Improve the accuracy of variable ranges .debug_loc location lists.
For the following motivating example
bool c();
void f();
bool start() {
bool result = c();
if (!c()) {
result = false;
goto exit;
}
f();
result = true;
exit:
return result;
}
we would previously generate a single DW_AT_const_value(1) because
only the DBG_VALUE in the second-to-last basic block survived
codegen. This patch improves the heuristic used to determine when a
DBG_VALUE is available at the beginning of its variable's enclosing
lexical scope:
- Stop giving singular constants blanket permission to take over the
entire scope. There is still a special case for constants in the
function prologue that we also miight want to retire later.
- Use the lexical scope information to determine available-at-entry
instead of proximity to the function prologue.
After this patch we generate a location list with a more accurate
narrower availability for the constant true value. As a pleasant side
effect, we also generate inline locations instead of location lists
where a loacation covers the entire range of the enclosing lexical
scope.
Measured on compiling llc with four targets this doesn't have an
effect on compile time and reduces the size of the debug info for llc
by ~600K.
rdar://problem/30286912
llvm-svn: 305599
diff --git a/llvm/test/DebugInfo/Generic/partial-constant.ll b/llvm/test/DebugInfo/Generic/partial-constant.ll
new file mode 100644
index 0000000..c3abccb
--- /dev/null
+++ b/llvm/test/DebugInfo/Generic/partial-constant.ll
@@ -0,0 +1,82 @@
+; RUN: %llc_dwarf -filetype=obj < %s | llvm-dwarfdump - | FileCheck %s
+; Generated at -O2 from:
+; bool c();
+; void f();
+; bool start() {
+; bool result = c();
+; if (!c()) {
+; result = false;
+; goto exit;
+; }
+; f();
+; result = true;
+; exit:
+; return result;
+; }
+;
+; The constant should NOT be available for the entire function.
+; CHECK-NOT: DW_AT_const_value
+; CHECK: .debug_loc
+; CHECK: Location description: 10 01 9f
+; constu 0x00000001, stack-value
+source_filename = "test.ii"
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.12.0"
+
+; Function Attrs: noimplicitfloat noredzone nounwind optsize
+define zeroext i1 @_Z5startv() local_unnamed_addr #0 !dbg !7 {
+entry:
+ %call = tail call zeroext i1 @_Z1cv() #3, !dbg !13
+ %call1 = tail call zeroext i1 @_Z1cv() #3, !dbg !14
+ br i1 %call1, label %if.end, label %exit, !dbg !16
+
+if.end: ; preds = %entry
+ tail call void @_Z1fv() #3, !dbg !17
+ tail call void @llvm.dbg.value(metadata i8 1, i64 0, metadata !12, metadata !18), !dbg !19
+ br label %exit, !dbg !20
+
+exit: ; preds = %entry, %if.end
+ %result.0 = phi i1 [ true, %if.end ], [ false, %entry ]
+ ret i1 %result.0, !dbg !21
+}
+
+; Function Attrs: noimplicitfloat noredzone optsize
+declare zeroext i1 @_Z1cv() local_unnamed_addr #1
+
+; Function Attrs: noimplicitfloat noredzone optsize
+declare void @_Z1fv() local_unnamed_addr #1
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #2
+
+attributes #0 = { noimplicitfloat noredzone nounwind optsize }
+attributes #1 = { noimplicitfloat noredzone optsize }
+attributes #2 = { nounwind readnone speculatable }
+attributes #3 = { nobuiltin noimplicitfloat noredzone nounwind optsize }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 5.0.0 (trunk 303873) (llvm/trunk 303897)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "test.ii", directory: "/")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 5.0.0 (trunk 303873) (llvm/trunk 303897)"}
+!7 = distinct !DISubprogram(name: "start", linkageName: "_Z5startv", scope: !1, file: !1, line: 3, type: !8, isLocal: false, isDefinition: true, scopeLine: 3, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !11)
+!8 = !DISubroutineType(types: !9)
+!9 = !{!10}
+!10 = !DIBasicType(name: "bool", size: 8, encoding: DW_ATE_boolean)
+!11 = !{!12}
+!12 = !DILocalVariable(name: "result", scope: !7, file: !1, line: 4, type: !10)
+!13 = !DILocation(line: 4, column: 17, scope: !7)
+!14 = !DILocation(line: 5, column: 8, scope: !15)
+!15 = distinct !DILexicalBlock(scope: !7, file: !1, line: 5, column: 7)
+!16 = !DILocation(line: 5, column: 7, scope: !7)
+!17 = !DILocation(line: 9, column: 3, scope: !7)
+!18 = !DIExpression()
+!19 = !DILocation(line: 4, column: 8, scope: !7)
+!20 = !DILocation(line: 10, column: 3, scope: !7)
+!21 = !DILocation(line: 12, column: 3, scope: !7)
diff --git a/llvm/test/DebugInfo/Generic/sugared-constants.ll b/llvm/test/DebugInfo/Generic/sugared-constants.ll
index 2bee2a9..97d4d60 100644
--- a/llvm/test/DebugInfo/Generic/sugared-constants.ll
+++ b/llvm/test/DebugInfo/Generic/sugared-constants.ll
@@ -3,47 +3,23 @@
; RUN: %llc_dwarf -O0 -filetype=obj %s -o - | llvm-dwarfdump -debug-dump=info - | FileCheck %s
; Use correct signedness when emitting constants of derived (sugared) types.
-; Test compiled to IR from clang with -O1 and the following source:
-
-; void func(int);
-; void func(unsigned);
-; void func(char16_t);
-; int main() {
-; const int i = 42;
-; func(i);
-; const unsigned j = 117;
-; func(j);
-; char16_t c = 7;
-; func(c);
-; }
-
; CHECK: DW_AT_const_value [DW_FORM_sdata] (42)
; CHECK: DW_AT_const_value [DW_FORM_udata] (117)
; CHECK: DW_AT_const_value [DW_FORM_udata] (7)
; Function Attrs: uwtable
-define i32 @main() #0 !dbg !4 {
+define void @main() #0 !dbg !4 {
entry:
tail call void @llvm.dbg.value(metadata i32 42, i64 0, metadata !10, metadata !DIExpression()), !dbg !21
- tail call void @_Z4funci(i32 42), !dbg !22
tail call void @llvm.dbg.value(metadata i32 117, i64 0, metadata !12, metadata !DIExpression()), !dbg !24
- tail call void @_Z4funcj(i32 117), !dbg !25
tail call void @llvm.dbg.value(metadata i16 7, i64 0, metadata !15, metadata !DIExpression()), !dbg !27
- tail call void @_Z4funcDs(i16 zeroext 7), !dbg !28
- ret i32 0, !dbg !29
+ ret void, !dbg !29
}
-declare void @_Z4funci(i32) #1
-
-declare void @_Z4funcj(i32) #1
-
-declare void @_Z4funcDs(i16 zeroext) #1
-
; Function Attrs: nounwind readnone
declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #2
-attributes #0 = { uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
-attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #0 = { uwtable }
attributes #2 = { nounwind readnone }
!llvm.dbg.cu = !{!0}
diff --git a/llvm/test/DebugInfo/MIR/X86/bit-piece-dh.mir b/llvm/test/DebugInfo/MIR/X86/bit-piece-dh.mir
index 34a10bd..d4b897e 100644
--- a/llvm/test/DebugInfo/MIR/X86/bit-piece-dh.mir
+++ b/llvm/test/DebugInfo/MIR/X86/bit-piece-dh.mir
@@ -1,13 +1,9 @@
-# RUN: llc -filetype=obj -o - %s | llvm-dwarfdump - | FileCheck %s
+# RUN: llc -filetype=obj -o - %s | llvm-dwarfdump --debug-dump=info - | FileCheck %s
# CHECK: .debug_info contents:
# CHECK: DW_TAG_variable
-# CHECK-NEXT: DW_AT_location [DW_FORM_sec_offset] ([[OFS:.*]])
-# CHECK-NEXT: DW_AT_name {{.*}}"dh"
-# CHECK: .debug_loc contents:
-# CHECK: [[OFS]]: Beginning address offset: 0x0000000000000002
-# CHECK: Ending address offset: 0x000000000000000c
-# CHECK: Location description: 51 9d 08 08
# rdx, bit-piece 8 8
+# CHECK-NEXT: DW_AT_location {{.*}} 51 9d 08 08
+# CHECK-NEXT: DW_AT_name {{.*}}"dh"
--- |
; Manually created after:
; char f(int i) {
diff --git a/llvm/test/DebugInfo/X86/dbg-merge-loc-entry.ll b/llvm/test/DebugInfo/X86/dbg-merge-loc-entry.ll
index 17fd0d5..272ee0b 100644
--- a/llvm/test/DebugInfo/X86/dbg-merge-loc-entry.ll
+++ b/llvm/test/DebugInfo/X86/dbg-merge-loc-entry.ll
@@ -6,6 +6,7 @@
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
target triple = "x86_64-apple-darwin8"
+; Test that consecutive, identical DBG_VALUEs are merged.
;CHECK: DW_AT_location{{.*}}(<0x1> 55 )
%0 = type { i64, i1 }
@@ -19,6 +20,7 @@
br i1 undef, label %bb2, label %bb4, !dbg !22
bb2: ; preds = %entry
+ tail call void @llvm.dbg.value(metadata i128 %u, i64 0, metadata !14, metadata !DIExpression()), !dbg !15
br label %bb4, !dbg !23
bb4: ; preds = %bb2, %entry
diff --git a/llvm/test/DebugInfo/X86/inlined-formal-parameter.ll b/llvm/test/DebugInfo/X86/inlined-formal-parameter.ll
index 78dc905..3b603c9 100644
--- a/llvm/test/DebugInfo/X86/inlined-formal-parameter.ll
+++ b/llvm/test/DebugInfo/X86/inlined-formal-parameter.ll
@@ -1,5 +1,5 @@
; RUN: llc -filetype=obj -o %t.o %s
-; RUN: llvm-dwarfdump -debug-dump=info %t.o | FileCheck %s
+; RUN: llvm-dwarfdump %t.o | FileCheck %s
; Testcase generated using 'clang -g -O2 -S -emit-llvm' from the following:
;; void sink(void);
@@ -10,6 +10,7 @@
;; }
; Check that we have formal parameters for 'a' in both inlined subroutines.
+; CHECK: .debug_info
; CHECK: DW_TAG_inlined_subroutine
; CHECK-NEXT: DW_AT_abstract_origin {{.*}} "bar"
; CHECK: DW_TAG_formal_parameter
@@ -18,9 +19,11 @@
; CHECK: DW_TAG_inlined_subroutine
; CHECK-NEXT: DW_AT_abstract_origin {{.*}} "bar"
; CHECK: DW_TAG_formal_parameter
-; CHECK-NEXT: DW_AT_const_value
+; CHECK-NEXT: DW_AT_location [DW_FORM_data4] (0x00000000)
; CHECK-NEXT: DW_AT_abstract_origin {{.*}} "a"
-
+;
+; CHECK: .debug_loc
+; CHECK: Location description: 11 00
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-apple-darwin"
@@ -34,13 +37,12 @@
ret void, !dbg !24
}
-declare void @sink() #1
+declare void @sink()
; Function Attrs: nounwind readnone
declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #2
-attributes #0 = { nounwind ssp uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="core2" "unsafe-fp-math"="false" "use-soft-float"="false" }
-attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="core2" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #0 = { nounwind ssp uwtable }
attributes #2 = { nounwind readnone }
attributes #3 = { nounwind }
diff --git a/llvm/test/DebugInfo/X86/parameters.ll b/llvm/test/DebugInfo/X86/parameters.ll
index a8494f9..26fb82d 100644
--- a/llvm/test/DebugInfo/X86/parameters.ll
+++ b/llvm/test/DebugInfo/X86/parameters.ll
@@ -24,8 +24,9 @@
; CHECK: debug_info contents
; 0x74 is DW_OP_breg4, showing that the parameter is accessed indirectly
-; (with a zero offset) from the register parameter
-; CHECK: DW_AT_location [DW_FORM_data4] ([[F_LOC:0x[0-9]*]])
+; (with a zero offset) from the register parameter.
+; CHECK: DW_AT_location {{.*}} 74 00 06
+
; CHECK-NOT: DW_TAG
; CHECK: DW_AT_name{{.*}} = "f"
;
@@ -34,9 +35,6 @@
; CHECK: DW_AT_name{{.*}} = "g"
;
; CHECK: debug_loc contents
-; CHECK: [[F_LOC]]: Beginning
-; CHECK-NEXT: Ending
-; CHECK-NEXT: Location description: 74 00
; CHECK: [[G_LOC]]: Beginning
; CHECK-NEXT: Ending
; CHECK-NEXT: Location description: 74 00
@@ -77,11 +75,10 @@
ret void, !dbg !32
}
-declare void @_ZN7pr147634sinkEPv(i8*) #2
+declare void @_ZN7pr147634sinkEPv(i8*)
-attributes #0 = { uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf"="true" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #0 = { uwtable }
attributes #1 = { nounwind readnone }
-attributes #2 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf"="true" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false" "use-soft-float"="false" }
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!21, !33}
diff --git a/llvm/test/DebugInfo/X86/pieces-3.ll b/llvm/test/DebugInfo/X86/pieces-3.ll
index fd5a8b8..0f80f71 100644
--- a/llvm/test/DebugInfo/X86/pieces-3.ll
+++ b/llvm/test/DebugInfo/X86/pieces-3.ll
@@ -19,7 +19,9 @@
; CHECK-NEXT: DW_AT_location [DW_FORM_data4] ([[LOC1:.*]])
; CHECK-NEXT: DW_AT_name {{.*}}"outer"
; CHECK: DW_TAG_variable
-; CHECK-NEXT: DW_AT_location [DW_FORM_data4] ([[LOC2:.*]])
+; CHECK-NEXT: DW_AT_location
+; rsi, piece 0x00000004
+; CHECK-SAME: 54 93 04
; CHECK-NEXT: "i1"
;
; CHECK: .debug_loc
@@ -32,10 +34,6 @@
; CHECK: Beginning address offset: 0x0000000000000004
; CHECK-NEXT: Ending address offset: 0x0000000000000008
; CHECK-NEXT: Location description: 55 93 08 93 04 54 93 04
-; CHECK: [[LOC2]]: Beginning address offset: 0x0000000000000004
-; CHECK-NEXT: Ending address offset: 0x0000000000000008
-; rsi, piece 0x00000004
-; CHECK-NEXT: Location description: 54 93 04
;
; ModuleID = '/Volumes/Data/llvm/test/DebugInfo/X86/sroasplit-2.ll'
@@ -48,6 +46,7 @@
call void @llvm.dbg.declare(metadata !{null}, metadata !27, metadata !28), !dbg !26
call void @llvm.dbg.value(metadata i64 %outer.coerce1, i64 0, metadata !29, metadata !30), !dbg !26
call void @llvm.dbg.declare(metadata !{null}, metadata !31, metadata !32), !dbg !26
+ ; The 'trunc' generates no extra code, thus i1 is visible throughout its scope.
%outer.sroa.1.8.extract.trunc = trunc i64 %outer.coerce1 to i32, !dbg !33
call void @llvm.dbg.value(metadata i32 %outer.sroa.1.8.extract.trunc, i64 0, metadata !34, metadata !35), !dbg !33
%outer.sroa.1.12.extract.shift = lshr i64 %outer.coerce1, 32, !dbg !33
diff --git a/llvm/test/DebugInfo/X86/reference-argument.ll b/llvm/test/DebugInfo/X86/reference-argument.ll
index 52e9290..4b8caa1 100644
--- a/llvm/test/DebugInfo/X86/reference-argument.ll
+++ b/llvm/test/DebugInfo/X86/reference-argument.ll
@@ -1,4 +1,5 @@
-; RUN: llc -mtriple=x86_64-apple-macosx10.9.0 -filetype=obj -O0 < %s | llvm-dwarfdump -debug-dump=all - | FileCheck %s
+; RUN: llc -mtriple=x86_64-apple-macosx10.9.0 -filetype=obj -O0 < %s \
+; RUN: | llvm-dwarfdump -debug-dump=info - | FileCheck %s
; ModuleID = 'aggregate-indirect-arg.cpp'
; extracted from debuginfo-tests/aggregate-indirect-arg.cpp
@@ -11,11 +12,10 @@
; CHECK: DW_AT_name {{.*}} "this"
; CHECK-NOT: DW_TAG_subprogram
; CHECK: DW_TAG_formal_parameter
-; CHECK-NEXT: DW_AT_location [DW_FORM_data4] (0x00000000)
-; CHECK-NEXT: DW_AT_name {{.*}} "v"
-; CHECK: .debug_loc contents:
+; CHECK-NEXT: DW_AT_location
; rsi+0
-; CHECK: Location description: 74 00
+; CHECK-SAME: 74 00
+; CHECK-NEXT: DW_AT_name {{.*}} "v"
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.9.0"
diff --git a/llvm/test/DebugInfo/X86/this-stack_value.ll b/llvm/test/DebugInfo/X86/this-stack_value.ll
index c292b67..6ea96c2 100644
--- a/llvm/test/DebugInfo/X86/this-stack_value.ll
+++ b/llvm/test/DebugInfo/X86/this-stack_value.ll
@@ -1,5 +1,5 @@
; RUN: llc -filetype=asm -o - %s | FileCheck %s --check-prefix=ASM
-; RUN: llc -filetype=obj -o - %s | llvm-dwarfdump - | FileCheck %s
+; RUN: llc -filetype=obj -o - %s | llvm-dwarfdump --debug-dump=info - | FileCheck %s
;
; Generated at -O2 from:
; struct B;
@@ -18,7 +18,7 @@
; modified by the debugger.
;
; ASM: [DW_OP_stack_value]
-; CHECK: Location description: 70 00 9f
+; CHECK: DW_AT_location {{.*}} 70 00 9f
; rax+0, stack-value
source_filename = "ab.cpp"
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"