987d331fab
Summary: The motivating use case is eliminating duplicate profile data registered for the same inline function in two object files. Before this change, users would observe multiple symbol definition errors with VC link, but links with LLD would succeed. Users (Mozilla) have reported that PGO works well with clang-cl and LLD, but when using LLD without this static registration, we would get into a "relocation against a discarded section" situation. I'm not sure what happens in that situation, but I suspect that duplicate, unused profile information was retained. If so, this change will reduce the size of such binaries with LLD. Now, Windows uses static registration and is in line with all the other platforms. Reviewers: davidxl, wmi, inglorion, void, calixte Subscribers: mgorny, krytarowski, eraman, fedor.sergeev, hiraditya, #sanitizers, dmajor, llvm-commits Tags: #sanitizers, #llvm Differential Revision: https://reviews.llvm.org/D57929 llvm-svn: 353547
39 lines
2.2 KiB
LLVM
39 lines
2.2 KiB
LLVM
; RUN: opt < %s -mtriple=x86_64-unknown-linux -instrprof -S | FileCheck %s --check-prefixes=ELF
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; RUN: opt < %s -mtriple=x86_64-pc-win32-coff -instrprof -S | FileCheck %s --check-prefixes=COFF
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; RUN: opt < %s -mtriple=x86_64-unknown-linux -passes=instrprof -S | FileCheck %s --check-prefixes=ELF
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; RUN: opt < %s -mtriple=x86_64-pc-win32-coff -passes=instrprof -S | FileCheck %s --check-prefixes=COFF
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; There are two main cases where comdats are necessary:
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; 1. standard inline functions (weak_odr / linkonce_odr)
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; 2. available externally functions (C99 inline / extern template / dllimport)
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; Check that we do the right thing for the two object formats with comdats, ELF
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; and COFF.
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declare void @llvm.instrprof.increment(i8*, i64, i32, i32)
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$foo_inline = comdat any
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@__profn_foo_inline = linkonce_odr hidden constant [10 x i8] c"foo_inline"
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; ELF: @__profc_foo_inline = linkonce_odr hidden global{{.*}}, section "__llvm_prf_cnts", comdat($__profv_foo_inline), align 8
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; ELF: @__profd_foo_inline = linkonce_odr hidden global{{.*}}, section "__llvm_prf_data", comdat($__profv_foo_inline), align 8
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; COFF: @__profc_foo_inline = internal global{{.*}}, section ".lprfc$M", comdat($foo_inline), align 8
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; COFF: @__profd_foo_inline = internal global{{.*}}, section ".lprfd$M", comdat($foo_inline), align 8
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define weak_odr void @foo_inline() comdat {
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call void @llvm.instrprof.increment(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @__profn_foo_inline, i32 0, i32 0), i64 0, i32 1, i32 0)
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ret void
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}
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$foo_extern = comdat any
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@__profn_foo_extern = linkonce_odr hidden constant [10 x i8] c"foo_extern"
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; ELF: @__profc_foo_extern = linkonce_odr hidden global{{.*}}, section "__llvm_prf_cnts", comdat($__profv_foo_extern)
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; ELF: @__profd_foo_extern = linkonce_odr hidden global{{.*}}, section "__llvm_prf_data", comdat($__profv_foo_extern)
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; COFF: @__profc_foo_extern = linkonce_odr dso_local global{{.*}}, section ".lprfc$M", comdat, align 8
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; COFF: @__profd_foo_extern = internal global{{.*}}, section ".lprfd$M", comdat($__profc_foo_extern), align 8
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define available_externally void @foo_extern() {
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call void @llvm.instrprof.increment(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @__profn_foo_extern, i32 0, i32 0), i64 0, i32 1, i32 0)
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ret void
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}
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