jmorse created this revision.
jmorse added reviewers: StephenTozer, Orlando, TWeaver, djtodoro.
Herald added subscribers: dang, pengfei, hiraditya.
jmorse requested review of this revision.
Herald added projects: clang, LLVM.
Herald added subscribers: llvm-commits, cfe-commits.
This patch makes instruction referencing on-by-default for x86, as discussed in
https://lists.llvm.org/pipermail/llvm-dev/2021-November/153653.html . I'm sure
there'll be an amount of unexpected breakage, so I'll land in two parts, with a
minimal sized patch switching the default so that reverting is easy.
It seems there are a number of complicated interactions between the cc1
arguments and the codegen flags -- I don't really want to untangle them, so
I've just removed the cc1 argument for instruction referencing. It'll still be
accessible with `-mllvm -experimental-debug-variable-locations=true`
This is probably the point to discuss tests that I'm not intending on updating
for instruction referencing and still have
-experimental-debug-variable-locations=false in the arguments. They are:
MIR/X86/dvl-livedebugvalues-clobber.mir
MIR/X86/dvl-livedebugvalues-join.mir
MIR/X86/dvl-livedebugvalues-movements.mir
MIR/X86/dvl-livedebugvalues-spillrestore.mir
X86/dbg-val-list-dangling.ll
^ they involve variadic variable locations, which is currently "future work"
for December,
MIR/X86/kill-after-spill.mir
MIR/X86/live-debug-values-restore-collide.mir
MIR/X86/mlicm-hoist-post-regalloc.mir
X86/live-debug-variables.ll
X86/live-debug-vars-discard-invalid.mir
X86/live-debug-vars-intervals.mir
MIR/X86/live-debug-vars-unused-arg-debugonly.mir
MIR/X86/live-debug-vars-unused-arg.mir
MIR/X86/livedebugvars-crossbb-interval.mir
MIR/X86/backup-entry-values-usage.mir
^ these all test very DBG_VALUE specific parts of code, usuallly
LiveDebugVariables which is a no-op when using instruction referencing. One of
them tests what VarLocBasedLDV does does with spills when they're followed by
kill flags, which is another thing InstrRefBasedLDV doesn't care about.
Generic/linear-dbg-value.ll
^ this seems to just check that DBG_VALUE instructions are generated, I don't
think it's really testing any interesting behaviours.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D114631
Files:
clang/include/clang/Driver/Options.td
llvm/include/llvm/CodeGen/CommandFlags.h
llvm/lib/CodeGen/CommandFlags.cpp
llvm/lib/Target/X86/X86TargetMachine.cpp
llvm/test/DebugInfo/X86/instr-ref-flag.ll
Index: llvm/test/DebugInfo/X86/instr-ref-flag.ll
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/X86/instr-ref-flag.ll
@@ -0,0 +1,46 @@
+; RUN: llc %s -o - -stop-before=finalize-isel -march=x86-64 \
+; RUN: | FileCheck %s --check-prefixes=INSTRREFON
+; RUN: llc %s -o - -stop-before=finalize-isel -march=x86-64 \
+; RUN: -experimental-debug-variable-locations=true \
+; RUN: | FileCheck %s --check-prefixes=INSTRREFON
+
+; RUN: llc %s -o - -stop-before=finalize-isel -march=x86-64 \
+; RUN: -experimental-debug-variable-locations=false \
+; RUN: | FileCheck %s --check-prefixes=INSTRREFOFF \
+; RUN: --implicit-check-not=DBG_INSTR_REF
+
+;; This test checks that for an x86 triple, instruction referencing is used
+;; by llc by default, and that it can be turned explicitly on or off as
+;; desired.
+
+; INSTRREFON: DBG_INSTR_REF
+; INSTRREFOFF: DBG_VALUE
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-unknown"
+
+define hidden i32 @foo(i32 %a) local_unnamed_addr !dbg !7 {
+ %b = add i32 %a, 1
+ call void @llvm.dbg.value(metadata i32 %b, metadata !11, metadata !DIExpression()), !dbg !12
+ ret i32 %b, !dbg !12
+}
+
+; Function Attrs: nofree nosync nounwind readnone speculatable willreturn
+declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5, !6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug)
+!1 = !DIFile(filename: "foo.cpp", directory: ".")
+!2 = !DIBasicType(name: "int", size: 8, encoding: DW_ATE_signed)
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 2}
+!6 = !{i32 7, !"PIC Level", i32 2}
+!7 = distinct !DISubprogram(name: "foo", linkageName: "foo", scope: !1, file: !1, line: 6, type: !8, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !10)
+!8 = !DISubroutineType(types: !9)
+!9 = !{!2, !2}
+!10 = !{!11}
+!11 = !DILocalVariable(name: "baz", scope: !7, file: !1, line: 7, type: !2)
+!12 = !DILocation(line: 10, scope: !7)
Index: llvm/lib/Target/X86/X86TargetMachine.cpp
===================================================================
--- llvm/lib/Target/X86/X86TargetMachine.cpp
+++ llvm/lib/Target/X86/X86TargetMachine.cpp
@@ -26,6 +26,7 @@
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/CodeGen/CommandFlags.h"
#include "llvm/CodeGen/ExecutionDomainFix.h"
#include "llvm/CodeGen/GlobalISel/CallLowering.h"
#include "llvm/CodeGen/GlobalISel/IRTranslator.h"
Index: llvm/lib/CodeGen/CommandFlags.cpp
===================================================================
--- llvm/lib/CodeGen/CommandFlags.cpp
+++ llvm/lib/CodeGen/CommandFlags.cpp
@@ -90,7 +90,7 @@
CGOPT(bool, EmitCallSiteInfo)
CGOPT(bool, EnableMachineFunctionSplitter)
CGOPT(bool, EnableDebugEntryValues)
-CGOPT(bool, ValueTrackingVariableLocations)
+CGOPT_EXP(bool, ValueTrackingVariableLocations)
CGOPT(bool, ForceDwarfFrameSection)
CGOPT(bool, XRayOmitFunctionIndex)
CGOPT(bool, DebugStrictDwarf)
@@ -534,12 +534,17 @@
Options.EmitAddrsig = getEnableAddrsig();
Options.EmitCallSiteInfo = getEmitCallSiteInfo();
Options.EnableDebugEntryValues = getEnableDebugEntryValues();
- Options.ValueTrackingVariableLocations = getValueTrackingVariableLocations();
Options.ForceDwarfFrameSection = getForceDwarfFrameSection();
Options.XRayOmitFunctionIndex = getXRayOmitFunctionIndex();
Options.DebugStrictDwarf = getDebugStrictDwarf();
Options.LoopAlignment = getAlignLoops();
+ if (auto Opt = getExplicitValueTrackingVariableLocations())
+ Options.ValueTrackingVariableLocations = *Opt;
+ else
+ Options.ValueTrackingVariableLocations =
+ getDefaultValueTrackingVariableLocations(TheTriple);
+
Options.MCOptions = mc::InitMCTargetOptionsFromFlags();
Options.ThreadModel = getThreadModel();
@@ -692,3 +697,9 @@
for (Function &F : M)
setFunctionAttributes(CPU, Features, F);
}
+
+bool codegen::getDefaultValueTrackingVariableLocations(const llvm::Triple &T) {
+ if (T.getArch() == llvm::Triple::x86_64)
+ return true;
+ return false;
+}
Index: llvm/include/llvm/CodeGen/CommandFlags.h
===================================================================
--- llvm/include/llvm/CodeGen/CommandFlags.h
+++ llvm/include/llvm/CodeGen/CommandFlags.h
@@ -130,6 +130,7 @@
bool getEnableDebugEntryValues();
bool getValueTrackingVariableLocations();
+Optional<bool> getExplicitValueTrackingVariableLocations();
bool getForceDwarfFrameSection();
@@ -170,6 +171,10 @@
/// Set function attributes of functions in Module M based on CPU,
/// Features, and command line flags.
void setFunctionAttributes(StringRef CPU, StringRef Features, Module &M);
+
+/// Should value-tracking variable locations / instruction referencing be
+/// enabled by default for this triple?
+bool getDefaultValueTrackingVariableLocations(const llvm::Triple &T);
} // namespace codegen
} // namespace llvm
Index: clang/include/clang/Driver/Options.td
===================================================================
--- clang/include/clang/Driver/Options.td
+++ clang/include/clang/Driver/Options.td
@@ -5180,10 +5180,6 @@
CodeGenOpts<"DebugPassManager">, DefaultFalse,
PosFlag<SetTrue, [], "Prints debug information for the new pass manager">,
NegFlag<SetFalse, [], "Disables debug printing for the new pass manager">>;
-def fexperimental_debug_variable_locations : Flag<["-"],
- "fexperimental-debug-variable-locations">,
- HelpText<"Use experimental new value-tracking variable locations">,
- MarshallingInfoFlag<CodeGenOpts<"ValueTrackingVariableLocations">>;
def fverify_debuginfo_preserve
: Flag<["-"], "fverify-debuginfo-preserve">,
HelpText<"Enable Debug Info Metadata preservation testing in "
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
