--- |
; RUN: llc -run-pass=machinelicm -o - %s | FileCheck %s
; Line numbers should not be retained when loop invariant instructions are hoisted.
; Doing so causes poor stepping bevavior.
;
; Created from:
; int x;
; void Process(const unsigned int *p)
; {
; while (1)
; x = *p++;
; }
;
; with clang -emit-llvm -S -O2 -g -o t.ll t.c
; llc -relocation-model=pic -stop-after=machine-combine -O2 t.ll -o t.mir
;
; We check that when the machine loop invariant pass hoists instructions
; out of a loop the debug information is not retained.
;
; CHECK-LABEL: bb.0.entry:
; CHECK: MOV64rm $rip, 1, $noreg, target-flags(x86-gotpcrel) @x, $noreg :: (load (s64) from got)
; CHECK-LABEL: bb.1.while.body:
;
; ModuleID = 'tx.ll'
source_filename = "t.c"
target triple = "x86_64-unknown-linux-gnu"
@x = common local_unnamed_addr global i32 0, align 4, !dbg !0
; Function Attrs: noreturn nounwind uwtable
define void @Process(ptr nocapture readonly %p) local_unnamed_addr !dbg !9 {
entry:
tail call void @llvm.dbg.value(metadata ptr %p, i64 0, metadata !16, metadata !17), !dbg !18
br label %while.body, !dbg !19
while.body: ; preds = %while.body, %entry
%p.addr.0 = phi ptr [ %p, %entry ], [ %incdec.ptr, %while.body ]
tail call void @llvm.dbg.value(metadata ptr %p.addr.0, i64 0, metadata !16, metadata !17), !dbg !18
%incdec.ptr = getelementptr inbounds i32, ptr %p.addr.0, i64 1, !dbg !20
tail call void @llvm.dbg.value(metadata ptr %incdec.ptr, i64 0, metadata !16, metadata !17), !dbg !18
%0 = load i32, ptr %p.addr.0, align 4, !dbg !21, !tbaa !22
store i32 %0, ptr @x, align 4, !dbg !26, !tbaa !22
br label %while.body, !dbg !27, !llvm.loop !29
}
; Function Attrs: nounwind readnone
declare void @llvm.dbg.value(metadata, i64, metadata, metadata)
!llvm.dbg.cu = !{!1}
!llvm.module.flags = !{!6, !7}
!llvm.ident = !{!8}
!0 = !DIGlobalVariableExpression(var: !DIGlobalVariable(name: "x", scope: !1, file: !2, line: 1, type: !5, isLocal: false, isDefinition: true), expr: !DIExpression())
!1 = distinct !DICompileUnit(language: DW_LANG_C99, file: !2, producer: "clang version 4.0.0 ", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !3, globals: !4)
!2 = !DIFile(filename: "t.c", directory: "/home/test")
!3 = !{}
!4 = !{!0}
!5 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
!6 = !{i32 2, !"Dwarf Version", i32 4}
!7 = !{i32 2, !"Debug Info Version", i32 3}
!8 = !{!"clang version 4.0.0 "}
!9 = distinct !DISubprogram(name: "Process", scope: !2, file: !2, line: 2, type: !10, isLocal: false, isDefinition: true, scopeLine: 3, flags: DIFlagPrototyped, isOptimized: true, unit: !1, retainedNodes: !15)
!10 = !DISubroutineType(types: !11)
!11 = !{null, !12}
!12 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !13, size: 64)
!13 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !14)
!14 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
!15 = !{!16}
!16 = !DILocalVariable(name: "p", arg: 1, scope: !9, file: !2, line: 2, type: !12)
!17 = !DIExpression()
!18 = !DILocation(line: 2, column: 34, scope: !9)
!19 = !DILocation(line: 4, column: 3, scope: !9)
!20 = !DILocation(line: 5, column: 11, scope: !9)
!21 = !DILocation(line: 5, column: 9, scope: !9)
!22 = !{!23, !23, i64 0}
!23 = !{!"int", !24, i64 0}
!24 = !{!"omnipotent char", !25, i64 0}
!25 = !{!"C++"}
!26 = !DILocation(line: 5, column: 7, scope: !9)
!27 = !DILocation(line: 4, column: 3, scope: !28)
!28 = !DILexicalBlockFile(scope: !9, file: !2, discriminator: 1)
!29 = distinct !{!29, !19, !20}
...
---
name: Process
tracksRegLiveness: true
registers:
- { id: 0, class: gr64 }
- { id: 1, class: gr64 }
- { id: 2, class: gr64 }
- { id: 3, class: gr32 }
- { id: 4, class: gr64 }
body: |
bb.0.entry:
successors: %bb.1.while.body(0x80000000)
liveins: $rdi
DBG_VALUE $rdi, _, !16, !17, debug-location !18
%2 = COPY $rdi
DBG_VALUE %2, _, !16, !17, debug-location !18
bb.1.while.body:
successors: %bb.1.while.body(0x80000000)
%0 = PHI %2, %bb.0.entry, %1, %bb.1.while.body
DBG_VALUE %0, _, !16, !17, debug-location !18
%1 = ADD64ri8 %0, 4, implicit-def dead $eflags, debug-location !20
DBG_VALUE %1, _, !16, !17, debug-location !18
%3 = MOV32rm %0, 1, _, 0, _, debug-location !21 :: (load (s32) from %ir.p.addr.0, !tbaa !22)
%4 = MOV64rm $rip, 1, _, target-flags(x86-gotpcrel) @x, _, debug-location !26 :: (load (s64) from got)
MOV32mr killed %4, 1, _, 0, _, killed %3, debug-location !26 :: (store (s32) into @x, !tbaa !22)
JMP_1 %bb.1.while.body, debug-location !27
...
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