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JDevlieghereJDevlieghere
committedSep 5, 2018
[DebugInfo] Normalize common kinds of DWARF sub-expressions.
Normalize common kinds of DWARF sub-expressions to make debug info encoding a bit more compact: DW_OP_constu [X < 32] -> DW_OP_litX DW_OP_constu [all ones] -> DW_OP_lit0, DW_OP_not (64-bit only) Differential revision: https://reviews.llvm.org/D51640 llvm-svn: 341457
·
llvmorg-21-initllvmorg-8.0.0-rc1
1 parent e157cea commit 965b598

14 files changed

+61
-49
lines changed
 

‎llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp

+18-8
Original file line numberDiff line numberDiff line change
@@ -24,6 +24,20 @@
2424

2525
using namespace llvm;
2626

27+
void DwarfExpression::emitConstu(uint64_t Value) {
28+
if (Value < 32)
29+
emitOp(dwarf::DW_OP_lit0 + Value);
30+
else if (Value == std::numeric_limits<uint64_t>::max()) {
31+
// Only do this for 64-bit values as the DWARF expression stack uses
32+
// target-address-size values.
33+
emitOp(dwarf::DW_OP_lit0);
34+
emitOp(dwarf::DW_OP_not);
35+
} else {
36+
emitOp(dwarf::DW_OP_constu);
37+
emitUnsigned(Value);
38+
}
39+
}
40+
2741
void DwarfExpression::addReg(int DwarfReg, const char *Comment) {
2842
assert(DwarfReg >= 0 && "invalid negative dwarf register number");
2943
assert((LocationKind == Unknown || LocationKind == Register) &&
@@ -72,14 +86,12 @@ void DwarfExpression::addOpPiece(unsigned SizeInBits, unsigned OffsetInBits) {
7286
}
7387

7488
void DwarfExpression::addShr(unsigned ShiftBy) {
75-
emitOp(dwarf::DW_OP_constu);
76-
emitUnsigned(ShiftBy);
89+
emitConstu(ShiftBy);
7790
emitOp(dwarf::DW_OP_shr);
7891
}
7992

8093
void DwarfExpression::addAnd(unsigned Mask) {
81-
emitOp(dwarf::DW_OP_constu);
82-
emitUnsigned(Mask);
94+
emitConstu(Mask);
8395
emitOp(dwarf::DW_OP_and);
8496
}
8597

@@ -181,8 +193,7 @@ void DwarfExpression::addSignedConstant(int64_t Value) {
181193
void DwarfExpression::addUnsignedConstant(uint64_t Value) {
182194
assert(LocationKind == Implicit || LocationKind == Unknown);
183195
LocationKind = Implicit;
184-
emitOp(dwarf::DW_OP_constu);
185-
emitUnsigned(Value);
196+
emitConstu(Value);
186197
}
187198

188199
void DwarfExpression::addUnsignedConstant(const APInt &Value) {
@@ -373,8 +384,7 @@ void DwarfExpression::addExpression(DIExpressionCursor &&ExprCursor,
373384
break;
374385
case dwarf::DW_OP_constu:
375386
assert(LocationKind != Register);
376-
emitOp(dwarf::DW_OP_constu);
377-
emitUnsigned(Op->getArg(0));
387+
emitConstu(Op->getArg(0));
378388
break;
379389
case dwarf::DW_OP_stack_value:
380390
LocationKind = Implicit;

‎llvm/lib/CodeGen/AsmPrinter/DwarfExpression.h

+3
Original file line numberDiff line numberDiff line change
@@ -138,6 +138,9 @@ class DwarfExpression {
138138
/// Emit a raw unsigned value.
139139
virtual void emitUnsigned(uint64_t Value) = 0;
140140

141+
/// Emit a normalized unsigned constant.
142+
void emitConstu(uint64_t Value);
143+
141144
/// Return whether the given machine register is the frame register in the
142145
/// current function.
143146
virtual bool isFrameRegister(const TargetRegisterInfo &TRI, unsigned MachineReg) = 0;

‎llvm/test/DebugInfo/AMDGPU/variable-locations.ll

+3-3
Original file line numberDiff line numberDiff line change
@@ -36,15 +36,15 @@ declare void @llvm.dbg.declare(metadata, metadata, metadata)
3636

3737
define amdgpu_kernel void @kernel1(
3838
; CHECK: {{.*}}DW_TAG_formal_parameter
39-
; CHECK-NEXT: DW_AT_location [DW_FORM_block1] (DW_OP_fbreg +4, DW_OP_constu 0x1, DW_OP_swap, DW_OP_xderef)
39+
; CHECK-NEXT: DW_AT_location [DW_FORM_block1] (DW_OP_fbreg +4, DW_OP_lit1, DW_OP_swap, DW_OP_xderef)
4040
; CHECK-NEXT: DW_AT_name {{.*}}"ArgN"
4141
i32 %ArgN,
4242
; CHECK: {{.*}}DW_TAG_formal_parameter
43-
; CHECK-NEXT: DW_AT_location [DW_FORM_block1] (DW_OP_fbreg +8, DW_OP_constu 0x1, DW_OP_swap, DW_OP_xderef)
43+
; CHECK-NEXT: DW_AT_location [DW_FORM_block1] (DW_OP_fbreg +8, DW_OP_lit1, DW_OP_swap, DW_OP_xderef)
4444
; CHECK-NEXT: DW_AT_name {{.*}}"ArgA"
4545
i32 addrspace(1)* %ArgA,
4646
; CHECK: {{.*}}DW_TAG_formal_parameter
47-
; CHECK-NEXT: DW_AT_location [DW_FORM_block1] (DW_OP_fbreg +16, DW_OP_constu 0x1, DW_OP_swap, DW_OP_xderef)
47+
; CHECK-NEXT: DW_AT_location [DW_FORM_block1] (DW_OP_fbreg +16, DW_OP_lit1, DW_OP_swap, DW_OP_xderef)
4848
; CHECK-NEXT: DW_AT_name {{.*}}"ArgB"
4949
i32 addrspace(1)* %ArgB) !dbg !13 {
5050
entry:

‎llvm/test/DebugInfo/ARM/PR26163.ll

+2-2
Original file line numberDiff line numberDiff line change
@@ -9,8 +9,8 @@
99
; CHECK: DW_TAG_inlined_subroutine
1010
; CHECK: DW_TAG_variable
1111
; CHECK: DW_AT_location [DW_FORM_sec_offset] ({{.*}}
12-
; CHECK: [0x00000004, 0x00000004): DW_OP_constu 0x0, DW_OP_stack_value, DW_OP_piece 0x8
13-
; CHECK: [0x00000004, 0x00000014): DW_OP_constu 0x0, DW_OP_stack_value, DW_OP_piece 0x4)
12+
; CHECK: [0x00000004, 0x00000004): DW_OP_lit0, DW_OP_stack_value, DW_OP_piece 0x8
13+
; CHECK: [0x00000004, 0x00000014): DW_OP_lit0, DW_OP_stack_value, DW_OP_piece 0x4)
1414

1515
; Created form the following test case (PR26163) with
1616
; clang -cc1 -triple armv4t--freebsd11.0-gnueabi -emit-obj -debug-info-kind=standalone -O2 -x c test.c

‎llvm/test/DebugInfo/ARM/split-complex.ll

+1-1
Original file line numberDiff line numberDiff line change
@@ -14,7 +14,7 @@ entry:
1414
; The target has no native double type.
1515
; SROA split the complex value into two i64 values.
1616
; CHECK: DW_TAG_formal_parameter
17-
; CHECK-NEXT: DW_AT_location [DW_FORM_block1] (DW_OP_constu 0x0, DW_OP_piece 0x8)
17+
; CHECK-NEXT: DW_AT_location [DW_FORM_block1] (DW_OP_lit0, DW_OP_piece 0x8)
1818
; CHECK-NEXT: DW_AT_name {{.*}} "c"
1919
tail call void @llvm.dbg.value(metadata i64 0, metadata !14, metadata !17), !dbg !16
2020
; Manually removed to disable location list emission:

‎llvm/test/DebugInfo/Generic/incorrect-variable-debugloc1.ll

+6-5
Original file line numberDiff line numberDiff line change
@@ -1,6 +1,6 @@
11
; REQUIRES: object-emission
22
; This test is failing for powerpc64, because a location list for the
3-
; variable 'c' is not generated at all. Temporary marking this test as XFAIL
3+
; variable 'c' is not generated at all. Temporary marking this test as XFAIL
44
; for powerpc, until PR21881 is fixed.
55
; XFAIL: powerpc64
66

@@ -9,13 +9,14 @@
99
; RUN: %llc_dwarf -O2 -dwarf-version 4 -filetype=obj < %s | llvm-dwarfdump - | FileCheck %s --check-prefix=DWARF4
1010

1111
; This is a test for PR21176.
12-
; DW_OP_const <const> doesn't describe a constant value, but a value at a constant address.
12+
; DW_OP_const <const> doesn't describe a constant value, but a value at a constant address.
1313
; The proper way to describe a constant value is DW_OP_constu <const>, DW_OP_stack_value.
14+
; For values < 32 we emit the canonical DW_OP_lit<const>.
1415

1516
; Generated with clang -S -emit-llvm -g -O2 test.cpp
1617

1718
; extern int func();
18-
;
19+
;
1920
; int main()
2021
; {
2122
; volatile int c = 13;
@@ -26,8 +27,8 @@
2627
; CHECK: DW_TAG_variable
2728
; CHECK: DW_AT_location
2829
; CHECK-NOT: DW_AT
29-
; DWARF23: DW_OP_constu 0xd{{$}}
30-
; DWARF4: DW_OP_constu 0xd, DW_OP_stack_value{{$}}
30+
; DWARF23: DW_OP_lit13{{$}}
31+
; DWARF4: DW_OP_lit13, DW_OP_stack_value{{$}}
3132

3233
; Function Attrs: uwtable
3334
define i32 @main() #0 !dbg !4 {

‎llvm/test/DebugInfo/X86/PR26148.ll

+2-2
Original file line numberDiff line numberDiff line change
@@ -19,8 +19,8 @@
1919
; AS in 26163, we expect two ranges (as opposed to one), the first one being zero sized
2020
;
2121
;
22-
; CHECK: [0x0000000000000004, 0x0000000000000004): DW_OP_constu 0x3, DW_OP_piece 0x4, DW_OP_reg5 RDI, DW_OP_piece 0x2
23-
; CHECK: [0x0000000000000004, 0x0000000000000014): DW_OP_constu 0x3, DW_OP_piece 0x4, DW_OP_constu 0x0, DW_OP_piece 0x4
22+
; CHECK: [0x0000000000000004, 0x0000000000000004): DW_OP_lit3, DW_OP_piece 0x4, DW_OP_reg5 RDI, DW_OP_piece 0x2
23+
; CHECK: [0x0000000000000004, 0x0000000000000014): DW_OP_lit3, DW_OP_piece 0x4, DW_OP_lit0, DW_OP_piece 0x4
2424

2525
source_filename = "test/DebugInfo/X86/PR26148.ll"
2626
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"

‎llvm/test/DebugInfo/X86/constant-loclist.ll

+1-1
Original file line numberDiff line numberDiff line change
@@ -14,7 +14,7 @@
1414
; CHECK-NEXT: DW_AT_name {{.*}}"i"
1515
; CHECK: DW_TAG_variable
1616
; CHECK-NEXT: DW_AT_location [DW_FORM_data4] (
17-
; CHECK-NEXT: [0x{{.*}}, 0x{{.*}}): DW_OP_constu 0x0
17+
; CHECK-NEXT: [0x{{.*}}, 0x{{.*}}): DW_OP_lit0
1818
; CHECK-NEXT: [0x{{.*}}, 0x{{.*}}): DW_OP_constu 0x4000000000000000)
1919
; CHECK-NEXT: DW_AT_name {{.*}}"u"
2020

‎llvm/test/DebugInfo/X86/dw_op_minus_direct.ll

+1-1
Original file line numberDiff line numberDiff line change
@@ -17,7 +17,7 @@
1717

1818
; CHECK: .debug_loc contents:
1919
; CHECK: 0x00000000:
20-
; CHECK-NEXT: [0x0000000000000000, 0x0000000000000004): DW_OP_breg0 RAX+0, DW_OP_constu 0xffffffff, DW_OP_and, DW_OP_constu 0x1, DW_OP_minus, DW_OP_stack_value
20+
; CHECK-NEXT: [0x0000000000000000, 0x0000000000000004): DW_OP_breg0 RAX+0, DW_OP_constu 0xffffffff, DW_OP_and, DW_OP_lit1, DW_OP_minus, DW_OP_stack_value
2121
; rax+0, constu 0xffffffff, and, constu 0x00000001, minus, stack-value
2222

2323
source_filename = "minus.c"

‎llvm/test/DebugInfo/X86/partial-constant.ll

+1-1
Original file line numberDiff line numberDiff line change
@@ -18,7 +18,7 @@
1818
; CHECK-NOT: DW_AT_const_value
1919
; CHECK: .debug_loc contents:
2020
; CHECK-NEXT: 0x00000000:
21-
; CHECK-NEXT: {{.*}}: DW_OP_constu 0x1, DW_OP_stack_value
21+
; CHECK-NEXT: {{.*}}: DW_OP_lit1, DW_OP_stack_value
2222

2323
source_filename = "test.ii"
2424
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"

‎llvm/test/DebugInfo/X86/pieces-4.ll

+1-1
Original file line numberDiff line numberDiff line change
@@ -25,7 +25,7 @@
2525

2626
; DWARF: .debug_loc contents:
2727
; DWARF-NEXT: 0x00000000:
28-
; DWARF-NEXT: {{.*}}: DW_OP_breg7 RSP+{{[0-9]+}}, DW_OP_piece 0x4, DW_OP_constu 0x0, DW_OP_stack_value, DW_OP_piece 0x4
28+
; DWARF-NEXT: {{.*}}: DW_OP_breg7 RSP+{{[0-9]+}}, DW_OP_piece 0x4, DW_OP_lit0, DW_OP_stack_value, DW_OP_piece 0x4
2929

3030
; ModuleID = 't.c'
3131
source_filename = "t.c"

‎llvm/test/DebugInfo/X86/split-global.ll

+2-2
Original file line numberDiff line numberDiff line change
@@ -17,13 +17,13 @@ target triple = "x86_64-apple-macosx10.12.0"
1717
; CHECK: DW_TAG_variable
1818
; CHECK-NEXT: DW_AT_name {{.*}}"part_const"
1919
; CHECK-NOT: DW_TAG
20-
; CHECK: DW_AT_location [DW_FORM_exprloc] (DW_OP_addr 0x8, DW_OP_piece 0x4, DW_OP_constu 0x2, DW_OP_stack_value, DW_OP_piece 0x4)
20+
; CHECK: DW_AT_location [DW_FORM_exprloc] (DW_OP_addr 0x8, DW_OP_piece 0x4, DW_OP_lit2, DW_OP_stack_value, DW_OP_piece 0x4)
2121
; [0x0000000000000008], piece 0x00000004, constu 0x00000002, stack-value, piece 0x00000004
2222
; CHECK-NOT: DW_TAG
2323
; CHECK: DW_TAG_variable
2424
; CHECK-NEXT: DW_AT_name {{.*}}"full_const"
2525
; CHECK-NOT: DW_TAG
26-
; CHECK: DW_AT_location [DW_FORM_exprloc] (DW_OP_constu 0x1, DW_OP_stack_value, DW_OP_piece 0x4, DW_OP_constu 0x2, DW_OP_stack_value, DW_OP_piece 0x4)
26+
; CHECK: DW_AT_location [DW_FORM_exprloc] (DW_OP_lit1, DW_OP_stack_value, DW_OP_piece 0x4, DW_OP_lit2, DW_OP_stack_value, DW_OP_piece 0x4)
2727
; CHECK-NOT: DW_TAG
2828
@point.y = global i32 2, align 4, !dbg !13
2929
@point.x = global i32 1, align 4, !dbg !12

‎llvm/test/DebugInfo/X86/stack-value-dwarf4.ll

+16-18
Original file line numberDiff line numberDiff line change
@@ -6,25 +6,23 @@
66
target datalayout = "e-p:64:64"
77
target triple = "x86_64-unknown-linux-gnu"
88

9-
; CHECK-DWARF2: .byte 8 # DW_AT_location
10-
; CHECK-DWARF2 .byte 16
11-
; CHECK-DWARF2 .byte 4
12-
; CHECK-DWARF2 .byte 147
13-
; CHECK-DWARF2 .byte 2
14-
; CHECK-DWARF2 .byte 16
15-
; CHECK-DWARF2 .byte 0
16-
; CHECK-DWARF2 .byte 147
17-
; CHECK-DWARF2 .byte 2
9+
; CHECK-DWARF2: .byte 6 # DW_AT_location
10+
; CHECK-DWARF2-NEXT: .byte 52
11+
; CHECK-DWARF2-NEXT: .byte 147
12+
; CHECK-DWARF2-NEXT: .byte 2
13+
; CHECK-DWARF2-NEXT: .byte 48
14+
; CHECK-DWARF2-NEXT: .byte 147
15+
; CHECK-DWARF2-NEXT: .byte 2
1816

19-
; CHECK-DWARF4: .byte 10 # DW_AT_location
20-
; CHECK-DWARF4-NEXT: .byte 16
21-
; CHECK-DWARF4-NEXT: .byte 4
22-
; CHECK-DWARF4-NEXT: .byte 159
23-
; CHECK-DWARF4-NEXT: .byte 147
24-
; CHECK-DWARF4-NEXT: .byte 2
25-
; CHECK-DWARF4-NEXT: .byte 16
26-
; CHECK-DWARF4-NEXT: .byte 0
27-
; CHECK-DWARF4-NEXT: .byte 159
17+
; CHECK-DWARF4: .byte 8 # DW_AT_location
18+
; CHECK-DWARF4-NEXT:.byte 52
19+
; CHECK-DWARF4-NEXT:.byte 159
20+
; CHECK-DWARF4-NEXT:.byte 147
21+
; CHECK-DWARF4-NEXT:.byte 2
22+
; CHECK-DWARF4-NEXT:.byte 48
23+
; CHECK-DWARF4-NEXT:.byte 159
24+
; CHECK-DWARF4-NEXT:.byte 147
25+
; CHECK-DWARF4-NEXT:.byte 2
2826

2927
!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, producer: "clang", file: !4, globals: !1, emissionKind: FullDebug)
3028
!1 = !{!2, !10}

‎llvm/test/DebugInfo/X86/stack-value-piece.ll

+4-4
Original file line numberDiff line numberDiff line change
@@ -19,21 +19,21 @@
1919
; CHECK: DW_AT_name {{.*}} "i"
2020
; CHECK: DW_TAG_variable
2121
; CHECK-NEXT: DW_AT_location {{.*}} ([[I:.*]]
22-
; CHECK-NEXT: [{{.*}}, {{.*}}): DW_OP_reg5 RDI, DW_OP_piece 0x4, DW_OP_constu 0x0, DW_OP_stack_value, DW_OP_piece 0x4)
22+
; CHECK-NEXT: [{{.*}}, {{.*}}): DW_OP_reg5 RDI, DW_OP_piece 0x4, DW_OP_lit0, DW_OP_stack_value, DW_OP_piece 0x4)
2323
; CHECK-NEXT: DW_AT_name {{.*}} "r"
2424
;
2525
; CHECK: DW_TAG_subprogram
2626
; CHECK: DW_AT_name {{.*}} "f"
2727
; CHECK: DW_TAG_variable
2828
; CHECK-NEXT: DW_AT_location {{.*}} ([[F:.*]]
29-
; CHECK-NEXT: [{{.*}}, {{.*}}): DW_OP_reg17 XMM0, DW_OP_piece 0x4, DW_OP_constu 0x0, DW_OP_stack_value, DW_OP_piece 0x4)
29+
; CHECK-NEXT: [{{.*}}, {{.*}}): DW_OP_reg17 XMM0, DW_OP_piece 0x4, DW_OP_lit0, DW_OP_stack_value, DW_OP_piece 0x4)
3030
; CHECK-NEXT: DW_AT_name {{.*}} "r"
3131
;
3232
; CHECK: .debug_loc contents:
3333
; CHECK: [[I]]:
34-
; CHECK-NEXT: [{{.*}}, {{.*}}): DW_OP_reg5 RDI, DW_OP_piece 0x4, DW_OP_constu 0x0, DW_OP_stack_value, DW_OP_piece 0x4
34+
; CHECK-NEXT: [{{.*}}, {{.*}}): DW_OP_reg5 RDI, DW_OP_piece 0x4, DW_OP_lit0, DW_OP_stack_value, DW_OP_piece 0x4
3535
; CHECK: [[F]]:
36-
; CHECK-NEXT: [{{.*}}, {{.*}}): DW_OP_reg17 XMM0, DW_OP_piece 0x4, DW_OP_constu 0x0, DW_OP_stack_value, DW_OP_piece 0x4
36+
; CHECK-NEXT: [{{.*}}, {{.*}}): DW_OP_reg17 XMM0, DW_OP_piece 0x4, DW_OP_lit0, DW_OP_stack_value, DW_OP_piece 0x4
3737

3838
source_filename = "stack-value-piece.c"
3939
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"

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