[PATCH] D68633: [utils] InlineFunction: fix for debug info affecting optimizations

[Chris Ye via Phabricator via llvm-commits]

yechunliang updated this revision to Diff 225811.
yechunliang added a comment.

changes:

1. using function name @foo and @bar instead of @f and @g for more complete match

2.cleanup test case with "-strip-dead-prototypes -strip-dead-debug-info"

Thank you @bjope for comments.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D68633/new/

https://reviews.llvm.org/D68633

Files:
  llvm/lib/Transforms/Utils/InlineFunction.cpp
  llvm/test/Transforms/Inline/inline-skip-use-empty-alloca.ll


Index: llvm/test/Transforms/Inline/inline-skip-use-empty-alloca.ll
===================================================================
--- /dev/null
+++ 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)
Index: llvm/lib/Transforms/Utils/InlineFunction.cpp
===================================================================
--- llvm/lib/Transforms/Utils/InlineFunction.cpp
+++ llvm/lib/Transforms/Utils/InlineFunction.cpp
@@ -1842,6 +1842,7 @@
       // Scan for the block of allocas that we can move over, and move them
       // all at once.
       while (isa<AllocaInst>(I) &&
+             !cast<AllocaInst>(I)->use_empty() &&
              allocaWouldBeStaticInEntry(cast<AllocaInst>(I))) {
         IFI.StaticAllocas.push_back(cast<AllocaInst>(I));
         ++I;


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