RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-26 04:32:44 +01:00
Code Issues Projects Releases Wiki Activity

[DebugInfo] Fix bug in LiveDebugVariables.

Browse Source 
In lib/CodeGen/LiveDebugVariables.cpp, it uses std::prev(MBBI) to
get DebugValue's SlotIndex. However, the previous instruction may be
also a debug instruction. It could not use a debug instruction to query
SlotIndex in mi2iMap.

Scan all debug instructions and use the first debug instruction to query
SlotIndex for following debug instructions. Only handle DBG_VALUE in
handleDebugValue().

Differential Revision: https://reviews.llvm.org/D50621

llvm-svn: 340508
This commit is contained in:
Hsiangkai Wang 2018-08-23 03:28:24 +00:00
parent de05e9c1b3
commit a6319a1529
3 changed files with 71 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/llvm/CodeGen/SlotIndexes.h
View File

@ -414,6 +414,8 @@ class raw_ostream;
SlotIndex getInstructionIndex(const MachineInstr &MI) const {
// Instructions inside a bundle have the same number as the bundle itself.
const MachineInstr &BundleStart = *getBundleStart(MI.getIterator());
assert(!BundleStart.isDebugInstr() &&
"Could not use a debug instruction to query mi2iMap.");
Mi2IndexMap::const_iterator itr = mi2iMap.find(&BundleStart);
assert(itr != mi2iMap.end() && "Instruction not found in maps.");
return itr->second;

15
lib/CodeGen/LiveDebugVariables.cpp
View File

@ -578,23 +578,28 @@ bool LDVImpl::collectDebugValues(MachineFunction &mf) {
MachineBasicBlock *MBB = &*MFI;
for (MachineBasicBlock::iterator MBBI = MBB->begin(), MBBE = MBB->end();
MBBI != MBBE;) {
if (!MBBI->isDebugValue()) {
// Use the first debug instruction in the sequence to get a SlotIndex
// for following consecutive debug instructions.
if (!MBBI->isDebugInstr()) {
++MBBI;
continue;
}
// DBG_VALUE has no slot index, use the previous instruction instead.
// Debug instructions has no slot index. Use the previous
// non-debug instruction's SlotIndex as its SlotIndex.
SlotIndex Idx =
MBBI == MBB->begin()
? LIS->getMBBStartIdx(MBB)
: LIS->getInstructionIndex(*std::prev(MBBI)).getRegSlot();
// Handle consecutive DBG_VALUE instructions with the same slot index.
// Handle consecutive debug instructions with the same slot index.
do {
if (handleDebugValue(*MBBI, Idx)) {
// Only handle DBG_VALUE in handleDebugValue(). Skip all other
// kinds of debug instructions.
if (MBBI->isDebugValue() && handleDebugValue(*MBBI, Idx)) {
MBBI = MBB->erase(MBBI);
Changed = true;
} else
++MBBI;
} while (MBBI != MBBE && MBBI->isDebugValue());
} while (MBBI != MBBE && MBBI->isDebugInstr());
}
}
return Changed;

59
test/DebugInfo/Generic/debug-var-slot.ll Normal file
View File

@ -0,0 +1,59 @@
; After adding new debug instruction for labels, it is possible to have
; debug instructions before DBG_VALUE. When querying DBG_VALUE's slot
; index using previous instruction and the previous instruction is debug
; instruction, it will trigger an assertion as using debug instruction
; to get slot index. This test is to emulate the case when DBG_VALUE's
; previous instruction is DBG_LABEL in LiveDebugVariables pass.
;
; RUN: llc < %s -stop-after=livedebugvars -debug 2>&1 | FileCheck %s
;
; CHECK: COMPUTING LIVE DEBUG VARIABLES: foo
; CHECK: DEBUG VARIABLES
; CHECK-NEXT: "local_var,7"
source_filename = "debug-var-slot.c"
define dso_local i32 @foo(i32 %a, i32 %b) !dbg !6 {
entry:
%a.addr = alloca i32, align 4
%b.addr = alloca i32, align 4
%sum = alloca i32, align 4
store i32 %a, i32* %a.addr, align 4
store i32 %b, i32* %b.addr, align 4
br label %top
top:
call void @llvm.dbg.label(metadata !10), !dbg !13
call void @llvm.dbg.value(metadata i32 %0, metadata !12, metadata !DIExpression()), !dbg !14
%0 = load i32, i32* %a.addr, align 4
%1 = load i32, i32* %a.addr, align 4
%2 = load i32, i32* %b.addr, align 4
%add = add nsw i32 %1, %2
store i32 %add, i32* %sum, align 4
br label %done
done:
%3 = load i32, i32* %sum, align 4
ret i32 %3, !dbg !15
}
declare void @llvm.dbg.label(metadata)
declare void @llvm.dbg.value(metadata, metadata, metadata)
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!4}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, isOptimized: true, emissionKind: FullDebug, enums: !2)
!1 = !DIFile(filename: "debug-var-slot.c", directory: "./")
!2 = !{}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!6 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 1, type: !7, isLocal: false, isDefinition: true, scopeLine: 2, isOptimized: true, unit: !0, retainedNodes: !2)
!7 = !DISubroutineType(types: !8)
!8 = !{!9, !9, !9}
!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
!10 = !DILabel(scope: !6, name: "top", file: !1, line: 4)
!11 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
!12 = !DILocalVariable(name: "local_var", scope: !6, file: !1, line: 7, type: !11)
!13 = !DILocation(line: 4, column: 1, scope: !6)
!14 = !DILocation(line: 7, column: 1, scope: !6)
!15 = !DILocation(line: 8, column: 3, scope: !6)