[llvm] f2ba939 - Reapply: [DebugInfo] Recover debug intrinsics when killing duplicated/empty...
via llvm-commits
llvm-commits at lists.llvm.org
Tue Dec 10 05:43:36 PST 2019
Author: stozer
Date: 2019-12-10T13:33:32Z
New Revision: f2ba93971ccc236c0eef5323704d31f48107e04f
URL: https://github.com/llvm/llvm-project/commit/f2ba93971ccc236c0eef5323704d31f48107e04f
DIFF: https://github.com/llvm/llvm-project/commit/f2ba93971ccc236c0eef5323704d31f48107e04f.diff
LOG: Reapply: [DebugInfo] Recover debug intrinsics when killing duplicated/empty...
basic blocks
Originally applied in 72ce759928e6dfee6a9efa310b966c19722352ba.
Fixed a build failure caused by incorrect use of cast instead of
dyn_cast.
This reverts commit 8b0780f795eb58fca0a2456e308adaaa1a0b5013.
Added:
llvm/test/Transforms/SimplifyCFG/hoist-dbgvalue-else.ll
llvm/test/Transforms/SimplifyCFG/hoist-dbgvalue-empty.ll
Modified:
llvm/include/llvm/Transforms/Utils/Local.h
llvm/lib/Transforms/Utils/Local.cpp
llvm/lib/Transforms/Utils/SimplifyCFG.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/Transforms/Utils/Local.h b/llvm/include/llvm/Transforms/Utils/Local.h
index d1dc0b3e46b9..0b50ebddd00f 100644
--- a/llvm/include/llvm/Transforms/Utils/Local.h
+++ b/llvm/include/llvm/Transforms/Utils/Local.h
@@ -178,6 +178,8 @@ bool SimplifyInstructionsInBlock(BasicBlock *BB,
/// Returns true if the dbg values have been changed.
bool replaceDbgUsesWithUndef(Instruction *I);
+void setDbgVariableUndef(DbgVariableIntrinsic *DVI);
+
//===----------------------------------------------------------------------===//
// Control Flow Graph Restructuring.
//
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 41f1dd951a84..c9d60ad2f4ad 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -485,15 +485,19 @@ void llvm::RecursivelyDeleteTriviallyDeadInstructions(
I.eraseFromParent();
}
}
+void llvm::setDbgVariableUndef(DbgVariableIntrinsic *DVI) {
+ Value *DbgValue = DVI->getVariableLocation(false);
+ Value *Undef = UndefValue::get(DbgValue ? DbgValue->getType()
+ : Type::getInt1Ty(DVI->getContext()));
+ DVI->setOperand(
+ 0, MetadataAsValue::get(DVI->getContext(), ValueAsMetadata::get(Undef)));
+}
bool llvm::replaceDbgUsesWithUndef(Instruction *I) {
SmallVector<DbgVariableIntrinsic *, 1> DbgUsers;
findDbgUsers(DbgUsers, I);
- for (auto *DII : DbgUsers) {
- Value *Undef = UndefValue::get(I->getType());
- DII->setOperand(0, MetadataAsValue::get(DII->getContext(),
- ValueAsMetadata::get(Undef)));
- }
+ for (auto *DII : DbgUsers)
+ setDbgVariableUndef(DII);
return !DbgUsers.empty();
}
@@ -1040,6 +1044,19 @@ bool llvm::TryToSimplifyUncondBranchFromEmptyBlock(BasicBlock *BB,
assert(PN->use_empty() && "There shouldn't be any uses here!");
PN->eraseFromParent();
}
+ // If Succ has multiple predecessors, each debug intrinsic in BB may or may
+ // not be valid when we reach Succ, so the debug variable should be set
+ // undef since its value is unknown.
+ Instruction *DbgInsertPoint = Succ->getFirstNonPHI();
+ while (DbgInfoIntrinsic *DI = dyn_cast<DbgInfoIntrinsic>(&BB->front())) {
+ if (auto DVI = dyn_cast<DbgVariableIntrinsic>(DI)) {
+ if (!isa<DbgDeclareInst>(DVI))
+ setDbgVariableUndef(DVI);
+ DVI->moveBefore(DbgInsertPoint);
+ } else {
+ break;
+ }
+ }
}
// If the unconditional branch we replaced contains llvm.loop metadata, we
diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index d93ca4f04cdb..681c344f87ab 100644
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -13,6 +13,7 @@
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SetOperations.h"
@@ -38,6 +39,7 @@
#include "llvm/IR/ConstantRange.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalValue.h"
@@ -1250,14 +1252,38 @@ static bool HoistThenElseCodeToIf(BranchInst *BI,
Instruction *I1 = &*BB1_Itr++, *I2 = &*BB2_Itr++;
// Skip debug info if it is not identical.
- DbgInfoIntrinsic *DBI1 = dyn_cast<DbgInfoIntrinsic>(I1);
- DbgInfoIntrinsic *DBI2 = dyn_cast<DbgInfoIntrinsic>(I2);
- if (!DBI1 || !DBI2 || !DBI1->isIdenticalToWhenDefined(DBI2)) {
- while (isa<DbgInfoIntrinsic>(I1))
- I1 = &*BB1_Itr++;
- while (isa<DbgInfoIntrinsic>(I2))
- I2 = &*BB2_Itr++;
- }
+
+ // If the terminator instruction is hoisted, and any variable locations have
+ // non-identical debug intrinsics, then those variable locations must be set
+ // as undef.
+ // FIXME: If each block contains identical debug variable intrinsics in a
+ //
diff erent order, they will be considered non-identical and be dropped.
+ MapVector<DebugVariable, DbgVariableIntrinsic *> UndefDVIs;
+
+ auto SkipDbgInfo = [&UndefDVIs](Instruction *&I,
+ BasicBlock::iterator &BB_Itr) {
+ while (isa<DbgInfoIntrinsic>(I)) {
+ if (DbgVariableIntrinsic *DVI = dyn_cast<DbgVariableIntrinsic>(I))
+ UndefDVIs.insert(
+ {DebugVariable(DVI->getVariable(), DVI->getExpression(),
+ DVI->getDebugLoc()->getInlinedAt()),
+ DVI});
+ I = &*BB_Itr++;
+ }
+ };
+
+ auto SkipNonIdenticalDbgInfo =
+ [&BB1_Itr, &BB2_Itr, &SkipDbgInfo](Instruction *&I1, Instruction *&I2) {
+ DbgInfoIntrinsic *DBI1 = dyn_cast<DbgInfoIntrinsic>(I1);
+ DbgInfoIntrinsic *DBI2 = dyn_cast<DbgInfoIntrinsic>(I2);
+ if (!DBI1 || !DBI2 || !DBI1->isIdenticalToWhenDefined(DBI2)) {
+ SkipDbgInfo(I1, BB1_Itr);
+ SkipDbgInfo(I2, BB2_Itr);
+ }
+ };
+
+ SkipNonIdenticalDbgInfo(I1, I2);
+
// FIXME: Can we define a safety predicate for CallBr?
if (isa<PHINode>(I1) || !I1->isIdenticalToWhenDefined(I2) ||
(isa<InvokeInst>(I1) && !isSafeToHoistInvoke(BB1, BB2, I1, I2)) ||
@@ -1330,15 +1356,7 @@ static bool HoistThenElseCodeToIf(BranchInst *BI,
I1 = &*BB1_Itr++;
I2 = &*BB2_Itr++;
- // Skip debug info if it is not identical.
- DbgInfoIntrinsic *DBI1 = dyn_cast<DbgInfoIntrinsic>(I1);
- DbgInfoIntrinsic *DBI2 = dyn_cast<DbgInfoIntrinsic>(I2);
- if (!DBI1 || !DBI2 || !DBI1->isIdenticalToWhenDefined(DBI2)) {
- while (isa<DbgInfoIntrinsic>(I1))
- I1 = &*BB1_Itr++;
- while (isa<DbgInfoIntrinsic>(I2))
- I2 = &*BB2_Itr++;
- }
+ SkipNonIdenticalDbgInfo(I1, I2);
} while (I1->isIdenticalToWhenDefined(I2));
return true;
@@ -1374,6 +1392,13 @@ static bool HoistThenElseCodeToIf(BranchInst *BI,
}
// Okay, it is safe to hoist the terminator.
+ for (auto DIVariableInst : UndefDVIs) {
+ DbgVariableIntrinsic *DVI = DIVariableInst.second;
+ DVI->moveBefore(BI);
+ if (DVI->getVariableLocation())
+ setDbgVariableUndef(DVI);
+ }
+
Instruction *NT = I1->clone();
BIParent->getInstList().insert(BI->getIterator(), NT);
if (!NT->getType()->isVoidTy()) {
diff --git a/llvm/test/Transforms/SimplifyCFG/hoist-dbgvalue-else.ll b/llvm/test/Transforms/SimplifyCFG/hoist-dbgvalue-else.ll
new file mode 100644
index 000000000000..32962886be5d
--- /dev/null
+++ b/llvm/test/Transforms/SimplifyCFG/hoist-dbgvalue-else.ll
@@ -0,0 +1,67 @@
+; RUN: opt -simplifycfg -S < %s | FileCheck %s
+; Checks that when the if.then and if.else blocks are both eliminated by
+; SimplifyCFG, as the common code is hoisted out, the variables with a
+; dbg.value in either of those blocks are set undef just before the
+; conditional branch instruction.
+
+define i32 @"?fn@@YAHH at Z"(i32 %foo) !dbg !8 {
+; CHECK-LABEL: entry:
+entry:
+ call void @llvm.dbg.value(metadata i32 %foo, metadata !13, metadata !DIExpression()), !dbg !16
+ call void @llvm.dbg.value(metadata i32 0, metadata !14, metadata !DIExpression()), !dbg !16
+ call void @llvm.dbg.value(metadata i32 0, metadata !15, metadata !DIExpression()), !dbg !16
+ %cmp = icmp eq i32 %foo, 4, !dbg !17
+; CHECK: call void @llvm.dbg.value(metadata i32 undef, metadata [[BEARDS:![0-9]+]]
+; CHECK: call void @llvm.dbg.value(metadata i32 undef, metadata [[BIRDS:![0-9]+]]
+ br i1 %cmp, label %if.then, label %if.else, !dbg !17
+
+if.then: ; preds = %entry
+ call void @llvm.dbg.value(metadata i32 8, metadata !14, metadata !DIExpression()), !dbg !16
+ br label %if.end, !dbg !18
+
+if.else: ; preds = %entry
+ call void @llvm.dbg.value(metadata i32 4, metadata !14, metadata !DIExpression()), !dbg !16
+ call void @llvm.dbg.value(metadata i32 8, metadata !15, metadata !DIExpression()), !dbg !16
+ br label %if.end, !dbg !21
+
+if.end: ; preds = %if.else, %if.then
+ %beards.0 = phi i32 [ 8, %if.then ], [ 4, %if.else ], !dbg !23
+ call void @llvm.dbg.value(metadata i32 %beards.0, metadata !14, metadata !DIExpression()), !dbg !16
+ ret i32 %beards.0, !dbg !24
+}
+
+declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5, !6}
+!llvm.ident = !{!7}
+
+; CHECK-LABEL: }
+; CHECK: [[BEARDS]] = !DILocalVariable(name: "beards"
+; CHECK: [[BIRDS]] = !DILocalVariable(name: "birds"
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 10.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.cpp", directory: "C:\5Cdev\5Cllvm-project", checksumkind: CSK_MD5, checksum: "64604a72fdf5b6db8aa2328236bedd6b")
+!2 = !{}
+!3 = !{i32 2, !"CodeView", i32 1}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 2}
+!6 = !{i32 7, !"PIC Level", i32 2}
+!7 = !{!"clang version 10.0.0 "}
+!8 = distinct !DISubprogram(name: "fn", linkageName: "?fn@@YAHH at Z", scope: !1, file: !1, line: 1, type: !9, scopeLine: 1, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !12)
+!9 = !DISubroutineType(types: !10)
+!10 = !{!11, !11}
+!11 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!12 = !{!13, !14, !15}
+!13 = !DILocalVariable(name: "foo", arg: 1, scope: !8, file: !1, line: 1, type: !11)
+!14 = !DILocalVariable(name: "beards", scope: !8, file: !1, line: 2, type: !11)
+!15 = !DILocalVariable(name: "birds", scope: !8, file: !1, line: 3, type: !11)
+!16 = !DILocation(line: 0, scope: !8)
+!17 = !DILocation(line: 5, scope: !8)
+!18 = !DILocation(line: 8, scope: !19)
+!19 = distinct !DILexicalBlock(scope: !20, file: !1, line: 5)
+!20 = distinct !DILexicalBlock(scope: !8, file: !1, line: 5)
+!21 = !DILocation(line: 11, scope: !22)
+!22 = distinct !DILexicalBlock(scope: !20, file: !1, line: 8)
+!23 = !DILocation(line: 0, scope: !20)
+!24 = !DILocation(line: 13, scope: !8)
diff --git a/llvm/test/Transforms/SimplifyCFG/hoist-dbgvalue-empty.ll b/llvm/test/Transforms/SimplifyCFG/hoist-dbgvalue-empty.ll
new file mode 100644
index 000000000000..7d5e32a2d656
--- /dev/null
+++ b/llvm/test/Transforms/SimplifyCFG/hoist-dbgvalue-empty.ll
@@ -0,0 +1,71 @@
+; RUN: opt -simplifycfg -S < %s | FileCheck %s
+; Checks that when the if.then block is eliminated due to containing no
+; instructions, the debug intrinsics are hoisted out of the block before its
+; deletion. The hoisted intrinsics should have undef values as the branch
+; behaviour is unknown to the intrinsics after hoisting.
+
+define dso_local i32 @"?fn@@YAHH at Z"(i32 %foo) local_unnamed_addr !dbg !8 {
+entry:
+ call void @llvm.dbg.value(metadata i32 %foo, metadata !13, metadata !DIExpression()), !dbg !16
+ call void @llvm.dbg.value(metadata i32 0, metadata !14, metadata !DIExpression()), !dbg !16
+ call void @llvm.dbg.value(metadata i32 0, metadata !15, metadata !DIExpression()), !dbg !16
+ %cmp = icmp eq i32 %foo, 4, !dbg !17
+ br i1 %cmp, label %if.then, label %if.else, !dbg !17
+
+if.then: ; preds = %entry
+ call void @llvm.dbg.value(metadata i32 8, metadata !14, metadata !DIExpression()), !dbg !16
+ call void @llvm.dbg.value(metadata i32 3, metadata !15, metadata !DIExpression()), !dbg !16
+ br label %if.end, !dbg !18
+
+if.else: ; preds = %entry
+ call void @"?side@@YAXXZ"(), !dbg !21
+ call void @llvm.dbg.value(metadata i32 4, metadata !14, metadata !DIExpression()), !dbg !16
+ call void @llvm.dbg.value(metadata i32 6, metadata !15, metadata !DIExpression()), !dbg !16
+ br label %if.end, !dbg !23
+
+; CHECK-LABEL: if.end:
+if.end: ; preds = %if.else, %if.then
+; CHECK: call void @llvm.dbg.value(metadata i32 undef, metadata [[BEARDS:![0-9]+]]
+; CHECK: call void @llvm.dbg.value(metadata i32 undef, metadata [[BIRDS:![0-9]+]]
+ %beards.0 = phi i32 [ 8, %if.then ], [ 4, %if.else ], !dbg !24
+ call void @llvm.dbg.value(metadata i32 %beards.0, metadata !14, metadata !DIExpression()), !dbg !16
+ ret i32 %beards.0, !dbg !25
+}
+
+declare dso_local void @"?side@@YAXXZ"() local_unnamed_addr
+
+declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5, !6}
+!llvm.ident = !{!7}
+
+; CHECK: [[BEARDS]] = !DILocalVariable(name: "beards"
+; CHECK: [[BIRDS]] = !DILocalVariable(name: "birds"
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 10.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test2.cpp", directory: "C:\5Cdev\5Cllvm-project", checksumkind: CSK_MD5, checksum: "8ac5d40fcc9914d6479c1a770dfdc176")
+!2 = !{}
+!3 = !{i32 2, !"CodeView", i32 1}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 2}
+!6 = !{i32 7, !"PIC Level", i32 2}
+!7 = !{!"clang version 10.0.0 "}
+!8 = distinct !DISubprogram(name: "fn", linkageName: "?fn@@YAHH at Z", scope: !1, file: !1, line: 3, type: !9, scopeLine: 3, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !12)
+!9 = !DISubroutineType(types: !10)
+!10 = !{!11, !11}
+!11 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!12 = !{!13, !14, !15}
+!13 = !DILocalVariable(name: "foo", arg: 1, scope: !8, file: !1, line: 3, type: !11)
+!14 = !DILocalVariable(name: "beards", scope: !8, file: !1, line: 4, type: !11)
+!15 = !DILocalVariable(name: "birds", scope: !8, file: !1, line: 5, type: !11)
+!16 = !DILocation(line: 0, scope: !8)
+!17 = !DILocation(line: 7, scope: !8)
+!18 = !DILocation(line: 10, scope: !19)
+!19 = distinct !DILexicalBlock(scope: !20, file: !1, line: 7)
+!20 = distinct !DILexicalBlock(scope: !8, file: !1, line: 7)
+!21 = !DILocation(line: 11, scope: !22)
+!22 = distinct !DILexicalBlock(scope: !20, file: !1, line: 10)
+!23 = !DILocation(line: 14, scope: !22)
+!24 = !DILocation(line: 0, scope: !20)
+!25 = !DILocation(line: 16, scope: !8)
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