Mircea TrofinandOwen Rodley
39dcb0ff91
This reverts #201194, thus relanding @orodley's PR #184065 (and #200323): > This allows us to keep GUIDs consistent across compilation phases which may change the name or linkage type. > See https://discourse.llvm.org/t/rfc-keep-globalvalue-guids-stable/84801 The CFI issues that triggered the original revert are fixed by #201370, together with the addressing of the TODOs in `LowerTypeTests.cpp` left in the latter. The [graphite diff](https://app.graphite.com/github/pr/llvm/llvm-project/201849/Reland-%23184065) between this change's V1 and V2 shows what's been added: - the `TODO`s from #201370 are done - in LowerTypeTests.cpp, passing `!guid` when creating a new declaration and when converting a definition to a declaration. - `llvm/test/Transforms/LowerTypeTests/export-icall.ll` tests also the above def->decl conversion - removed `test/Analysis/CtxProfAnalysis/flatten-prethinlink-requires-guid-metadata.ll` introduced in #194383 (this was between the revert and this PR), as now the general expectation is that GUID assignment happens appropriately and all passes use `getGUID`, so there's no reason for `CtxProfAnalysis` to do something different. Currently, we reassign GUIDs when CFI promotes internal linkage symbols, which is counter to the goal of the RFC. This is addressed in PR #203171. The reason for this split fix can be explained on `compiler-rt/test/cfi/icall/wrong-signature-mixed-lto.c`. Here, a module with the exact same source path is compiled twice, under different conditional compilation, to produce 2 objects. Each object defines an internal linkage symbol with the same name (this is `install_trap_loop_detection` from `compiler-rt/test/cfi/trap_loop_signal_handler.inc` which is `-include`\-d by both - see how `%clang_cfi` is defined). The ThinLTO GUID of this symbol will be the same. Its name won't be - because CFI promotes it and renames it using a hash that is based on the IR Module content (rather than the source path). During thinlink, `LTO::addThinLTO`will mark each of the 2 exported symbols as prevailing in their corresponding modules. But that is done by associating their GUID to the module. So whichever comes last wins. The other symbol will be marked available externally and its body DCEd later in backend. But each module will refer to its copy of `install_trap_loop_detection`, and so we end up with a linker error. As mentioned, the fix is in PR #203171, and this relanding PR just maintains the existing ThinLTO behavior by rewriting the GUIDs. Since we haven't yet leveraged the GUID mechanics for e.g. simplifying PGO, this aspect of this change is essentially NFC. Co-authored-by: Owen Rodley <orodley@google.com>
60 lines
3.2 KiB
LLVM
60 lines
3.2 KiB
LLVM
; Check the nonflattened part of the ctxsplit profile will be read in thinlto
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; postlink phase while flattened part of the ctxsplit profile will not be read.
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; RUN: opt < %s -passes='thinlto<O2>' -pgo-kind=pgo-sample-use-pipeline -use-profiled-call-graph=0 -profile-file=%S/Inputs/ctxsplit.extbinary.afdo -S | FileCheck %s --check-prefix=POSTLINK
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;
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; Check both the flattened and nonflattened parts of the ctxsplit profile will
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; be read in thinlto prelink phase.
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; RUN: opt < %s -passes='thinlto-pre-link<O2>' -pgo-kind=pgo-sample-use-pipeline -use-profiled-call-graph=0 -profile-file=%S/Inputs/ctxsplit.extbinary.afdo -S | FileCheck %s --check-prefix=PRELINK
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;
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; Check both the flattened and nonflattened parts of the ctxsplit profile will
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; be read in non-thinlto mode.
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; RUN: opt < %s -passes='default<O2>' -pgo-kind=pgo-sample-use-pipeline -use-profiled-call-graph=0 -profile-file=%S/Inputs/ctxsplit.extbinary.afdo -S | FileCheck %s --check-prefix=NOTHINLTO
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; POSTLINK: define dso_local noundef i32 @goo() {{.*}} !prof ![[ENTRY1:[0-9]+]] {
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; POSTLINK: define dso_local noundef i32 @foo() {{.*}} !prof ![[ENTRY2:[0-9]+]] {
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; POSTLINK: ![[ENTRY1]] = !{!"function_entry_count", i64 1001}
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; POSTLINK: ![[ENTRY2]] = !{!"function_entry_count", i64 -1}
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; PRELINK: define dso_local noundef i32 @goo() {{.*}} !prof ![[ENTRY1:[0-9]+]]
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; PRELINK: define dso_local noundef i32 @foo() {{.*}} !prof ![[ENTRY2:[0-9]+]]
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; PRELINK: ![[ENTRY1]] = !{!"function_entry_count", i64 1001}
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; PRELINK: ![[ENTRY2]] = !{!"function_entry_count", i64 3001}
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; NOTHINLTO: define dso_local noundef i32 @goo() {{.*}} !prof ![[ENTRY1:[0-9]+]]
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; NOTHINLTO: define dso_local noundef i32 @foo() {{.*}} !prof ![[ENTRY2:[0-9]+]]
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; NOTHINLTO: ![[ENTRY1]] = !{!"function_entry_count", i64 1001}
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; NOTHINLTO: ![[ENTRY2]] = !{!"function_entry_count", i64 3001}
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target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
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target triple = "x86_64-unknown-linux-gnu"
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; Function Attrs: norecurse nounwind readnone uwtable
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define dso_local i32 @goo() #0 !dbg !10 {
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entry:
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ret i32 -1, !dbg !11
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}
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; Function Attrs: norecurse nounwind readnone uwtable
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define dso_local i32 @foo() #0 !dbg !7 {
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entry:
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ret i32 -1, !dbg !9
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}
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attributes #0 = { "use-sample-profile" }
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!llvm.dbg.cu = !{!0}
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!llvm.module.flags = !{!3, !4, !5}
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!llvm.ident = !{!6}
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!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 8.0.0 (trunk 345241)", isOptimized: true, runtimeVersion: 0, emissionKind: LineTablesOnly, enums: !2, nameTableKind: None)
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!1 = !DIFile(filename: "a.c", directory: "")
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!2 = !{}
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!3 = !{i32 2, !"Dwarf Version", i32 4}
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!4 = !{i32 2, !"Debug Info Version", i32 3}
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!5 = !{i32 1, !"wchar_size", i32 4}
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!6 = !{!"clang version 8.0.0 (trunk 345241)"}
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!7 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 1, type: !8, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: true, unit: !0, retainedNodes: !2)
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!8 = !DISubroutineType(types: !2)
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!9 = !DILocation(line: 2, column: 3, scope: !7)
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!10 = distinct !DISubprogram(name: "goo", scope: !1, file: !1, line: 8, type: !8, isLocal: false, isDefinition: true, scopeLine: 8, isOptimized: true, unit: !0, retainedNodes: !2)
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!11 = !DILocation(line: 10, column: 3, scope: !10)
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