From 80cb2cecc65753aa1de09a09f3750408913f6450 Mon Sep 17 00:00:00 2001 From: Bjorn Pettersson Date: Mon, 28 Oct 2019 17:34:52 +0100 Subject: [PATCH] [utils] InlineFunction: fix for debug info affecting optimizations Summary: Debug info affects output from "opt -inline", InlineFunction could not handle the llvm.dbg.value when it exist between alloca instructions. Problem was that the first alloca in a sequence of allocas was handled differently from the subsequence alloca instructions. Now all static alloca instructions are treated the same (being removed if the have no uses). So it does not matter if there are dbg instructions (or any other instructions) in between. Fix the issue: https://bugs.llvm.org/show_bug.cgi?id=43291k Patch by: yechunliang (Chris Ye) Reviewers: bjope, jmorse, vsk, probinson, jdoerfert, mtrofin, aprantl, fhahn Reviewed By: bjope Subscribers: uabelho, ormris, aprantl, hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D68633 --- llvm/lib/Transforms/Utils/InlineFunction.cpp | 1 + .../Inline/inline-skip-use-empty-alloca.ll | 71 ++++++++++++++++++++++ 2 files changed, 72 insertions(+) create mode 100644 llvm/test/Transforms/Inline/inline-skip-use-empty-alloca.ll diff --git a/llvm/lib/Transforms/Utils/InlineFunction.cpp b/llvm/lib/Transforms/Utils/InlineFunction.cpp index 61da662..7e08da3 100644 --- a/llvm/lib/Transforms/Utils/InlineFunction.cpp +++ b/llvm/lib/Transforms/Utils/InlineFunction.cpp @@ -1842,6 +1842,7 @@ llvm::InlineResult llvm::InlineFunction(CallSite CS, InlineFunctionInfo &IFI, // Scan for the block of allocas that we can move over, and move them // all at once. while (isa(I) && + !cast(I)->use_empty() && allocaWouldBeStaticInEntry(cast(I))) { IFI.StaticAllocas.push_back(cast(I)); ++I; diff --git a/llvm/test/Transforms/Inline/inline-skip-use-empty-alloca.ll b/llvm/test/Transforms/Inline/inline-skip-use-empty-alloca.ll new file mode 100644 index 0000000..48545f1 --- /dev/null +++ b/llvm/test/Transforms/Inline/inline-skip-use-empty-alloca.ll @@ -0,0 +1,71 @@ +; RUN: opt < %s -S -inline | FileCheck %s +; RUN: opt < %s -S -strip-debug -inline | FileCheck %s + +; https://bugs.llvm.org/show_bug.cgi?id=43291 +; The purpose of this test is to check if there is use_empty in the inner loop when scanning +; blocks of allocas, if the alloca is use_empty, skip it when allocas inlining. + +define void @foo(i16 %k) !dbg !6 { + call void @llvm.dbg.value(metadata i16 %k, metadata !14, metadata !DIExpression()), !dbg !15 + %alloca_a = alloca i32 + call void @llvm.dbg.value(metadata i16 %k, metadata !14, metadata !DIExpression()), !dbg !15 + %alloca_b = alloca [3 x i32] + call void @llvm.dbg.value(metadata i16 %k, metadata !14, metadata !DIExpression()), !dbg !15 + %alloca_c = alloca i32 + call void @llvm.dbg.value(metadata i16 %k, metadata !14, metadata !DIExpression()), !dbg !15 + %alloca_a..1 = bitcast i32* %alloca_a to i8**, !dbg !16 + %alloca_c..1 = bitcast i32* %alloca_c to i8**, !dbg !16 + %_tmp23 = icmp ne i16 %k, 0 + br i1 %_tmp23, label %bb1, label %bb2 + +bb1: ; preds = %0 + %_tmp28 = getelementptr [3 x i32], [3 x i32]* %alloca_b, i16 0, i64 0 + store i32 0, i32* %_tmp28 + br label %bb2 + +bb2: ; preds = %bb1, %0 + ret void +} + +define i16 @bar() !dbg !17 { + ; CHECK-LABEL: bar + ; CHECK: %alloca_a.i = alloca i32 + ; CHECK-NOT: %alloca_b.i = alloca [3 x i32] + ; CHECK: %alloca_c.i = alloca i32 + call void @foo(i16 0), !dbg !20 + br label %bb1 + +bb1: ; preds = %0 + ret i16 0 +} + +; Function Attrs: nounwind readnone speculatable willreturn +declare void @llvm.dbg.value(metadata, metadata, metadata) #0 + +attributes #0 = { nounwind readnone speculatable willreturn } + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!3, !4} +!llvm.ident = !{!5} + +!0 = distinct !DICompileUnit(language: DW_LANG_C, file: !1, producer: "Foo", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !2, globals: !2) +!1 = !DIFile(filename: "foo2.c", directory: "/tmp") +!2 = !{} +!3 = !{i32 2, !"Dwarf Version", i32 4} +!4 = !{i32 2, !"Debug Info Version", i32 3} +!5 = !{!"Foo"} +!6 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 17, type: !7, scopeLine: 17, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2) +!7 = !DISubroutineType(types: !8) +!8 = !{!9, !13} +!9 = !DIDerivedType(tag: DW_TAG_typedef, name: "int64_t", file: !10, line: 76, baseType: !11) +!10 = !DIFile(filename: "stdint.h", directory: "/tmp") +!11 = !DIDerivedType(tag: DW_TAG_typedef, name: "__i64_t", file: !1, baseType: !12) +!12 = !DIBasicType(name: "signed long long", size: 64, encoding: DW_ATE_signed) +!13 = !DIBasicType(name: "int", size: 16, encoding: DW_ATE_signed) +!14 = !DILocalVariable(name: "k", arg: 1, scope: !6, file: !1, line: 17, type: !13) +!15 = !DILocation(line: 0, scope: !6) +!16 = !DILocation(line: 19, column: 3, scope: !6) +!17 = distinct !DISubprogram(name: "g", scope: !1, file: !1, line: 8, type: !18, scopeLine: 8, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2) +!18 = !DISubroutineType(types: !19) +!19 = !{!13} +!20 = !DILocation(line: 8, column: 7, scope: !17) -- 2.7.4