[llvm] d20a1b8 - [WebAssembly] Handle DebugLoc in DebugValueManager
Heejin Ahn via llvm-commits
llvm-commits at lists.llvm.org
Wed Apr 12 23:47:34 PDT 2023
Author: Heejin Ahn
Date: 2023-04-12T23:47:24-07:00
New Revision: d20a1b87f689a716e16477b8562fd820a72a6a8b
URL: https://github.com/llvm/llvm-project/commit/d20a1b87f689a716e16477b8562fd820a72a6a8b
DIFF: https://github.com/llvm/llvm-project/commit/d20a1b87f689a716e16477b8562fd820a72a6a8b.diff
LOG: [WebAssembly] Handle DebugLoc in DebugValueManager
According to
https://llvm.org/docs/HowToUpdateDebugInfo.html#when-to-preserve-an-instruction-location,
when moving (and in our case cloning) within the same BB, the debug
location is preserved. But when moving / cloning to a different BB, we
preserve the debug location only if the destination BB contains the same
location. Currently we preserve the debug loc unconditionally in all
cases. This CL correctly handles the debug locs in DebugValueManager.
Reviewed By: dschuff
Differential Revision: https://reviews.llvm.org/D148115
Added:
llvm/test/DebugInfo/WebAssembly/dbg-loc-reg-stackify.mir
Modified:
llvm/lib/Target/WebAssembly/WebAssemblyDebugValueManager.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyDebugValueManager.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyDebugValueManager.cpp
index 90051d03b7fff..9e97e44c4f542 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyDebugValueManager.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyDebugValueManager.cpp
@@ -226,6 +226,15 @@ bool WebAssemblyDebugValueManager::isInsertSamePlace(
return true;
}
+// Returns true if any instruction in MBB has the same debug location as DL.
+// Also returns true if DL is an empty location.
+static bool hasSameDebugLoc(const MachineBasicBlock *MBB, DebugLoc DL) {
+ for (const auto &MI : *MBB)
+ if (MI.getDebugLoc() == DL)
+ return true;
+ return false;
+}
+
// Sink 'Def', and also sink its eligible DBG_VALUEs to the place before
// 'Insert'. Convert the original DBG_VALUEs into undefs.
//
@@ -263,6 +272,12 @@ void WebAssemblyDebugValueManager::sink(MachineInstr *Insert) {
getSinkableDebugValues(Insert);
// Sink Def first.
+ //
+ // When moving to a
diff erent BB, we preserve the debug loc only if the
+ // destination BB contains the same location. See
+ // https://llvm.org/docs/HowToUpdateDebugInfo.html#when-to-preserve-an-instruction-location.
+ if (Def->getParent() != MBB && !hasSameDebugLoc(MBB, Def->getDebugLoc()))
+ Def->setDebugLoc(DebugLoc());
MBB->splice(Insert, Def->getParent(), Def);
if (DbgValues.empty())
@@ -344,6 +359,11 @@ void WebAssemblyDebugValueManager::cloneSink(MachineInstr *Insert,
// Clone Def first.
if (CloneDef) {
MachineInstr *Clone = MF->CloneMachineInstr(Def);
+ // When cloning to a
diff erent BB, we preserve the debug loc only if the
+ // destination BB contains the same location. See
+ // https://llvm.org/docs/HowToUpdateDebugInfo.html#when-to-preserve-an-instruction-location.
+ if (Def->getParent() != MBB && !hasSameDebugLoc(MBB, Def->getDebugLoc()))
+ Clone->setDebugLoc(DebugLoc());
if (NewReg != CurrentReg && NewReg.isValid())
Clone->getOperand(0).setReg(NewReg);
MBB->insert(Insert, Clone);
diff --git a/llvm/test/DebugInfo/WebAssembly/dbg-loc-reg-stackify.mir b/llvm/test/DebugInfo/WebAssembly/dbg-loc-reg-stackify.mir
new file mode 100644
index 0000000000000..7b4b500e808a6
--- /dev/null
+++ b/llvm/test/DebugInfo/WebAssembly/dbg-loc-reg-stackify.mir
@@ -0,0 +1,125 @@
+# RUN: llc -run-pass wasm-reg-stackify %s -o - | FileCheck %s
+
+--- |
+ target triple = "wasm32-unknown-unknown"
+
+ declare void @use(i32)
+
+ define void @sink_same_bb() {
+ unreachable
+ }
+ define void @clone_same_bb() {
+ unreachable
+ }
+ define void @clone_
diff erent_bb_0() {
+ unreachable
+ }
+ define void @clone_
diff erent_bb_1() {
+ unreachable
+ }
+
+ !llvm.dbg.cu = !{!0}
+ !llvm.module.flags = !{!2, !3, !4}
+
+ !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, emissionKind: FullDebug)
+ !1 = !DIFile(filename: "test.c", directory: "")
+ !2 = !{i32 7, !"Dwarf Version", i32 5}
+ !3 = !{i32 2, !"Debug Info Version", i32 3}
+ !4 = !{i32 1, !"wchar_size", i32 4}
+ !6 = distinct !DISubprogram(name: "sink_same_bb", scope: !1, file: !1, line: 1, type: !7, scopeLine: 1, unit: !0)
+ !7 = !DISubroutineType(types: !8)
+ !8 = !{null}
+...
+
+---
+# Sinking within the same BB preserves the debug location.
+# CHECK-LABEL: name: sink_same_bb
+name: sink_same_bb
+liveins:
+ - { reg: '$arguments' }
+tracksRegLiveness: true
+body: |
+ bb.0:
+ liveins: $arguments
+ %0:i32 = CONST_I32 1, implicit-def $arguments, debug-location !DILocation(line:10, scope:!6)
+ NOP implicit-def $arguments
+ CALL @use, %0:i32, implicit-def $arguments
+ RETURN implicit-def $arguments
+
+ ; CHECK: %0:i32 = CONST_I32 1, {{.*}}, debug-location !DILocation(line: 10
+ ; CHECK-NEXT: CALL @use
+...
+
+---
+# Cloning within the same BB preserves the debug location.
+# CHECK-LABEL: name: clone_same_bb
+name: clone_same_bb
+liveins:
+ - { reg: '$arguments' }
+tracksRegLiveness: true
+body: |
+ bb.0:
+ liveins: $arguments
+ %0:i32 = CONST_I32 1, implicit-def $arguments, debug-location !DILocation(line:10, scope:!6)
+ NOP implicit-def $arguments
+ CALL @use, %0:i32, implicit-def $arguments
+ CALL @use, %0:i32, implicit-def $arguments
+ RETURN implicit-def $arguments
+
+ ; CHECK: CALL @use
+ ; CHECK-NEXT: %1:i32 = CONST_I32 1, {{.*}}, debug-location !DILocation(line: 10
+ ; CHECK-NEXT: CALL @use
+...
+
+---
+# Cloning to a
diff erent BB preserves the debug location in this case because
+# the destination BB has an instruction that has the same debug location
+# (test.c:10).
+# CHECK-LABEL: name: clone_
diff erent_bb_0
+name: clone_
diff erent_bb_0
+liveins:
+ - { reg: '$arguments' }
+tracksRegLiveness: true
+body: |
+ bb.0:
+ successors: %bb.1
+ liveins: $arguments
+ %0:i32 = CONST_I32 1, implicit-def $arguments, debug-location !DILocation(line:10, scope:!6)
+ BR %bb.1, implicit-def $arguments
+
+ bb.1:
+ ; predecessors: %bb.0
+ CALL @use, %0:i32, implicit-def $arguments, debug-location !DILocation(line:10, scope:!6)
+ RETURN implicit-def $arguments
+
+ ; CHECK: bb.1:
+ ; CHECK: %1:i32 = CONST_I32 1, {{.*}}, debug-location !DILocation(line: 10
+ ; CHECK-NEXT: CALL @use, %1, {{.*}}, debug-location !DILocation(line: 10
+...
+
+---
+# Cloning to a
diff erent BB does NOT preserve the debug location in this case
+# because the destination BB doesn't have an instruction that has the same debug
+# location (It has test.c:20 but not test.c:10).
+# CHECK-LABEL: name: clone_
diff erent_bb_1
+name: clone_
diff erent_bb_1
+liveins:
+ - { reg: '$arguments' }
+tracksRegLiveness: true
+body: |
+ bb.0:
+ successors: %bb.1
+ liveins: $arguments
+ %0:i32 = CONST_I32 1, implicit-def $arguments, debug-location !DILocation(line:10, scope:!6)
+ BR %bb.1, implicit-def $arguments
+
+ bb.1:
+ ; predecessors: %bb.0
+ CALL @use, %0:i32, implicit-def $arguments, debug-location !DILocation(line:20, scope:!6)
+ RETURN implicit-def $arguments
+
+ ; CHECK: bb.1:
+ ; CHECK: %1:i32 = CONST_I32 1
+ ; CHECK-NOT: %1:i32 = CONST_I32 1, {{.*}}, debug-location !DILocation(line: 10
+ ; CHECK-NEXT: CALL @use, %1, {{.*}}, debug-location !DILocation(line: 20
+...
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