From 9f953cdd7c3f0e77d1a53948d0128e37ab5ea994 Mon Sep 17 00:00:00 2001 From: Bjorn Pettersson Date: Wed, 9 May 2018 06:52:12 +0000 Subject: [PATCH] [MergedLoadStoreMotion] Fix a debug invariant bug in mergeStores Summary: MergedLoadStoreMotion::mergeStores is using some heuristics to limit the amount of stores that it tries to sink (see MagicCompileTimeControl in MergedLoadStoreMotion.cpp). The heuristic involves counting the number of instructions in one of the basic blocks that is part of the transformation. We now ignore dbg intrinsics when counting instruction for the MagicCompileTimeControl heuristic. This to make sure that the amount of stores that are sunk doesn't depend on the amount of debug information (if -g is used or not). Reviewers: Gerolf, davide, majnemer Reviewed By: davide Subscribers: dberlin, bjope, aprantl, JDevlieghere, llvm-commits Differential Revision: https://reviews.llvm.org/D46600 llvm-svn: 331852 --- .../Transforms/Scalar/MergedLoadStoreMotion.cpp | 3 +- .../Transforms/InstMerge/st_sink_debuginvariant.ll | 156 +++++++++++++++++++++ 2 files changed, 158 insertions(+), 1 deletion(-) create mode 100644 llvm/test/Transforms/InstMerge/st_sink_debuginvariant.ll diff --git a/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp b/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp index cbed9a9..35e341f 100644 --- a/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp +++ b/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp @@ -285,7 +285,8 @@ bool MergedLoadStoreMotion::mergeStores(BasicBlock *T) { return false; // No. More than 2 predecessors. // #Instructions in Succ1 for Compile Time Control - int Size1 = Pred1->size(); + int Size1 = std::distance(Pred1->instructionsWithoutDebug().begin(), + Pred1->instructionsWithoutDebug().end()); int NStores = 0; for (BasicBlock::reverse_iterator RBI = Pred0->rbegin(), RBE = Pred0->rend(); diff --git a/llvm/test/Transforms/InstMerge/st_sink_debuginvariant.ll b/llvm/test/Transforms/InstMerge/st_sink_debuginvariant.ll new file mode 100644 index 0000000..4a2d804 --- /dev/null +++ b/llvm/test/Transforms/InstMerge/st_sink_debuginvariant.ll @@ -0,0 +1,156 @@ +; RUN: opt < %s -S -mldst-motion -o - | FileCheck %s +; RUN: opt < %s -S -strip-debug -mldst-motion -o - | FileCheck %s + +; Verify that the amount of stores that are sunk is invariant regarding debug +; info. This used to fail due to including dbg.value instructions when +; calculating the size of a basic block for the "MagicCompileTimeControl" +; check in MergedLoadStoreMotion::mergeStores. + +; CHECK-LABEL: return: +; CHECK-NEXT: %.sink = phi i16 [ 5, %if.end ], [ 6, %if.then ] +; CHECK-NEXT: %0 = getelementptr inbounds %struct.S0, %struct.S0* %agg.result, i16 0, i32 0 +; CHECK-NEXT: store i16 %.sink, i16* %0 +; CHECK-NEXT: %1 = getelementptr inbounds %struct.S0, %struct.S0* %agg.result, i16 0, i32 1 +; CHECK-NEXT: store i16 0, i16* %1 +; CHECK-NEXT: ret void + +%struct.S0 = type { i16, i16 } + +@g_173 = dso_local local_unnamed_addr global i16 0, !dbg !0 + +; Function Attrs: noinline norecurse nounwind +define dso_local void @func_34(%struct.S0* noalias sret %agg.result) local_unnamed_addr #0 !dbg !11 { +entry: + br i1 undef, label %if.end, label %if.then, !dbg !18 + +if.then: ; preds = %entry + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + call void @llvm.dbg.value(metadata i16 5, metadata !19, metadata !DIExpression()), !dbg !22 + %l_303.sroa.0.0..sroa_idx = getelementptr inbounds %struct.S0, %struct.S0* %agg.result, i16 0, i32 0, !dbg !23 + store i16 6, i16* %l_303.sroa.0.0..sroa_idx, !dbg !23 + %l_303.sroa.2.0..sroa_idx1 = getelementptr inbounds %struct.S0, %struct.S0* %agg.result, i16 0, i32 1, !dbg !23 + store i16 0, i16* %l_303.sroa.2.0..sroa_idx1, !dbg !23 + br label %return, !dbg !24 + +if.end: ; preds = %entry + %f037 = getelementptr inbounds %struct.S0, %struct.S0* %agg.result, i16 0, i32 0, !dbg !25 + store i16 5, i16* %f037, !dbg !25 + %f138 = getelementptr inbounds %struct.S0, %struct.S0* %agg.result, i16 0, i32 1, !dbg !25 + store i16 0, i16* %f138, !dbg !25 + store i16 0, i16* @g_173, !dbg !27 + br label %return, !dbg !28 + +return: ; preds = %if.end, %if.then + ret void, !dbg !29 +} + +; Function Attrs: nounwind readnone speculatable +declare void @llvm.dbg.value(metadata, metadata, metadata) #1 + +attributes #0 = { noinline norecurse nounwind } +attributes #1 = { nounwind readnone speculatable } + +!llvm.dbg.cu = !{!2} +!llvm.module.flags = !{!7, !8, !9} +!llvm.ident = !{!10} + +!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression()) +!1 = distinct !DIGlobalVariable(name: "g_173", scope: !2, file: !3, line: 7, type: !6, isLocal: false, isDefinition: true) +!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 7.0.0 (x)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5) +!3 = !DIFile(filename: "csmith11794002068761.c", directory: "") +!4 = !{} +!5 = !{!0} +!6 = !DIBasicType(name: "int", size: 16, encoding: DW_ATE_signed) +!7 = !{i32 2, !"Dwarf Version", i32 4} +!8 = !{i32 2, !"Debug Info Version", i32 3} +!9 = !{i32 1, !"wchar_size", i32 1} +!10 = !{!"clang version 7.0.0 (x)"} +!11 = distinct !DISubprogram(name: "func_34", scope: !3, file: !3, line: 16, type: !12, isLocal: false, isDefinition: true, scopeLine: 16, isOptimized: false, unit: !2, retainedNodes: !4) +!12 = !DISubroutineType(types: !13) +!13 = !{!14} +!14 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "S0", file: !3, line: 2, size: 32, elements: !15) +!15 = !{!16, !17} +!16 = !DIDerivedType(tag: DW_TAG_member, name: "f0", scope: !14, file: !3, line: 3, baseType: !6, size: 16) +!17 = !DIDerivedType(tag: DW_TAG_member, name: "f1", scope: !14, file: !3, line: 4, baseType: !6, size: 16, offset: 16) +!18 = !DILocation(line: 18, column: 7, scope: !11) +!19 = !DILocalVariable(name: "left", scope: !20, file: !3, line: 23, type: !6) +!20 = distinct !DILexicalBlock(scope: !21, file: !3, line: 18, column: 14) +!21 = distinct !DILexicalBlock(scope: !11, file: !3, line: 18, column: 7) +!22 = !DILocation(line: 23, column: 9, scope: !20) +!23 = !DILocation(line: 26, column: 12, scope: !20) +!24 = !DILocation(line: 26, column: 5, scope: !20) +!25 = !DILocation(line: 29, column: 23, scope: !26) +!26 = distinct !DILexicalBlock(scope: !11, file: !3, line: 28, column: 3) +!27 = !DILocation(line: 30, column: 11, scope: !26) +!28 = !DILocation(line: 31, column: 5, scope: !26) +!29 = !DILocation(line: 33, column: 1, scope: !11) -- 2.7.4