[llvm] [DebugInfo][SimpleLoopUnswitch] Fix missing debug location updates for new terminators (PR #98789)
Shan Huang via llvm-commits
llvm-commits at lists.llvm.org
Sat Jul 13 19:46:55 PDT 2024
https://github.com/Apochens created https://github.com/llvm/llvm-project/pull/98789
Fix #98787 .
>From b66b49c88882b93834eb6858f7db378459bf3544 Mon Sep 17 00:00:00 2001
From: Apochens <52285902006 at stu.ecnu.edu.cn>
Date: Sun, 14 Jul 2024 02:44:46 +0000
Subject: [PATCH] Fix missing debug location updates
---
.../Transforms/Scalar/SimpleLoopUnswitch.cpp | 16 ++-
...preserving-debugloc-trivial-terminators.ll | 98 +++++++++++++++++++
2 files changed, 109 insertions(+), 5 deletions(-)
create mode 100644 llvm/test/Transforms/SimpleLoopUnswitch/preserving-debugloc-trivial-terminators.ll
diff --git a/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp b/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
index fdb3211b4a438..a7e63fd8f7d8a 100644
--- a/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
+++ b/llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp
@@ -632,7 +632,8 @@ static bool unswitchTrivialBranch(Loop &L, BranchInst &BI, DominatorTree &DT,
} else {
// Create a new unconditional branch that will continue the loop as a new
// terminator.
- BranchInst::Create(ContinueBB, ParentBB);
+ Instruction *NewBI = BranchInst::Create(ContinueBB, ParentBB);
+ NewBI->setDebugLoc(BI.getDebugLoc());
}
BI.setSuccessor(LoopExitSuccIdx, UnswitchedBB);
BI.setSuccessor(1 - LoopExitSuccIdx, NewPH);
@@ -667,9 +668,11 @@ static bool unswitchTrivialBranch(Loop &L, BranchInst &BI, DominatorTree &DT,
if (FullUnswitch) {
if (MSSAU) {
// Remove the cloned branch instruction.
- ParentBB->getTerminator()->eraseFromParent();
+ Instruction *Term = ParentBB->getTerminator();
+ Term->eraseFromParent();
// Create unconditional branch now.
- BranchInst::Create(ContinueBB, ParentBB);
+ Instruction *NewBI = BranchInst::Create(ContinueBB, ParentBB);
+ NewBI->setDebugLoc(Term->getDebugLoc());
MSSAU->removeEdge(ParentBB, LoopExitBB);
}
DT.deleteEdge(ParentBB, LoopExitBB);
@@ -859,10 +862,12 @@ static bool unswitchTrivialSwitch(Loop &L, SwitchInst &SI, DominatorTree &DT,
// the switch.
BasicBlock *OldPH = L.getLoopPreheader();
BasicBlock *NewPH = SplitEdge(OldPH, L.getHeader(), &DT, &LI, MSSAU);
- OldPH->getTerminator()->eraseFromParent();
+ Instruction *Term = OldPH->getTerminator();
// Now add the unswitched switch.
auto *NewSI = SwitchInst::Create(LoopCond, NewPH, ExitCases.size(), OldPH);
+ NewSI->setDebugLoc(Term->getDebugLoc());
+ Term->eraseFromParent();
SwitchInstProfUpdateWrapper NewSIW(*NewSI);
// Rewrite the IR for the unswitched basic blocks. This requires two steps.
@@ -973,7 +978,8 @@ static bool unswitchTrivialSwitch(Loop &L, SwitchInst &SI, DominatorTree &DT,
}
// Now nuke the switch and replace it with a direct branch.
SIW.eraseFromParent();
- BranchInst::Create(CommonSuccBB, BB);
+ Instruction *NewBI = BranchInst::Create(CommonSuccBB, BB);
+ NewBI->setDebugLoc(SIW->getDebugLoc());
} else if (DefaultExitBB) {
assert(SI.getNumCases() > 0 &&
"If we had no cases we'd have a common successor!");
diff --git a/llvm/test/Transforms/SimpleLoopUnswitch/preserving-debugloc-trivial-terminators.ll b/llvm/test/Transforms/SimpleLoopUnswitch/preserving-debugloc-trivial-terminators.ll
new file mode 100644
index 0000000000000..3691d0f2eaafb
--- /dev/null
+++ b/llvm/test/Transforms/SimpleLoopUnswitch/preserving-debugloc-trivial-terminators.ll
@@ -0,0 +1,98 @@
+; RUN: opt -passes='loop(simple-loop-unswitch)' -S < %s | FileCheck %s
+; RUN: opt -passes='loop-mssa(simple-loop-unswitch)' -S < %s | FileCheck %s
+
+; Check that SimpleLoopUnswitch's unswitchTrivialBranch() and unswitchTrivialSwitch()
+; propagates debug locations to the new terminators replacing the old ones.
+
+define i32 @test1(ptr %var, i1 %cond1, i1 %cond2) !dbg !5 {
+; CHECK-LABEL: define i32 @test1(
+; CHECK: loop_begin:
+; CHECK-NEXT: br label %[[CONTINUE:.*]], !dbg [[DBG8:![0-9]+]]
+;
+entry:
+ br label %loop_begin, !dbg !8
+
+loop_begin: ; preds = %do_something, %entry
+ br i1 %cond1, label %continue, label %loop_exit, !dbg !9
+
+continue: ; preds = %loop_begin
+ %var_val = load i32, ptr %var, align 4, !dbg !10
+ br i1 %cond2, label %do_something, label %loop_exit, !dbg !11
+
+do_something: ; preds = %continue
+ call void @some_func(), !dbg !12
+ br label %loop_begin, !dbg !13
+
+loop_exit: ; preds = %continue, %loop_begin
+ ret i32 0, !dbg !14
+}
+
+define i32 @test7(i32 %cond1, i32 %x, i32 %y) !dbg !15 {
+; CHECK-LABEL: define i32 @test7(
+; CHECK-SAME: i32 [[COND1:%.*]], i32 [[X:%.*]], i32 [[Y:%.*]])
+; CHECK-NEXT: entry:
+; CHECK-NEXT: switch i32 [[COND1]], label %[[ENTRY_SPLIT:.*]] [
+; CHECK-NEXT: i32 0, label %[[LOOP_EXIT:.*]]
+; CHECK-NEXT: i32 1, label %[[LOOP_EXIT]]
+; CHECK-NEXT: ], !dbg [[DBG16:![0-9]+]]
+; CHECK: loop_begin:
+; CHECK-NEXT: br label %[[LATCH:.*]], !dbg [[DBG17:![0-9]+]]
+;
+entry:
+ br label %loop_begin, !dbg !16
+
+loop_begin: ; preds = %latch, %entry
+ switch i32 %cond1, label %latch [
+ i32 0, label %loop_exit
+ i32 1, label %loop_exit
+ ], !dbg !17
+
+latch: ; preds = %loop_begin
+ call void @some_func(), !dbg !18
+ br label %loop_begin, !dbg !19
+
+loop_exit: ; preds = %loop_begin, %loop_begin
+ %result1 = phi i32 [ %x, %loop_begin ], [ %x, %loop_begin ], !dbg !20
+ %result2 = phi i32 [ %y, %loop_begin ], [ %y, %loop_begin ], !dbg !21
+ %result = add i32 %result1, %result2, !dbg !22
+ ret i32 %result, !dbg !23
+}
+
+; Function Attrs: noreturn
+declare void @some_func()
+
+!llvm.dbg.cu = !{!0}
+!llvm.debugify = !{!2, !3}
+!llvm.module.flags = !{!4}
+
+; CHECK: [[DBG8]] = !DILocation(line: 2,
+
+; CHECK: [[DBG16]] = !DILocation(line: 8,
+; CHECK: [[DBG17]] = !DILocation(line: 9,
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C, file: !1, producer: "debugify", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug)
+!1 = !DIFile(filename: "test2.ll", directory: "/")
+!2 = !{i32 15}
+!3 = !{i32 0}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = distinct !DISubprogram(name: "test1", linkageName: "test1", scope: null, file: !1, line: 1, type: !6, scopeLine: 1, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0)
+!6 = !DISubroutineType(types: !7)
+!7 = !{}
+!8 = !DILocation(line: 1, column: 1, scope: !5)
+!9 = !DILocation(line: 2, column: 1, scope: !5)
+!10 = !DILocation(line: 3, column: 1, scope: !5)
+!11 = !DILocation(line: 4, column: 1, scope: !5)
+!12 = !DILocation(line: 5, column: 1, scope: !5)
+!13 = !DILocation(line: 6, column: 1, scope: !5)
+!14 = !DILocation(line: 7, column: 1, scope: !5)
+!15 = distinct !DISubprogram(name: "test7", linkageName: "test7", scope: null, file: !1, line: 8, type: !6, scopeLine: 8, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0)
+!16 = !DILocation(line: 8, column: 1, scope: !15)
+!17 = !DILocation(line: 9, column: 1, scope: !15)
+!18 = !DILocation(line: 10, column: 1, scope: !15)
+!19 = !DILocation(line: 11, column: 1, scope: !15)
+!20 = !DILocation(line: 12, column: 1, scope: !15)
+!21 = !DILocation(line: 13, column: 1, scope: !15)
+!22 = !DILocation(line: 14, column: 1, scope: !15)
+!23 = !DILocation(line: 15, column: 1, scope: !15)
+
+
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