Files
clang-p2996/llvm/test/DebugInfo/Mips/dw_op_entry_value_64bit.ll
Jeremy Morse 1575583f2a [LiveDebugValues][InstrRef][2/2] Emit entry value variable locations
This patch adds support to the instruction-referencing LiveDebugValues
implementation for emitting entry values. The instruction referencing
implementations tracking by value rather than location means that we can
get around two of the issues with VarLocs. DBG_VALUE instructions that
re-assign the same value to a variable are no longer a problem, because we
can "see through" to the value being assigned. We also don't need to do
anything special during the dataflow stages: the "variable value problem"
doesn't need to know whether a value is available most of the time, and the
times it deoes need to know are always when entry values need to be
terminated.

The patch modifies the "TransferTracker" class, adding methods to identify
when a variable ias an entry value candidate, and when a machine value is
an entry value. recoverAsEntryValue tests these two things and emits an
entry-value expression if they're true. It's used when we clobber or
otherwise lose a value and can't find a replacement location for the value
it contained.

Differential Revision: https://reviews.llvm.org/D88406
2021-06-30 23:07:39 +01:00

80 lines
4.1 KiB
LLVM

;; Test mips64:
; RUN: llc -emit-call-site-info -stop-after=livedebugvalues -mtriple=mips64-linux-gnu -o - %s | FileCheck %s --check-prefix=CHECK64
; RUN: llc -force-instr-ref-livedebugvalues=1 -emit-call-site-info -stop-after=livedebugvalues -mtriple=mips64-linux-gnu -o - %s | FileCheck %s --check-prefix=CHECK64
;; Test mips64el:
; RUN: llc -emit-call-site-info -stop-after=livedebugvalues -mtriple=mips64el-linux-gnu -o - %s | FileCheck %s --check-prefix=CHECK64el
; RUN: llc -force-instr-ref-livedebugvalues=1 -emit-call-site-info -stop-after=livedebugvalues -mtriple=mips64el-linux-gnu -o - %s | FileCheck %s --check-prefix=CHECK64el
;; Built from source:
;; extern long fn1(long,long,long);
;; long fn2(long a, long b, long c) {
;; long local = fn1(a+b, c, b+10);
;; if (local > 10)
;; return local + 10;
;; return b;
;; }
;; Using command:
;; clang -g -O2 -target mips64-linux-gnu m.c -c -S -emit-llvm
;; Confirm that info from callSites attribute is used as entry_value in DIExpression.
;; Test mips64:
; CHECK64: $a0_64 = nsw DADDu $a1_64, killed renamable $a0_64,
; CHECK64-NEXT: DBG_VALUE $a0_64, $noreg, !15, !DIExpression(DW_OP_LLVM_entry_value, 1)
;; Test mips64el:
; CHECK64el: $a0_64 = nsw DADDu $a1_64, killed renamable $a0_64,
; CHECK64el-NEXT: DBG_VALUE $a0_64, $noreg, !15, !DIExpression(DW_OP_LLVM_entry_value, 1)
; ModuleID = 'm.c'
source_filename = "m.c"
target datalayout = "E-m:e-i8:8:32-i16:16:32-i64:64-n32:64-S128"
target triple = "mips64-unknown-linux-gnu"
; Function Attrs: nounwind
define i64 @fn2(i64 signext %a, i64 signext %b, i64 signext %c) local_unnamed_addr !dbg !13 {
entry:
call void @llvm.dbg.value(metadata i64 %a, metadata !15, metadata !DIExpression()), !dbg !19
call void @llvm.dbg.value(metadata i64 %b, metadata !16, metadata !DIExpression()), !dbg !19
call void @llvm.dbg.value(metadata i64 %c, metadata !17, metadata !DIExpression()), !dbg !19
%add = add nsw i64 %b, %a, !dbg !19
%add1 = add nsw i64 %b, 10, !dbg !19
%call = tail call i64 @fn1(i64 signext %add, i64 signext %c, i64 signext %add1), !dbg !19
call void @llvm.dbg.value(metadata i64 %call, metadata !18, metadata !DIExpression()), !dbg !19
%cmp = icmp sgt i64 %call, 10, !dbg !23
%add2 = add nsw i64 %call, 10, !dbg !19
%retval.0 = select i1 %cmp, i64 %add2, i64 %b, !dbg !19
ret i64 %retval.0, !dbg !19
}
declare !dbg !4 i64 @fn1(i64 signext, i64 signext, i64 signext) local_unnamed_addr
; Function Attrs: nounwind readnone speculatable willreturn
declare void @llvm.dbg.value(metadata, metadata, metadata)
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!8, !9, !10, !11}
!llvm.ident = !{!12}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 11.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !3, splitDebugInlining: false, nameTableKind: None)
!1 = !DIFile(filename: "m.c", directory: "/dir")
!2 = !{}
!3 = !{!4}
!4 = !DISubprogram(name: "fn1", scope: !1, file: !1, line: 1, type: !5, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized, retainedNodes: !2)
!5 = !DISubroutineType(types: !6)
!6 = !{!7, !7, !7, !7}
!7 = !DIBasicType(name: "long int", size: 64, encoding: DW_ATE_signed)
!8 = !{i32 7, !"Dwarf Version", i32 4}
!9 = !{i32 2, !"Debug Info Version", i32 3}
!10 = !{i32 1, !"wchar_size", i32 4}
!11 = !{i32 7, !"PIC Level", i32 1}
!12 = !{!"clang version 11.0.0"}
!13 = distinct !DISubprogram(name: "fn2", scope: !1, file: !1, line: 2, type: !5, scopeLine: 2, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !14)
!14 = !{!15, !16, !17, !18}
!15 = !DILocalVariable(name: "a", arg: 1, scope: !13, file: !1, line: 2, type: !7)
!16 = !DILocalVariable(name: "b", arg: 2, scope: !13, file: !1, line: 2, type: !7)
!17 = !DILocalVariable(name: "c", arg: 3, scope: !13, file: !1, line: 2, type: !7)
!18 = !DILocalVariable(name: "local", scope: !13, file: !1, line: 3, type: !7)
!19 = !DILocation(line: 0, scope: !13)
!23 = !DILocation(line: 4, column: 13, scope: !24)
!24 = distinct !DILexicalBlock(scope: !13, file: !1, line: 4, column: 7)