a701b7e368
Before elimination of mostly empty block it makes sense to remove dead PHI nodes. It open more opportunity for elimination plus eliminates dead code itself. It appeared that change results in failing many unit tests and some of them I've updated and for another one I disable this optimization. The pattern I observed in the tests is that there is a infinite loop without side effects. As a result after elimination of dead phi node all other related instruction are also removed and tests stops to check what it is expected. Reviewed By: efriedma Differential Revision: https://reviews.llvm.org/D158503
92 lines
3.5 KiB
LLVM
92 lines
3.5 KiB
LLVM
; RUN: opt -codegenprepare -S < %s | FileCheck %s
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; RUN: opt -strip-debug -codegenprepare -S < %s | FileCheck %s
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; REQUIRES: x86-registered-target
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; In its current state, CodeGenPrepare should not optimize empty blocks after a switch
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; (See CodeGenPrepare::isMergingEmptyBlockProfitable)
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; This should also be the case when they contain debug information. (sw.bb block)
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; Check this by verifying that the switch labels remain the same
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; CHECK: while.cond:
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; CHECK-NEXT: switch i32 undef, label %sw.default [
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; CHECK-NEXT: i32 45, label %sw.bb
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; CHECK-NEXT: i32 104, label %while.cond.lbl_crit_edge
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; CHECK-NEXT: i32 122, label %while.cond.lbl_crit_edge
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; CHECK-NEXT: i32 115, label %while.cond134.preheader
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; CHECK-NEXT: i32 100, label %sw.bb29
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; CHECK-NEXT: i32 105, label %sw.bb29
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; CHECK-NEXT: ]
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; ModuleID = 'bugpoint-reduced-instructions.bc'
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source_filename = "foobar.c"
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target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
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target triple = "x86_64-unknown-linux-gnu"
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; Function Attrs: nounwind readnone speculatable
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declare void @llvm.dbg.declare(metadata, metadata, metadata) #0
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; Function Attrs: nounwind readnone speculatable
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declare void @llvm.dbg.value(metadata, metadata, metadata) #0
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; Function Attrs: noinline nounwind uwtable
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define dso_local void @foobar(ptr nocapture %arg0) local_unnamed_addr #0 {
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entry:
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br label %while.cond
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while.cond: ; preds = %entry
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switch i32 undef, label %sw.default [
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i32 45, label %sw.bb
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i32 104, label %while.cond.lbl_crit_edge
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i32 122, label %while.cond.lbl_crit_edge
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i32 115, label %while.cond134.preheader
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i32 100, label %sw.bb29
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i32 105, label %sw.bb29
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]
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while.cond.lbl_crit_edge: ; preds = %while.cond, %while.cond
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br label %lbl
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while.cond134.preheader: ; preds = %while.cond
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unreachable
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sw.bb: ; preds = %while.cond
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call void @llvm.dbg.value(metadata i32 3, metadata !11, metadata !DIExpression()), !dbg !15
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br label %lbl
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sw.bb29: ; preds = %while.cond, %while.cond
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unreachable
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sw.default: ; preds = %while.cond
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unreachable
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lbl: ; preds = %sw.bb, %while.cond.lbl_crit_edge
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%var03.1 = phi i32 [ 0, %while.cond.lbl_crit_edge ], [ 3, %sw.bb ]
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br label %phi_use
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phi_use:
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store i32 %var03.1, ptr %arg0
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unreachable
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}
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attributes #0 = { nounwind readnone speculatable }
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!llvm.dbg.cu = !{!0}
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!llvm.module.flags = !{!9, !10}
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!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version XXX ", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !3, globals: !2)
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!1 = !DIFile(filename: "foobar.c", directory: "./")
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!2 = !{}
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!3 = !{!4, !5}
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!4 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
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!5 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !6, size: 64)
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!6 = !DISubroutineType(types: !7)
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!7 = !{!4, !4, !8}
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!8 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 64)
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!9 = !{i32 2, !"Debug Info Version", i32 3}
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!10 = !{i32 1, !"wchar_size", i32 4}
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!11 = !DILocalVariable(name: "var03", scope: !12, file: !1, line: 3, type: !4)
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!12 = distinct !DISubprogram(name: "foobar", scope: !1, file: !1, line: 2, type: !13, isLocal: false, isDefinition: true, scopeLine: 4, flags: DIFlagPrototyped, isOptimized: false, unit: !0, retainedNodes: !2)
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!13 = !DISubroutineType(types: !14)
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!14 = !{null, !5, !8}
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!15 = !DILocation(line: 4, column: 16, scope: !12)
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