56f7de5baa
InstCombine removes pairs of start+end intrinsics that don't have anything in between them. Currently this is done by starting at the start intrinsic and scanning forwards. This patch changes it to start at the end intrinsic and scan backwards. The motivation here is as follows: When we process the start intrinsic, we have not yet looked at the following instructions, which may still get folded/removed. If they do, we will only be able to remove the start/end pair on the next iteration. When we process the end intrinsic, all the instructions before it have already been visited, and we don't run into this problem. Differential Revision: https://reviews.llvm.org/D75011
93 lines
4.1 KiB
LLVM
93 lines
4.1 KiB
LLVM
; RUN: opt < %s -instcombine -instcombine-infinite-loop-threshold=2 -S | FileCheck %s
|
|
|
|
declare void @llvm.dbg.declare(metadata, metadata, metadata)
|
|
declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture)
|
|
declare void @llvm.lifetime.end.p0i8(i64, i8* nocapture)
|
|
declare void @foo(i8* nocapture, i8* nocapture)
|
|
|
|
define void @bar(i1 %flag) !dbg !4 {
|
|
entry:
|
|
; CHECK-LABEL: @bar(
|
|
; CHECK: %[[T:[^ ]+]] = getelementptr inbounds [1 x i8], [1 x i8]* %text
|
|
; CHECK: %[[B:[^ ]+]] = getelementptr inbounds [1 x i8], [1 x i8]* %buff
|
|
; CHECK: if:
|
|
; CHECK-NEXT: br label %bb2
|
|
; CHECK: bb2:
|
|
; CHECK-NEXT: br label %bb3
|
|
; CHECK: bb3:
|
|
; CHECK-NEXT: call void @llvm.dbg.declare
|
|
; CHECK-NEXT: br label %fin
|
|
; CHECK: call void @llvm.lifetime.start.p0i8(i64 1, i8* nonnull %[[T]])
|
|
; CHECK-NEXT: call void @llvm.lifetime.start.p0i8(i64 1, i8* nonnull %[[B]])
|
|
; CHECK-NEXT: call void @foo(i8* nonnull %[[B]], i8* nonnull %[[T]])
|
|
; CHECK-NEXT: call void @llvm.lifetime.end.p0i8(i64 1, i8* nonnull %[[B]])
|
|
; CHECK-NEXT: call void @llvm.lifetime.end.p0i8(i64 1, i8* nonnull %[[T]])
|
|
%text = alloca [1 x i8], align 1
|
|
%buff = alloca [1 x i8], align 1
|
|
%0 = getelementptr inbounds [1 x i8], [1 x i8]* %text, i64 0, i64 0
|
|
%1 = getelementptr inbounds [1 x i8], [1 x i8]* %buff, i64 0, i64 0
|
|
br i1 %flag, label %if, label %else
|
|
|
|
if:
|
|
call void @llvm.lifetime.start.p0i8(i64 1, i8* %0)
|
|
call void @llvm.lifetime.start.p0i8(i64 1, i8* %1)
|
|
call void @llvm.lifetime.end.p0i8(i64 1, i8* %1)
|
|
call void @llvm.lifetime.end.p0i8(i64 1, i8* %0)
|
|
br label %bb2
|
|
|
|
bb2:
|
|
call void @llvm.lifetime.start.p0i8(i64 1, i8* %0)
|
|
call void @llvm.lifetime.start.p0i8(i64 1, i8* %1)
|
|
call void @llvm.lifetime.end.p0i8(i64 1, i8* %0)
|
|
call void @llvm.lifetime.end.p0i8(i64 1, i8* %1)
|
|
br label %bb3
|
|
|
|
bb3:
|
|
call void @llvm.lifetime.start.p0i8(i64 1, i8* %0)
|
|
call void @llvm.dbg.declare(metadata [1 x i8]* %text, metadata !14, metadata !25), !dbg !26
|
|
call void @llvm.lifetime.end.p0i8(i64 1, i8* %0)
|
|
br label %fin
|
|
|
|
else:
|
|
call void @llvm.lifetime.start.p0i8(i64 1, i8* %0)
|
|
call void @llvm.lifetime.start.p0i8(i64 1, i8* %1)
|
|
call void @foo(i8* %1, i8* %0)
|
|
call void @llvm.lifetime.end.p0i8(i64 1, i8* %1)
|
|
call void @llvm.lifetime.end.p0i8(i64 1, i8* %0)
|
|
br label %fin
|
|
|
|
fin:
|
|
ret void
|
|
}
|
|
|
|
!llvm.dbg.cu = !{!0}
|
|
!llvm.module.flags = !{!22, !23}
|
|
!llvm.ident = !{!24}
|
|
|
|
!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 3.8.0 (trunk 248826) (llvm/trunk 248827)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
|
|
!1 = !DIFile(filename: "test.cpp", directory: "/home/user")
|
|
!2 = !{}
|
|
!4 = distinct !DISubprogram(name: "bar", linkageName: "bar", scope: !1, file: !1, line: 2, type: !5, isLocal: false, isDefinition: true, scopeLine: 2, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !8)
|
|
!5 = !DISubroutineType(types: !6)
|
|
!6 = !{null, !7}
|
|
!7 = !DIBasicType(name: "bool", size: 8, align: 8, encoding: DW_ATE_boolean)
|
|
!8 = !{!9, !11, !12, !14, !21}
|
|
!9 = !DILocalVariable(name: "Size", arg: 1, scope: !4, file: !1, line: 2, type: !10)
|
|
!10 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
|
|
!11 = !DILocalVariable(name: "flag", arg: 2, scope: !4, file: !1, line: 2, type: !7)
|
|
!12 = !DILocalVariable(name: "i", scope: !13, file: !1, line: 3, type: !10)
|
|
!13 = distinct !DILexicalBlock(scope: !4, file: !1, line: 3, column: 3)
|
|
!14 = !DILocalVariable(name: "text", scope: !15, file: !1, line: 4, type: !17)
|
|
!15 = distinct !DILexicalBlock(scope: !16, file: !1, line: 3, column: 30)
|
|
!16 = distinct !DILexicalBlock(scope: !13, file: !1, line: 3, column: 3)
|
|
!17 = !DICompositeType(tag: DW_TAG_array_type, baseType: !18, size: 8, align: 8, elements: !19)
|
|
!18 = !DIBasicType(name: "char", size: 8, align: 8, encoding: DW_ATE_signed_char)
|
|
!19 = !{!20}
|
|
!20 = !DISubrange(count: 1)
|
|
!21 = !DILocalVariable(name: "buff", scope: !15, file: !1, line: 5, type: !17)
|
|
!22 = !{i32 2, !"Dwarf Version", i32 4}
|
|
!23 = !{i32 2, !"Debug Info Version", i32 3}
|
|
!24 = !{!"clang version 3.8.0 (trunk 248826) (llvm/trunk 248827)"}
|
|
!25 = !DIExpression()
|
|
!26 = !DILocation(line: 4, column: 10, scope: !15)
|