620a529760
Enabling assignment tracking without this patch, a significant amount of additional compiler run time comes from the RemoveRedundantDbgInstrs call in InstCombine. This patch reduces compiler run time by choosing better places to call RemoveRedundantDbgInstrs. In non-assignment-tracking builds, RemoveRedundantDbgInstrs is called by InstCombine if LowerDbgDeclare makes a change (i.e. it is _sometimes_ called). In assignment tracking builds LowerDbgDeclare doesn't do anything. We still need to clean up redundant intrinsics to avoid a large performance hit due to the number of instructions, so the current approach is to have InstCombine _always_ call RemoveRedundantDbgInstrs. Instrumenting the compiler to run RemoveRedundantDbgInstrs after every pass and dump the numbers and building CTMark/tramp3d-v4 indicates that SROA and LoopVectorize give us a bigger bang (number removed) for buck (times pass is run). The compile time tracker reports that this patch reduces the number of instructions retired building CTMark projects by an average of 1.1%. Reviewed By: scott.linder Differential Revision: https://reviews.llvm.org/D144483
62 lines
2.9 KiB
LLVM
62 lines
2.9 KiB
LLVM
; RUN: opt %s -passes=loop-vectorize -force-vector-width=2 -force-vector-interleave=2 -S -o - \
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; RUN: | FileCheck %s --implicit-check-not="call void @llvm.dbg"
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;; Check that loop-vectorize removes redundant debug intrinsics after it makes
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;; a change. This has a significant positive impact on peak memory and compiler
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;; run time.
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;; Check there is only one dbg.assign.
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; CHECK: call void @llvm.dbg.assign
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;; Check that the loop was actually modified.
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; CHECK: extractelement
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define void @test1(ptr noalias nocapture %a, ptr noalias nocapture readonly %b) {
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entry:
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call void @llvm.dbg.assign(metadata ptr %a, metadata !11, metadata !DIExpression(), metadata !16, metadata ptr undef, metadata !DIExpression()), !dbg !28
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call void @llvm.dbg.assign(metadata ptr %a, metadata !11, metadata !DIExpression(), metadata !16, metadata ptr undef, metadata !DIExpression()), !dbg !28
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br label %for.body
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for.body: ; preds = %for.body, %entry
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%indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
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%arrayidx = getelementptr inbounds float, ptr %b, i64 %indvars.iv
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%0 = load float, ptr %arrayidx, align 4
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%cmp1 = fcmp ogt float %0, 1.000000e+02
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tail call void @llvm.assume(i1 %cmp1)
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%add = fadd float %0, 1.000000e+00
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%arrayidx5 = getelementptr inbounds float, ptr %a, i64 %indvars.iv
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store float %add, ptr %arrayidx5, align 4
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%indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
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%exitcond = icmp eq i64 %indvars.iv, 1599
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br i1 %exitcond, label %for.end, label %for.body
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for.end: ; preds = %for.body
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ret void
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}
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declare void @llvm.assume(i1) #0
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declare void @llvm.dbg.assign(metadata, metadata, metadata, metadata, metadata, metadata)
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!llvm.dbg.cu = !{!0}
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!llvm.module.flags = !{!2, !3, !4, !5, !1000}
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!llvm.ident = !{!6}
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!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 14.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None)
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!1 = !DIFile(filename: "test.cpp", directory: "/")
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!2 = !{i32 7, !"Dwarf Version", i32 5}
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!3 = !{i32 2, !"Debug Info Version", i32 3}
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!4 = !{i32 1, !"wchar_size", i32 4}
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!5 = !{i32 7, !"uwtable", i32 1}
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!6 = !{!"clang version 14.0.0)"}
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!7 = distinct !DISubprogram(name: "fun", linkageName: "_Z3funv", scope: !1, file: !1, line: 2, type: !8, scopeLine: 2, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !10)
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!8 = !DISubroutineType(types: !9)
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!9 = !{null}
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!10 = !{!11}
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!11 = !DILocalVariable(name: "Counter", scope: !7, file: !1, line: 3, type: !12)
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!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
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!16 = distinct !DIAssignID()
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!19 = distinct !DILexicalBlock(scope: !7, file: !1, line: 4, column: 3)
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!28 = !DILocation(line: 6, column: 1, scope: !7)
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!1000 = !{i32 7, !"debug-info-assignment-tracking", i1 true}
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