[llvm] [DWARF] Emit line 0 source locations for BB padding nops (PR #99496)
Nabeel Omer via llvm-commits
llvm-commits at lists.llvm.org
Mon Jul 22 02:46:55 PDT 2024
https://github.com/omern1 updated https://github.com/llvm/llvm-project/pull/99496
>From 54d1dc24528f9f3e9b0b636ed0005f6b181c670d Mon Sep 17 00:00:00 2001
From: Nabeel Omer <Nabeel.Omer at sony.com>
Date: Thu, 18 Jul 2024 14:43:26 +0100
Subject: [PATCH 1/4] [DWARF] Emit line 0 source locations for BB padding nops
This patch makes LLVM emit line 0 source locations for nops emitted as
basic block padding.
Co-authored-by: Orlando Cazalet-Hyams <orlando.hyams at sony.com>
---
llvm/include/llvm/CodeGen/DebugHandlerBase.h | 2 +
llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp | 4 ++
llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 16 ++++++
llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h | 3 ++
llvm/test/CodeGen/X86/fsafdo_test1.ll | 4 +-
llvm/test/CodeGen/X86/fsafdo_test4.ll | 13 +++--
llvm/test/DebugInfo/X86/loop-align-debug.ll | 55 ++++++++++++++++++++
7 files changed, 91 insertions(+), 6 deletions(-)
create mode 100644 llvm/test/DebugInfo/X86/loop-align-debug.ll
diff --git a/llvm/include/llvm/CodeGen/DebugHandlerBase.h b/llvm/include/llvm/CodeGen/DebugHandlerBase.h
index 36a844e7087fa..30e56269b529d 100644
--- a/llvm/include/llvm/CodeGen/DebugHandlerBase.h
+++ b/llvm/include/llvm/CodeGen/DebugHandlerBase.h
@@ -137,6 +137,8 @@ class DebugHandlerBase {
void beginBasicBlockSection(const MachineBasicBlock &MBB);
void endBasicBlockSection(const MachineBasicBlock &MBB);
+ virtual void beginCodeAlignment(const MachineBasicBlock& MBB) {}
+
/// Return Label preceding the instruction.
MCSymbol *getLabelBeforeInsn(const MachineInstr *MI);
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 1f59ec545b4f7..78cb5df4bd02c 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -3967,7 +3967,11 @@ void AsmPrinter::emitBasicBlockStart(const MachineBasicBlock &MBB) {
// Emit an alignment directive for this block, if needed.
const Align Alignment = MBB.getAlignment();
if (Alignment != Align(1))
+ {
+ for (auto &Handler : DebugHandlers)
+ Handler->beginCodeAlignment(MBB);
emitAlignment(Alignment, nullptr, MBB.getMaxBytesForAlignment());
+ }
// If the block has its address taken, emit any labels that were used to
// reference the block. It is possible that there is more than one label
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 80cd5ec501f25..36e53702930f8 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -3668,3 +3668,19 @@ bool DwarfDebug::alwaysUseRanges(const DwarfCompileUnit &CU) const {
return true;
return false;
}
+
+void DwarfDebug::beginCodeAlignment(const MachineBasicBlock& MBB) {
+ auto *SP = MBB.getParent()->getFunction().getSubprogram();
+
+ bool NoDebug =
+ !SP || SP->getUnit()->getEmissionKind() == DICompileUnit::NoDebug;
+
+ if (NoDebug)
+ return;
+
+ auto PrevLoc = Asm->OutStreamer->getContext().getCurrentDwarfLoc();
+ Asm->OutStreamer->emitDwarfLocDirective(PrevLoc.getFileNum(), 0,
+ 0, 0, 0, 0, StringRef());
+ MCDwarfLineEntry::make(Asm->OutStreamer.get(),
+ Asm->OutStreamer->getCurrentSectionOnly());
+}
\ No newline at end of file
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 452485b632c45..eb474c0366d82 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -727,6 +727,9 @@ class DwarfDebug : public DebugHandlerBase {
/// Process beginning of an instruction.
void beginInstruction(const MachineInstr *MI) override;
+ /// Process beginning of code alignment.
+ void beginCodeAlignment(const MachineBasicBlock& MBB) override;
+
/// Perform an MD5 checksum of \p Identifier and return the lower 64 bits.
static uint64_t makeTypeSignature(StringRef Identifier);
diff --git a/llvm/test/CodeGen/X86/fsafdo_test1.ll b/llvm/test/CodeGen/X86/fsafdo_test1.ll
index 61c0f59aba6f8..e80a7f2f354f2 100644
--- a/llvm/test/CodeGen/X86/fsafdo_test1.ll
+++ b/llvm/test/CodeGen/X86/fsafdo_test1.ll
@@ -4,9 +4,9 @@
; Check that fs-afdo discriminators are generated.
; V01: .loc 1 7 3 is_stmt 0 discriminator 2 # foo.c:7:3
; V01: .loc 1 9 5 is_stmt 1 discriminator 2 # foo.c:9:5
-; V0: .loc 1 9 5 is_stmt 0 discriminator 11266 # foo.c:9:5
+; V0: .loc 1 9 5 discriminator 11266 # foo.c:9:5
; V0: .loc 1 7 3 is_stmt 1 discriminator 11266 # foo.c:7:3
-; V1: .loc 1 9 5 is_stmt 0 discriminator 514 # foo.c:9:5
+; V1: .loc 1 9 5 discriminator 514 # foo.c:9:5
; V1: .loc 1 7 3 is_stmt 1 discriminator 258 # foo.c:7:3
; Check that variable __llvm_fs_discriminator__ is generated.
; V01: .type __llvm_fs_discriminator__, at object # @__llvm_fs_discriminator__
diff --git a/llvm/test/CodeGen/X86/fsafdo_test4.ll b/llvm/test/CodeGen/X86/fsafdo_test4.ll
index 6a22ea9822412..aa05a0c4cd3ef 100644
--- a/llvm/test/CodeGen/X86/fsafdo_test4.ll
+++ b/llvm/test/CodeGen/X86/fsafdo_test4.ll
@@ -1,11 +1,16 @@
-; RUN: llc -enable-fs-discriminator -improved-fs-discriminator=false < %s | FileCheck %s
-; RUN: llc -enable-fs-discriminator -improved-fs-discriminator=true < %s | FileCheck %s
+; RUN: llc -enable-fs-discriminator -improved-fs-discriminator=false < %s | FileCheck --implicit-check-not=.loc %s
+; RUN: llc -enable-fs-discriminator -improved-fs-discriminator=true < %s | FileCheck --implicit-check-not=.loc %s
;
; Check that fs-afdo discriminators are NOT generated, as debugInfoForProfiling is false (not set).
+; CHECK: .loc 1 7 15 prologue_end discriminator 2 # foo.c:7:15
; CHECK: .loc 1 7 3 is_stmt 0 discriminator 2 # foo.c:7:3
+; CHECK: .loc 1 0 3 # foo.c:0:3
; CHECK: .loc 1 9 5 is_stmt 1 discriminator 2 # foo.c:9:5
-; CHECK-NOT: .loc 1 9 5 is_stmt 0 discriminator
-; CHECK-NOT: .loc 1 7 3 is_stmt 1 discriminator
+; CHECK: .loc 1 0 0 is_stmt 0 # :0:0
+; CHECK: .loc 1 9 5 discriminator 2 # foo.c:9:5
+; CHECK: .loc 1 0 0 # :0:0
+; CHECK: .loc 1 7 3 is_stmt 1 discriminator 2 # foo.c:7:3
+; CHECK: .loc 1 14 3 # foo.c:14:3
; Check that variable __llvm_fs_discriminator__ is NOT generated.
; CHECK-NOT: __llvm_fs_discriminator__:
diff --git a/llvm/test/DebugInfo/X86/loop-align-debug.ll b/llvm/test/DebugInfo/X86/loop-align-debug.ll
new file mode 100644
index 0000000000000..a0302d08faa0c
--- /dev/null
+++ b/llvm/test/DebugInfo/X86/loop-align-debug.ll
@@ -0,0 +1,55 @@
+; RUN: llc %s --filetype=obj -o %t
+; RUN: llvm-objdump -d %t | FileCheck %s --check-prefixes=OBJ
+; RUN: llvm-dwarfdump --debug-line %t | FileCheck %s --check-prefixes=DBG
+; RUN: llc %s -o - | FileCheck %s --check-prefixes=ASM
+
+; OBJ: 1:{{.*}}nop
+
+;; Address Line Column File ISA Discriminator OpIndex Flags
+; DBG: 0x0000000000000000 3 0 0 0 0 0 is_stmt
+; DBG: 0x0000000000000001 0 0 0 0 0 0
+; DBG: 0x0000000000000010 5 0 0 0 0 0 is_stmt prologue_end
+; DBG: 0x0000000000000017 5 0 0 0 0 0 is_stmt end_sequence
+
+; ASM: .loc 0 0 0 is_stmt 0
+; ASM-NEXT: .L{{.*}}:
+; ASM-NEXT: .p2align 4, 0x90
+
+;; $ cat test.cpp
+;; void g();
+;; void f() {
+;; [[clang::code_align(16)]]
+;; while (1) { g(); }
+;; }
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define dso_local void @f() local_unnamed_addr !dbg !9 {
+entry:
+ br label %while.body, !dbg !12
+
+while.body: ; preds = %entry, %while.body
+ tail call void @g(), !dbg !12
+ br label %while.body, !dbg !12, !llvm.loop !13
+}
+
+declare !dbg !16 void @g() local_unnamed_addr
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2, !3}
+!llvm.ident = !{!8}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 19.0.0git", isOptimized: true, runtimeVersion: 0, emissionKind: LineTablesOnly, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "test.cpp", directory: "/")
+!2 = !{i32 7, !"Dwarf Version", i32 5}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!8 = !{!"clang version 19.0.0git"}
+!9 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 3, type: !10, scopeLine: 3, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0)
+!10 = !DISubroutineType(types: !11)
+!11 = !{}
+!12 = !DILocation(line: 5, scope: !9)
+!13 = distinct !{!13, !12, !12, !14, !15}
+!14 = !{!"llvm.loop.mustprogress"}
+!15 = !{!"llvm.loop.align", i32 16}
+!16 = !DISubprogram(name: "g", scope: !1, file: !1, line: 2, type: !10, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized)
>From ccad1f2be751dd6272289f1b7aeae3d2e3770838 Mon Sep 17 00:00:00 2001
From: Nabeel Omer <Nabeel.Omer at sony.com>
Date: Thu, 18 Jul 2024 15:31:32 +0100
Subject: [PATCH 2/4] Fix formatting
---
llvm/include/llvm/CodeGen/DebugHandlerBase.h | 2 +-
llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp | 3 +--
llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 6 +++---
llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h | 2 +-
4 files changed, 6 insertions(+), 7 deletions(-)
diff --git a/llvm/include/llvm/CodeGen/DebugHandlerBase.h b/llvm/include/llvm/CodeGen/DebugHandlerBase.h
index 30e56269b529d..85046c200ff9b 100644
--- a/llvm/include/llvm/CodeGen/DebugHandlerBase.h
+++ b/llvm/include/llvm/CodeGen/DebugHandlerBase.h
@@ -137,7 +137,7 @@ class DebugHandlerBase {
void beginBasicBlockSection(const MachineBasicBlock &MBB);
void endBasicBlockSection(const MachineBasicBlock &MBB);
- virtual void beginCodeAlignment(const MachineBasicBlock& MBB) {}
+ virtual void beginCodeAlignment(const MachineBasicBlock &MBB) {}
/// Return Label preceding the instruction.
MCSymbol *getLabelBeforeInsn(const MachineInstr *MI);
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 78cb5df4bd02c..038dbbb9ecc2c 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -3966,8 +3966,7 @@ void AsmPrinter::emitBasicBlockStart(const MachineBasicBlock &MBB) {
// Emit an alignment directive for this block, if needed.
const Align Alignment = MBB.getAlignment();
- if (Alignment != Align(1))
- {
+ if (Alignment != Align(1)) {
for (auto &Handler : DebugHandlers)
Handler->beginCodeAlignment(MBB);
emitAlignment(Alignment, nullptr, MBB.getMaxBytesForAlignment());
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 36e53702930f8..63cfd43035ce4 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -3669,7 +3669,7 @@ bool DwarfDebug::alwaysUseRanges(const DwarfCompileUnit &CU) const {
return false;
}
-void DwarfDebug::beginCodeAlignment(const MachineBasicBlock& MBB) {
+void DwarfDebug::beginCodeAlignment(const MachineBasicBlock &MBB) {
auto *SP = MBB.getParent()->getFunction().getSubprogram();
bool NoDebug =
@@ -3679,8 +3679,8 @@ void DwarfDebug::beginCodeAlignment(const MachineBasicBlock& MBB) {
return;
auto PrevLoc = Asm->OutStreamer->getContext().getCurrentDwarfLoc();
- Asm->OutStreamer->emitDwarfLocDirective(PrevLoc.getFileNum(), 0,
- 0, 0, 0, 0, StringRef());
+ Asm->OutStreamer->emitDwarfLocDirective(PrevLoc.getFileNum(), 0, 0, 0, 0, 0,
+ StringRef());
MCDwarfLineEntry::make(Asm->OutStreamer.get(),
Asm->OutStreamer->getCurrentSectionOnly());
}
\ No newline at end of file
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index eb474c0366d82..4847e9c8bd899 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -728,7 +728,7 @@ class DwarfDebug : public DebugHandlerBase {
void beginInstruction(const MachineInstr *MI) override;
/// Process beginning of code alignment.
- void beginCodeAlignment(const MachineBasicBlock& MBB) override;
+ void beginCodeAlignment(const MachineBasicBlock &MBB) override;
/// Perform an MD5 checksum of \p Identifier and return the lower 64 bits.
static uint64_t makeTypeSignature(StringRef Identifier);
>From 09d2326b6d8d9b91a710f3ed8744a11fc61edd65 Mon Sep 17 00:00:00 2001
From: Nabeel Omer <Nabeel.Omer at sony.com>
Date: Fri, 19 Jul 2024 12:02:09 +0100
Subject: [PATCH 3/4] Don't unset column numbers
---
llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 6 +++---
llvm/test/CodeGen/X86/fsafdo_test4.ll | 4 ++--
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 63cfd43035ce4..f952f81f048a8 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -3679,8 +3679,8 @@ void DwarfDebug::beginCodeAlignment(const MachineBasicBlock &MBB) {
return;
auto PrevLoc = Asm->OutStreamer->getContext().getCurrentDwarfLoc();
- Asm->OutStreamer->emitDwarfLocDirective(PrevLoc.getFileNum(), 0, 0, 0, 0, 0,
- StringRef());
+ Asm->OutStreamer->emitDwarfLocDirective(
+ PrevLoc.getFileNum(), 0, PrevLoc.getColumn(), 0, 0, 0, StringRef());
MCDwarfLineEntry::make(Asm->OutStreamer.get(),
Asm->OutStreamer->getCurrentSectionOnly());
-}
\ No newline at end of file
+}
diff --git a/llvm/test/CodeGen/X86/fsafdo_test4.ll b/llvm/test/CodeGen/X86/fsafdo_test4.ll
index aa05a0c4cd3ef..effc72b44ade8 100644
--- a/llvm/test/CodeGen/X86/fsafdo_test4.ll
+++ b/llvm/test/CodeGen/X86/fsafdo_test4.ll
@@ -6,9 +6,9 @@
; CHECK: .loc 1 7 3 is_stmt 0 discriminator 2 # foo.c:7:3
; CHECK: .loc 1 0 3 # foo.c:0:3
; CHECK: .loc 1 9 5 is_stmt 1 discriminator 2 # foo.c:9:5
-; CHECK: .loc 1 0 0 is_stmt 0 # :0:0
+; CHECK: .loc 1 0 5 is_stmt 0 # :0:5
; CHECK: .loc 1 9 5 discriminator 2 # foo.c:9:5
-; CHECK: .loc 1 0 0 # :0:0
+; CHECK: .loc 1 0 5 # :0:5
; CHECK: .loc 1 7 3 is_stmt 1 discriminator 2 # foo.c:7:3
; CHECK: .loc 1 14 3 # foo.c:14:3
; Check that variable __llvm_fs_discriminator__ is NOT generated.
>From 5f2b03b6fda2cd468120b1f8d5b621b686f61d4e Mon Sep 17 00:00:00 2001
From: Nabeel Omer <Nabeel.Omer at sony.com>
Date: Mon, 22 Jul 2024 10:46:40 +0100
Subject: [PATCH 4/4] Move alignment check inside
---
llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp | 5 +++--
llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp | 4 +++-
2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 038dbbb9ecc2c..cd2b373f1cedf 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -3964,11 +3964,12 @@ void AsmPrinter::emitBasicBlockStart(const MachineBasicBlock &MBB) {
CurrentSectionBeginSym = MBB.getSymbol();
}
+ for (auto &Handler : DebugHandlers)
+ Handler->beginCodeAlignment(MBB);
+
// Emit an alignment directive for this block, if needed.
const Align Alignment = MBB.getAlignment();
if (Alignment != Align(1)) {
- for (auto &Handler : DebugHandlers)
- Handler->beginCodeAlignment(MBB);
emitAlignment(Alignment, nullptr, MBB.getMaxBytesForAlignment());
}
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index f952f81f048a8..a4ae39fbbe78f 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -3670,8 +3670,10 @@ bool DwarfDebug::alwaysUseRanges(const DwarfCompileUnit &CU) const {
}
void DwarfDebug::beginCodeAlignment(const MachineBasicBlock &MBB) {
- auto *SP = MBB.getParent()->getFunction().getSubprogram();
+ if (MBB.getAlignment() == Align(1))
+ return;
+ auto *SP = MBB.getParent()->getFunction().getSubprogram();
bool NoDebug =
!SP || SP->getUnit()->getEmissionKind() == DICompileUnit::NoDebug;
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