ - { reg: '$r7', virtual-reg: '%21' }
+ - { reg: '$r8', virtual-reg: '%22' }
+frameInfo:
+ isFrameAddressTaken: false
+ isReturnAddressTaken: false
+ hasStackMap: false
+ hasPatchPoint: false
+ stackSize: 0
+ offsetAdjustment: 0
+ maxAlignment: 1
+ adjustsStack: false
+ hasCalls: false
+ stackProtector: ''
+ functionContext: ''
+ maxCallFrameSize: 4294967295
+ cvBytesOfCalleeSavedRegisters: 0
+ hasOpaqueSPAdjustment: false
+ hasVAStart: false
+ hasMustTailInVarArgFunc: false
+ hasTailCall: false
+ localFrameSize: 0
+ savePoint: ''
+ restorePoint: ''
+fixedStack: []
+stack: []
+entry_values: []
+callSites: []
+debugValueSubstitutions: []
+constants: []
+machineFunctionInfo: {}
+body: |
+ bb.0.start:
+ successors: %bb.1(0x80000000)
+ liveins: $r4, $r5, $r6, $r7, $r8
+
+ %22:gpr = COPY killed $r8
+ %21:gpr = COPY killed $r7
+ %20:gpr = COPY killed $r6
+ %19:gpr = COPY killed $r5
+ %18:gpr = COPY killed $r4
+ %29:gpr = COPY $r0
+ %27:gpr = COPY killed %29
+ %30:gpr = ANDI killed %19, 1
+ %41:gpr = ORI $r0, 1
+ %35:gpr = ANDI killed %20, 1
+ %36:gpr = ANDI killed %21, 1
+ %39:gpr = ANDI killed %22, 1
+ %43:gpr = COPY %27
+ %44:gpr = COPY killed %27
+ %45:gpr = IMPLICIT_DEF
+
+ bb.1.bb1:
+ successors: %bb.2(0x80000000)
+
+ %2:gpr = COPY killed %45
+ %1:gpr = COPY killed %44
+ %0:gpr = COPY killed %43
+ %46:gpr = COPY %0
+ %47:gpr = COPY %1
+ %48:gpr = COPY killed %1
+ %49:gpr = COPY killed %2
+
+ bb.2.bb2:
+ successors: %bb.12(0x40000000), %bb.3(0x40000000)
+
+ %6:gpr = COPY killed %49
+ %5:gpr = COPY killed %48
+ %4:gpr = COPY killed %47
+ %3:gpr = COPY killed %46
+ BEQZ %30, %bb.3
+
+ bb.12:
+ successors: %bb.8(0x80000000)
+
+ %51:gpr = COPY killed %4
+ %52:gpr = COPY killed %5
+ PseudoBR %bb.8
+
+ bb.3.preheader.preheader:
+ successors: %bb.4(0x80000000)
+
+ %50:gpr = COPY killed %5
+
+ bb.4.preheader:
+ successors: %bb.6(0x7c000000), %bb.5(0x04000000)
+
+ %7:gpr = COPY killed %50
+ dead %33:gpr = LD_D $r0, 8 :: (volatile load (s64) from `ptr null` + 8, basealign 4294967296)
+ dead %34:gpr = LD_D $r0, 0 :: (volatile load (s64) from `ptr null`, align 4294967296)
+ BNEZ %35, %bb.6
+
+ bb.5:
+ successors: %bb.10(0x80000000)
+
+ %32:gpr = COPY $r0
+ %31:gpr = COPY killed %32
+ %53:gpr = COPY killed %31
+ %54:gpr = COPY killed %6
+ PseudoBR %bb.10
+
+ bb.6.bb3:
+ successors: %bb.7(0x7c000000), %bb.9(0x04000000)
+
+ BEQZ %36, %bb.9
+ PseudoBR %bb.7
+
+ bb.7.bb4:
+ successors: %bb.8(0x04000000), %bb.4(0x7c000000)
+
+ %8:gpr = ADDI_D killed %7, 1
+ %50:gpr = COPY %8
+ %51:gpr = COPY %8
+ %52:gpr = COPY killed %8
+ BEQZ %39, %bb.4
+ PseudoBR %bb.8
+
+ bb.8.loopexit:
+ successors: %bb.11(0x80000000)
+
+ %10:gpr = COPY killed %52
+ %9:gpr = COPY killed %51
+ %40:gpr = COPY $r0
+ ST_B killed %40, %18, 0 :: (store (s8) into %ir.0)
+ %55:gpr = COPY killed %3
+ %56:gpr = COPY killed %9
+ %57:gpr = COPY killed %10
+ %58:gpr = COPY killed %6
+ PseudoBR %bb.11
+
+ bb.9.bb3.bb5_crit_edge:
+ successors: %bb.10(0x80000000)
+
+ %42:gpr = ADDI_D killed %7, 1
+ %53:gpr = COPY %41
+ %54:gpr = COPY killed %42
+
+ bb.10.bb5:
+ successors: %bb.11(0x80000000)
+
+ %13:gpr = COPY killed %54
+ %12:gpr = COPY killed %53
+ %38:gpr = COPY $r0
+ ST_D killed %38, %18, 0 :: (store (s64) into %ir.0)
+ %55:gpr = COPY %13
+ %56:gpr = COPY %12
+ %57:gpr = COPY killed %12
+ %58:gpr = COPY killed %13
+
+ bb.11.bb6:
+ successors: %bb.2(0x7c000000), %bb.1(0x04000000)
+
+ %17:gpr = COPY killed %58
+ %16:gpr = COPY killed %57
+ %15:gpr = COPY killed %56
+ %14:gpr = COPY killed %55
+ %43:gpr = COPY %14
+ %44:gpr = COPY %15
+ %45:gpr = COPY %17
+ %46:gpr = COPY killed %14
+ %47:gpr = COPY killed %15
+ %48:gpr = COPY killed %16
+ %49:gpr = COPY killed %17
+ BEQ %0, %41, %bb.2
+ PseudoBR %bb.1
+
+...
>From 9cb9ad2d4cb30013c17a2220587e56a927058757 Mon Sep 17 00:00:00 2001
From: DianQK <dianqk at dianqk.net>
Date: Mon, 29 Jan 2024 19:20:35 +0800
Subject: [PATCH 2/2] [RegisterCoalescer] Deferring deletion of instructions in
`ErasedInstrs` until the end of an iteration
---
llvm/lib/CodeGen/RegisterCoalescer.cpp | 16 ++--
.../register-coalescer-crash-pr79718.mir | 89 ++++++++++++++++++-
2 files changed, 98 insertions(+), 7 deletions(-)
diff --git a/llvm/lib/CodeGen/RegisterCoalescer.cpp b/llvm/lib/CodeGen/RegisterCoalescer.cpp
index cbb1a74049fbd7b..d3125fba67206b2 100644
--- a/llvm/lib/CodeGen/RegisterCoalescer.cpp
+++ b/llvm/lib/CodeGen/RegisterCoalescer.cpp
@@ -236,7 +236,8 @@ namespace {
/// was successfully coalesced away. If it is not currently possible to
/// coalesce this interval, but it may be possible if other things get
/// coalesced, then it returns true by reference in 'Again'.
- bool joinCopy(MachineInstr *CopyMI, bool &Again);
+ bool joinCopy(MachineInstr *CopyMI, bool &Again,
+ SmallPtrSetImpl<MachineInstr *> &CurrentErasedInstrs);
/// Attempt to join these two intervals. On failure, this
/// returns false. The output "SrcInt" will not have been modified, so we
@@ -1964,7 +1965,9 @@ void RegisterCoalescer::setUndefOnPrunedSubRegUses(LiveInterval &LI,
LIS->shrinkToUses(&LI);
}
-bool RegisterCoalescer::joinCopy(MachineInstr *CopyMI, bool &Again) {
+bool RegisterCoalescer::joinCopy(
+ MachineInstr *CopyMI, bool &Again,
+ SmallPtrSetImpl<MachineInstr *> &CurrentErasedInstrs) {
Again = false;
LLVM_DEBUG(dbgs() << LIS->getInstructionIndex(*CopyMI) << '\t' << *CopyMI);
@@ -2156,7 +2159,9 @@ bool RegisterCoalescer::joinCopy(MachineInstr *CopyMI, bool &Again) {
// 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);
+ if (ErasedInstrs.erase(CopyMI))
+ // But we may encounter the instruction again in this iteration.
+ CurrentErasedInstrs.insert(CopyMI);
// Rewrite all SrcReg operands to DstReg.
// Also update DstReg operands to include DstIdx if it is set.
@@ -3982,17 +3987,18 @@ void RegisterCoalescer::lateLiveIntervalUpdate() {
bool RegisterCoalescer::
copyCoalesceWorkList(MutableArrayRef<MachineInstr*> CurrList) {
bool Progress = false;
+ SmallPtrSet<MachineInstr *, 4> CurrentErasedInstrs;
for (MachineInstr *&MI : CurrList) {
if (!MI)
continue;
// Skip instruction pointers that have already been erased, for example by
// dead code elimination.
- if (ErasedInstrs.count(MI)) {
+ if (ErasedInstrs.count(MI) || CurrentErasedInstrs.count(MI)) {
MI = nullptr;
continue;
}
bool Again = false;
- bool Success = joinCopy(MI, Again);
+ bool Success = joinCopy(MI, Again, CurrentErasedInstrs);
Progress |= Success;
if (Success || !Again)
MI = nullptr;
diff --git a/llvm/test/CodeGen/LoongArch/register-coalescer-crash-pr79718.mir b/llvm/test/CodeGen/LoongArch/register-coalescer-crash-pr79718.mir
index 13381318eee02ca..5e0be0df636b8bf 100644
--- a/llvm/test/CodeGen/LoongArch/register-coalescer-crash-pr79718.mir
+++ b/llvm/test/CodeGen/LoongArch/register-coalescer-crash-pr79718.mir
@@ -1,6 +1,6 @@
-# XFAIL: *
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 4
# RUN: llc -o - %s -mtriple=loongarch64 \
-# RUN: -run-pass=register-coalescer -join-liveintervals=1 -join-splitedges=0 2>&1 | FileCheck %s
+# RUN: -run-pass=register-coalescer -join-liveintervals=1 -join-splitedges=0 | FileCheck %s
--- |
source_filename = "register-coalescer-crash-pr79718.ll"
@@ -180,6 +180,91 @@ debugValueSubstitutions: []
constants: []
machineFunctionInfo: {}
body: |
+ ; CHECK-LABEL: name: foo
+ ; CHECK: bb.0.start:
+ ; CHECK-NEXT: successors: %bb.1(0x80000000)
+ ; CHECK-NEXT: liveins: $r4, $r5, $r6, $r7, $r8
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: [[COPY:%[0-9]+]]:gpr = COPY $r8
+ ; CHECK-NEXT: [[COPY1:%[0-9]+]]:gpr = COPY $r7
+ ; CHECK-NEXT: [[COPY2:%[0-9]+]]:gpr = COPY $r6
+ ; CHECK-NEXT: [[COPY3:%[0-9]+]]:gpr = COPY $r5
+ ; CHECK-NEXT: [[COPY4:%[0-9]+]]:gpr = COPY $r4
+ ; CHECK-NEXT: [[ANDI:%[0-9]+]]:gpr = ANDI [[COPY3]], 1
+ ; CHECK-NEXT: [[ORI:%[0-9]+]]:gpr = ORI $r0, 1
+ ; CHECK-NEXT: [[ANDI1:%[0-9]+]]:gpr = ANDI [[COPY2]], 1
+ ; CHECK-NEXT: [[ANDI2:%[0-9]+]]:gpr = ANDI [[COPY1]], 1
+ ; CHECK-NEXT: [[ANDI3:%[0-9]+]]:gpr = ANDI [[COPY]], 1
+ ; CHECK-NEXT: [[COPY5:%[0-9]+]]:gpr = COPY $r0
+ ; CHECK-NEXT: [[COPY6:%[0-9]+]]:gpr = COPY $r0
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.1.bb1:
+ ; CHECK-NEXT: successors: %bb.2(0x80000000)
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: [[COPY7:%[0-9]+]]:gpr = COPY [[COPY5]]
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.2.bb2:
+ ; CHECK-NEXT: successors: %bb.3(0x40000000), %bb.4(0x40000000)
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: BEQZ [[ANDI]], %bb.4
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.3:
+ ; CHECK-NEXT: successors: %bb.9(0x80000000)
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: PseudoBR %bb.9
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.4.preheader.preheader:
+ ; CHECK-NEXT: successors: %bb.5(0x80000000)
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.5.preheader:
+ ; CHECK-NEXT: successors: %bb.7(0x7c000000), %bb.6(0x04000000)
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: dead [[LD_D:%[0-9]+]]:gpr = LD_D $r0, 8 :: (volatile load (s64) from `ptr null` + 8, basealign 4294967296)
+ ; CHECK-NEXT: dead [[LD_D1:%[0-9]+]]:gpr = LD_D $r0, 0 :: (volatile load (s64) from `ptr null`, align 4294967296)
+ ; CHECK-NEXT: BNEZ [[ANDI1]], %bb.7
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.6:
+ ; CHECK-NEXT: successors: %bb.11(0x80000000)
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: [[COPY6:%[0-9]+]]:gpr = COPY $r0
+ ; CHECK-NEXT: PseudoBR %bb.11
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.7.bb3:
+ ; CHECK-NEXT: successors: %bb.8(0x7c000000), %bb.10(0x04000000)
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: BEQZ [[ANDI2]], %bb.10
+ ; CHECK-NEXT: PseudoBR %bb.8
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.8.bb4:
+ ; CHECK-NEXT: successors: %bb.9(0x04000000), %bb.5(0x7c000000)
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: [[COPY6:%[0-9]+]]:gpr = ADDI_D [[COPY6]], 1
+ ; CHECK-NEXT: BEQZ [[ANDI3]], %bb.5
+ ; CHECK-NEXT: PseudoBR %bb.9
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.9.loopexit:
+ ; CHECK-NEXT: successors: %bb.12(0x80000000)
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: ST_B $r0, [[COPY4]], 0 :: (store (s8) into %ir.0)
+ ; CHECK-NEXT: PseudoBR %bb.12
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.10.bb3.bb5_crit_edge:
+ ; CHECK-NEXT: successors: %bb.11(0x80000000)
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: [[COPY5:%[0-9]+]]:gpr = ADDI_D [[COPY6]], 1
+ ; CHECK-NEXT: [[COPY6:%[0-9]+]]:gpr = COPY [[ORI]]
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.11.bb5:
+ ; CHECK-NEXT: successors: %bb.12(0x80000000)
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: ST_D $r0, [[COPY4]], 0 :: (store (s64) into %ir.0)
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: bb.12.bb6:
+ ; CHECK-NEXT: successors: %bb.2(0x7c000000), %bb.1(0x04000000)
+ ; CHECK-NEXT: {{ $}}
+ ; CHECK-NEXT: BEQ [[COPY7]], [[ORI]], %bb.2
+ ; CHECK-NEXT: PseudoBR %bb.1
bb.0.start:
successors: %bb.1(0x80000000)
liveins: $r4, $r5, $r6, $r7, $r8
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