caio/clang-p2996
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
a0c9ec1f5e70e8f15da170667b2a8e63d024f3ab
clang-p2996/llvm/test/CodeGen/BPF/CORE/field-reloc-duplicate.ll
Yonghong Song edd71db38b BPF: avoid duplicated globals for CORE relocations 
This patch fixed two issues related with relocation globals.
In LLVM, if a global, e.g. with name "g", is created and
conflict with another global with the same name, LLVM will
rename the global, e.g., with a new name "g.2". Since
relocation global name has special meaning, we do not want
llvm to change it, so internally we have logic to check
whether duplication happens or not. If happens, just reuse
the previous global.

The first bug is related to non-btf-id relocation
(BPFAbstractMemberAccess.cpp). Commit 54d9f743c8
("BPF: move AbstractMemberAccess and PreserveDIType passes
to EP_EarlyAsPossible") changed ModulePass to FunctionPass,
i.e., handling each function at a time. But still just
one BPFAbstractMemberAccess object is created so module
level de-duplication still possible. Commit 40251fee00
("[BPF][NewPM] Make BPFTargetMachine properly adjust NPM optimizer
pipeline") made a change to create a BPFAbstractMemberAccess
object per function so module level de-duplication is not
possible any more without going through all module globals.
This patch simply changed the map which holds reloc globals
as class static, so it will be available to all
BPFAbstractMemberAccess objects for different functions.

The second bug is related to btf-id relocation
(BPFPreserveDIType.cpp). Before Commit 54d9f743c8, the pass
is a ModulePass, so we have a local variable, incremented for
each instance, and works fine. But after Commit 54d9f743c8,
the pass becomes a FunctionPass. Local variable won't work
properly since different functions will start with the same
initial value. Fix the issue by change the local count variable
as static, so it will be truely unique across the whole module
compilation.

Differential Revision: https://reviews.llvm.org/D88942
2020-10-06 22:37:49 -07:00

107 lines
5.7 KiB
LLVM
Raw Blame History

; RUN: opt -O2 -mtriple=bpf-pc-linux %s | llvm-dis > %t1
; RUN: llc -o - %t1 | FileCheck %s
; RUN: opt -passes='default<O2>' -mtriple=bpf-pc-linux %s | llvm-dis > %t1
; RUN: llc -o - %t1 | FileCheck %s
;
; Source:
; struct s1 { int a; int b; } __attribute__((preserve_access_index));
; int foo(struct s1 *arg) { return arg->a; }
; int bar(struct s1 *arg) { return arg->a; }
; Compilation flag:
; clang -target bpf -O2 -S -emit-llvm -g -Xclang -disable-llvm-passes test.c
%struct.s1 = type { i32, i32 }
; Function Attrs: nounwind
define dso_local i32 @foo(%struct.s1* %arg) #0 !dbg !7 {
entry:
%arg.addr = alloca %struct.s1*, align 8
store %struct.s1* %arg, %struct.s1** %arg.addr, align 8, !tbaa !18
call void @llvm.dbg.declare(metadata %struct.s1** %arg.addr, metadata !17, metadata !DIExpression()), !dbg !22
%0 = load %struct.s1*, %struct.s1** %arg.addr, align 8, !dbg !23, !tbaa !18
%1 = call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %0, i32 0, i32 0), !dbg !24, !llvm.preserve.access.index !12
%2 = load i32, i32* %1, align 4, !dbg !24, !tbaa !25
ret i32 %2, !dbg !28
}
; Function Attrs: nounwind readnone speculatable willreturn
declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
; Function Attrs: nounwind readnone
declare i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1*, i32 immarg, i32 immarg) #2
; Function Attrs: nounwind
define dso_local i32 @bar(%struct.s1* %arg) #0 !dbg !29 {
entry:
%arg.addr = alloca %struct.s1*, align 8
store %struct.s1* %arg, %struct.s1** %arg.addr, align 8, !tbaa !18
call void @llvm.dbg.declare(metadata %struct.s1** %arg.addr, metadata !31, metadata !DIExpression()), !dbg !32
%0 = load %struct.s1*, %struct.s1** %arg.addr, align 8, !dbg !33, !tbaa !18
%1 = call i32* @llvm.preserve.struct.access.index.p0i32.p0s_struct.s1s(%struct.s1* %0, i32 0, i32 0), !dbg !34, !llvm.preserve.access.index !12
%2 = load i32, i32* %1, align 4, !dbg !34, !tbaa !25
ret i32 %2, !dbg !35
}
; CHECK: .long 1 # BTF_KIND_STRUCT(id = 2)
; CHECK: .ascii "s1" # string offset=1
; CHECK: .ascii ".text" # string offset=20
; CHECK: .ascii "0:0" # string offset=26
; CHECK: .long 16 # FieldReloc
; CHECK-NEXT: .long 20 # Field reloc section string offset=20
; CHECK-NEXT: .long 2
; CHECK-NEXT: .long .Ltmp{{[0-9]+}}
; CHECK-NEXT: .long 2
; CHECK-NEXT: .long 26
; CHECK-NEXT: .long 0
; CHECK-NEXT: .long .Ltmp{{[0-9]+}}
; CHECK-NEXT: .long 2
; CHECK-NEXT: .long 26
; CHECK-NEXT: .long 0
attributes #0 = { nounwind "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { nounwind readnone speculatable willreturn }
attributes #2 = { nounwind readnone }
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3, !4, !5}
!llvm.ident = !{!6}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 12.0.0 (https://github.com/llvm/llvm-project.git 2f40e20613758b3e11a15494c09f4b6973673d6b)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
!1 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/work/tests/core")
!2 = !{}
!3 = !{i32 7, !"Dwarf Version", i32 4}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!5 = !{i32 1, !"wchar_size", i32 4}
!6 = !{!"clang version 12.0.0 (https://github.com/llvm/llvm-project.git 2f40e20613758b3e11a15494c09f4b6973673d6b)"}
!7 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 2, type: !8, scopeLine: 2, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !16)
!8 = !DISubroutineType(types: !9)
!9 = !{!10, !11}
!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
!11 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !12, size: 64)
!12 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "s1", file: !1, line: 1, size: 64, elements: !13)
!13 = !{!14, !15}
!14 = !DIDerivedType(tag: DW_TAG_member, name: "a", scope: !12, file: !1, line: 1, baseType: !10, size: 32)
!15 = !DIDerivedType(tag: DW_TAG_member, name: "b", scope: !12, file: !1, line: 1, baseType: !10, size: 32, offset: 32)
!16 = !{!17}
!17 = !DILocalVariable(name: "arg", arg: 1, scope: !7, file: !1, line: 2, type: !11)
!18 = !{!19, !19, i64 0}
!19 = !{!"any pointer", !20, i64 0}
!20 = !{!"omnipotent char", !21, i64 0}
!21 = !{!"Simple C/C++ TBAA"}
!22 = !DILocation(line: 2, column: 20, scope: !7)
!23 = !DILocation(line: 2, column: 34, scope: !7)
!24 = !DILocation(line: 2, column: 39, scope: !7)
!25 = !{!26, !27, i64 0}
!26 = !{!"s1", !27, i64 0, !27, i64 4}
!27 = !{!"int", !20, i64 0}
!28 = !DILocation(line: 2, column: 27, scope: !7)
!29 = distinct !DISubprogram(name: "bar", scope: !1, file: !1, line: 3, type: !8, scopeLine: 3, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !30)
!30 = !{!31}
!31 = !DILocalVariable(name: "arg", arg: 1, scope: !29, file: !1, line: 3, type: !11)
!32 = !DILocation(line: 3, column: 20, scope: !29)
!33 = !DILocation(line: 3, column: 34, scope: !29)
!34 = !DILocation(line: 3, column: 39, scope: !29)
!35 = !DILocation(line: 3, column: 27, scope: !29)
Reference in New Issue View Git Blame Copy Permalink