mirror of
https://github.com/capstone-engine/llvm-capstone.git
synced 2024-11-24 22:30:13 +00:00
StackColoring: better handling of statically unreachable code
Summary: Avoid assert/crash during liveness calculation in situations where the incoming machine function has statically unreachable BBs. Fixes PR37130. Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D46265 llvm-svn: 332707
This commit is contained in:
Than McIntosh
parent
b51ccaf4d4
commit
4c21a363af
@ -782,8 +782,11 @@ void StackColoring::calculateLocalLiveness() {
|
||||
for (MachineBasicBlock::const_pred_iterator PI = BB->pred_begin(),
|
||||
PE = BB->pred_end(); PI != PE; ++PI) {
|
||||
LivenessMap::const_iterator I = BlockLiveness.find(*PI);
|
||||
assert(I != BlockLiveness.end() && "Predecessor not found");
|
||||
LocalLiveIn |= I->second.LiveOut;
|
||||
// PR37130: transformations prior to stack coloring can
|
||||
// sometimes leave behind statically unreachable blocks; these
|
||||
// can be safely skipped here.
|
||||
if (I != BlockLiveness.end())
|
||||
LocalLiveIn |= I->second.LiveOut;
|
||||
}
|
||||
|
||||
// Compute LiveOut by subtracting out lifetimes that end in this
|
||||
|
||||
159
llvm/test/CodeGen/X86/PR37310.mir
Normal file
159
llvm/test/CodeGen/X86/PR37310.mir
Normal file
@ -0,0 +1,159 @@
|
||||
# RUN: llc -mtriple=x86_64-unknown-linux-gnu -mcpu=corei7 -start-before isel -no-stack-coloring=false -stop-after stack-coloring -o - %s
|
||||
|
||||
# Test to insure that the liveness analysis in the StackColoring
|
||||
# pass gracefully handles statically unreachable blocks. See PR 37310.
|
||||
|
||||
# This MIR testcase was created by compiling the following test, first
|
||||
# with "clang -emit-llvm -S" and then "llc -stop-before stack-coloring",
|
||||
# and finally editing the resulting MIR by hand to introduce a statically
|
||||
# unreachable BB (to wit: rename all bb.3 to bb.4, rename bb.2 to bb.3,
|
||||
# then add bb.2 with unconditional jump to bb.4).
|
||||
|
||||
# Original C code:
|
||||
# extern int inita(int *);
|
||||
# void foo(int x) {
|
||||
# if (x != 3) {
|
||||
# int q[128];
|
||||
# inita(&q[0]);
|
||||
# return;
|
||||
# }
|
||||
# int r[128];
|
||||
# inita(&r[x]);
|
||||
# }
|
||||
|
||||
--- |
|
||||
|
||||
define void @foo(i32 %x) {
|
||||
entry:
|
||||
%q = alloca [128 x i32], align 16
|
||||
%r = alloca [128 x i32], align 16
|
||||
%cmp = icmp eq i32 %x, 3
|
||||
br i1 %cmp, label %if.end, label %if.then
|
||||
|
||||
if.then: ; preds = %entry
|
||||
%0 = bitcast [128 x i32]* %q to i8*
|
||||
call void @llvm.lifetime.start.p0i8(i64 512, i8* nonnull %0)
|
||||
%arrayidx2 = bitcast [128 x i32]* %q to i32*
|
||||
%call = call i32 @inita(i32* nonnull %arrayidx2)
|
||||
call void @llvm.lifetime.end.p0i8(i64 512, i8* nonnull %0)
|
||||
br label %return
|
||||
|
||||
unreachable:
|
||||
br label %return
|
||||
|
||||
if.end: ; preds = %entry
|
||||
%1 = bitcast [128 x i32]* %r to i8*
|
||||
call void @llvm.lifetime.start.p0i8(i64 512, i8* nonnull %1)
|
||||
%arrayidx1 = getelementptr inbounds [128 x i32], [128 x i32]* %r, i64 0, i64 3
|
||||
%call2 = call i32 @inita(i32* nonnull %arrayidx1)
|
||||
call void @llvm.lifetime.end.p0i8(i64 512, i8* nonnull %1)
|
||||
br label %return
|
||||
|
||||
return: ; preds = %if.end, %if.then
|
||||
ret void
|
||||
}
|
||||
|
||||
declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture)
|
||||
|
||||
declare i32 @inita(i32*)
|
||||
|
||||
declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture)
|
||||
|
||||
declare void @llvm.stackprotector(i8*, i8**)
|
||||
|
||||
!llvm.module.flags = !{!0}
|
||||
!llvm.ident = !{!1}
|
||||
|
||||
!0 = !{i32 1, !"wchar_size", i32 4}
|
||||
!1 = !{!"clang version 7.0.0 (trunk 331069) (llvm/trunk 331070)"}
|
||||
|
||||
...
|
||||
---
|
||||
name: foo
|
||||
alignment: 4
|
||||
exposesReturnsTwice: false
|
||||
legalized: false
|
||||
regBankSelected: false
|
||||
selected: false
|
||||
failedISel: false
|
||||
tracksRegLiveness: true
|
||||
registers:
|
||||
- { id: 0, class: gr32, preferred-register: '' }
|
||||
- { id: 1, class: gr32, preferred-register: '' }
|
||||
- { id: 2, class: gr64, preferred-register: '' }
|
||||
- { id: 3, class: gr32, preferred-register: '' }
|
||||
- { id: 4, class: gr64, preferred-register: '' }
|
||||
- { id: 5, class: gr32, preferred-register: '' }
|
||||
liveins:
|
||||
- { reg: '$edi', virtual-reg: '%0' }
|
||||
frameInfo:
|
||||
isFrameAddressTaken: false
|
||||
isReturnAddressTaken: false
|
||||
hasStackMap: false
|
||||
hasPatchPoint: false
|
||||
stackSize: 0
|
||||
offsetAdjustment: 0
|
||||
maxAlignment: 16
|
||||
adjustsStack: false
|
||||
hasCalls: true
|
||||
stackProtector: ''
|
||||
maxCallFrameSize: 4294967295
|
||||
hasOpaqueSPAdjustment: false
|
||||
hasVAStart: false
|
||||
hasMustTailInVarArgFunc: false
|
||||
localFrameSize: 0
|
||||
savePoint: ''
|
||||
restorePoint: ''
|
||||
fixedStack:
|
||||
stack:
|
||||
- { id: 0, name: q, type: default, offset: 0, size: 512, alignment: 16,
|
||||
stack-id: 0, callee-saved-register: '', callee-saved-restored: true,
|
||||
debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
|
||||
- { id: 1, name: r, type: default, offset: 0, size: 512, alignment: 16,
|
||||
stack-id: 0, callee-saved-register: '', callee-saved-restored: true,
|
||||
debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
|
||||
constants:
|
||||
body: |
|
||||
bb.0.entry:
|
||||
successors: %bb.3(0x40000000), %bb.1(0x40000000)
|
||||
liveins: $edi
|
||||
|
||||
%0:gr32 = COPY $edi
|
||||
%1:gr32 = SUB32ri8 %0, 3, implicit-def $eflags
|
||||
JE_1 %bb.3, implicit $eflags
|
||||
JMP_1 %bb.1
|
||||
|
||||
bb.1.if.then:
|
||||
successors: %bb.4(0x80000000)
|
||||
|
||||
LIFETIME_START %stack.0.q
|
||||
ADJCALLSTACKDOWN64 0, 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp
|
||||
%2:gr64 = LEA64r %stack.0.q, 1, $noreg, 0, $noreg
|
||||
$rdi = COPY %2
|
||||
CALL64pcrel32 @inita, csr_64, implicit $rsp, implicit $ssp, implicit $rdi, implicit-def $rsp, implicit-def $ssp, implicit-def $eax
|
||||
ADJCALLSTACKUP64 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp
|
||||
%3:gr32 = COPY $eax
|
||||
LIFETIME_END %stack.0.q
|
||||
JMP_1 %bb.4
|
||||
|
||||
bb.2.unreachable:
|
||||
successors: %bb.4(0x80000000)
|
||||
|
||||
JMP_1 %bb.4
|
||||
|
||||
bb.3.if.end:
|
||||
successors: %bb.4(0x80000000)
|
||||
|
||||
LIFETIME_START %stack.1.r
|
||||
%4:gr64 = LEA64r %stack.1.r, 1, $noreg, 12, $noreg
|
||||
ADJCALLSTACKDOWN64 0, 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp
|
||||
$rdi = COPY %4
|
||||
CALL64pcrel32 @inita, csr_64, implicit $rsp, implicit $ssp, implicit $rdi, implicit-def $rsp, implicit-def $ssp, implicit-def $eax
|
||||
ADJCALLSTACKUP64 0, 0, implicit-def dead $rsp, implicit-def dead $eflags, implicit-def dead $ssp, implicit $rsp, implicit $ssp
|
||||
%5:gr32 = COPY $eax
|
||||
LIFETIME_END %stack.1.r
|
||||
|
||||
bb.4.return:
|
||||
RET 0
|
||||
|
||||
...
|
||||
Loading…
Reference in New Issue
Block a user