[llvm] r211609 - Add new debug kind LocTrackingOnly.
Diego Novillo
dnovillo at google.com
Tue Jun 24 10:02:04 PDT 2014
Author: dnovillo
Date: Tue Jun 24 12:02:03 2014
New Revision: 211609
URL: http://llvm.org/viewvc/llvm-project?rev=211609&view=rev
Log:
Add new debug kind LocTrackingOnly.
Summary:
This new debug emission kind supports emitting line location
information in all instructions, but stops code generation
from emitting debug info to the final output.
This mode is useful when the backend wants to track source
locations during code generation, but it does not want to
produce debug info. This is currently used by optimization
remarks (-pass-remarks, -pass-remarks-missed and
-pass-remarks-analysis).
To prevent debug info emission, DIBuilder never inserts the
annotation 'llvm.dbg.cu' when LocTrackingOnly is enabled.
Reviewers: echristo, dblaikie
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D4234
Modified:
llvm/trunk/include/llvm/IR/DIBuilder.h
llvm/trunk/lib/IR/DIBuilder.cpp
llvm/trunk/test/Transforms/LoopVectorize/X86/vectorization-remarks.ll
Modified: llvm/trunk/include/llvm/IR/DIBuilder.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/DIBuilder.h?rev=211609&r1=211608&r2=211609&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/DIBuilder.h (original)
+++ llvm/trunk/include/llvm/IR/DIBuilder.h Tue Jun 24 12:02:03 2014
@@ -108,12 +108,23 @@ namespace llvm {
/// Objective-C.
/// @param SplitName The name of the file that we'll split debug info out
/// into.
+ /// @param Kind The kind of debug information to generate.
+ /// @param EmitDebugInfo A boolean flag which indicates whether debug
+ /// information should be written to the final
+ /// output or not. When this is false, debug
+ /// information annotations will be present in
+ /// the IL but they are not written to the final
+ /// assembly or object file. This supports tracking
+ /// source location information in the back end
+ /// without actually changing the output (e.g.,
+ /// when using optimization remarks).
DICompileUnit createCompileUnit(unsigned Lang, StringRef File,
StringRef Dir, StringRef Producer,
bool isOptimized, StringRef Flags,
unsigned RV,
StringRef SplitName = StringRef(),
- DebugEmissionKind Kind = FullDebug);
+ DebugEmissionKind Kind = FullDebug,
+ bool EmitDebugInfo = true);
/// createFile - Create a file descriptor to hold debugging information
/// for a file.
Modified: llvm/trunk/lib/IR/DIBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/DIBuilder.cpp?rev=211609&r1=211608&r2=211609&view=diff
==============================================================================
--- llvm/trunk/lib/IR/DIBuilder.cpp (original)
+++ llvm/trunk/lib/IR/DIBuilder.cpp Tue Jun 24 12:02:03 2014
@@ -102,7 +102,8 @@ DICompileUnit DIBuilder::createCompileUn
StringRef Producer, bool isOptimized,
StringRef Flags, unsigned RunTimeVer,
StringRef SplitName,
- DebugEmissionKind Kind) {
+ DebugEmissionKind Kind,
+ bool EmitDebugInfo) {
assert(((Lang <= dwarf::DW_LANG_OCaml && Lang >= dwarf::DW_LANG_C89) ||
(Lang <= dwarf::DW_LANG_hi_user && Lang >= dwarf::DW_LANG_lo_user)) &&
@@ -140,8 +141,14 @@ DICompileUnit DIBuilder::createCompileUn
MDNode *CUNode = MDNode::get(VMContext, Elts);
// Create a named metadata so that it is easier to find cu in a module.
- NamedMDNode *NMD = M.getOrInsertNamedMetadata("llvm.dbg.cu");
- NMD->addOperand(CUNode);
+ // Note that we only generate this when the caller wants to actually
+ // emit debug information. When we are only interested in tracking
+ // source line locations throughout the backend, we prevent codegen from
+ // emitting debug info in the final output by not generating llvm.dbg.cu.
+ if (EmitDebugInfo) {
+ NamedMDNode *NMD = M.getOrInsertNamedMetadata("llvm.dbg.cu");
+ NMD->addOperand(CUNode);
+ }
return DICompileUnit(CUNode);
}
Modified: llvm/trunk/test/Transforms/LoopVectorize/X86/vectorization-remarks.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopVectorize/X86/vectorization-remarks.ll?rev=211609&r1=211608&r2=211609&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LoopVectorize/X86/vectorization-remarks.ll (original)
+++ llvm/trunk/test/Transforms/LoopVectorize/X86/vectorization-remarks.ll Tue Jun 24 12:02:03 2014
@@ -1,6 +1,13 @@
; RUN: opt < %s -loop-vectorize -mtriple=x86_64-unknown-linux -S -pass-remarks='loop-vectorize' 2>&1 | FileCheck -check-prefix=VECTORIZED %s
; RUN: opt < %s -loop-vectorize -force-vector-width=1 -force-vector-unroll=4 -mtriple=x86_64-unknown-linux -S -pass-remarks='.*vectorize.*' 2>&1 | FileCheck -check-prefix=UNROLLED %s
+; This code has all the !dbg annotations needed to track source line information,
+; but is missing the llvm.dbg.cu annotation. This prevents code generation from
+; emitting debug info in the final output.
+; RUN: llc -mtriple x86_64-pc-linux-gnu %s -o - | FileCheck -check-prefix=DEBUG-OUTPUT %s
+; DEBUG-OUTPUT-NOT: .loc
+; DEBUG-OUTPUT-NOT: {{.*}}.debug_info
+
; VECTORIZED: remark: {{.*}}.c:17:8: vectorized loop (vectorization factor: 4, unrolling interleave factor: 1)
; UNROLLED: remark: {{.*}}.c:17:8: unrolled with interleaving factor 4 (vectorization not beneficial)
@@ -37,11 +44,9 @@ for.end:
declare void @ibar(i32*) #1
-!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!7, !8}
!llvm.ident = !{!9}
-!0 = metadata !{i32 786449, metadata !1, i32 12, metadata !"clang version 3.5.0 ", i1 true, metadata !"", i32 0, metadata !2, metadata !2, metadata !3, metadata !2, metadata !2, metadata !"", i32 2} ; [ DW_TAG_compile_unit ] [./vectorization-remarks.c] [DW_LANG_C99]
!1 = metadata !{metadata !"vectorization-remarks.c", metadata !"."}
!2 = metadata !{}
!3 = metadata !{metadata !4}
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