From 4bb535027e3c270e32631970e89afdfd2ded9fb1 Mon Sep 17 00:00:00 2001 From: Rafael Espindola Date: Thu, 28 Aug 2014 20:13:31 +0000 Subject: [PATCH] On MachO, don't put non-private constants in mergeable sections. On MachO, putting a symbol that doesn't start with a 'L' or 'l' in one of the __TEXT,__literal* sections prevents the linker from merging the context of the section. Since private GVs are the ones the get mangled to start with 'L' or 'l', we now only put those on the __TEXT,__literal* sections. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216682 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/TargetLoweringObjectFileImpl.cpp | 4 ++- test/CodeGen/X86/global-sections.ll | 29 ++++++++++++++++---- 2 files changed, 27 insertions(+), 6 deletions(-) diff --git a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp index 55e175680be..8820d10a0c6 100644 --- a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp +++ b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp @@ -626,7 +626,9 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, cast(GV)) < 32) return UStringSection; - if (Kind.isMergeableConst()) { + // With MachO only variables whose corresponding symbol starts with 'l' or + // 'L' can be merged, so we only try merging GVs with private linkage. + if (GV->hasPrivateLinkage() && Kind.isMergeableConst()) { if (Kind.isMergeableConst4()) return FourByteConstantSection; if (Kind.isMergeableConst8()) diff --git a/test/CodeGen/X86/global-sections.ll b/test/CodeGen/X86/global-sections.ll index c763f3947e5..fa1169d8a8e 100644 --- a/test/CodeGen/X86/global-sections.ll +++ b/test/CodeGen/X86/global-sections.ll @@ -53,21 +53,20 @@ define void @F1() { ; _Complex long long const G4 = 34; -@G4 = unnamed_addr constant {i64,i64} { i64 34, i64 0 } +@G4 = private unnamed_addr constant {i64,i64} { i64 34, i64 0 } ; DARWIN: .section __TEXT,__literal16,16byte_literals -; DARWIN: _G4: +; DARWIN: L_G4: ; DARWIN: .long 34 ; DARWIN-STATIC: .section __TEXT,__literal16,16byte_literals -; DARWIN-STATIC: _G4: +; DARWIN-STATIC: L_G4: ; DARWIN-STATIC: .long 34 ; DARWIN64: .section __TEXT,__literal16,16byte_literals -; DARWIN64: _G4: +; DARWIN64: L_G4: ; DARWIN64: .quad 34 - ; int G5 = 47; @G5 = global i32 47 @@ -194,3 +193,23 @@ define void @F1() { ; WIN32-SECTIONS: L_G14: ; WIN32-SECTIONS: .asciz "foo" +; cannot be merged on MachO, but can on other formats. +@G15 = unnamed_addr constant i64 0 + +; LINUX: .section .rodata.cst8,"aM",@progbits,8 +; LINUX: G15: + +; DARWIN: .section __TEXT,__const +; DARWIN: _G15: + +; DARWIN-STATIC: .section __TEXT,__const +; DARWIN-STATIC: _G15: + +; DARWIN64: .section __TEXT,__const +; DARWIN64: _G15: + +; LINUX-SECTIONS: .section .rodata.G15,"aM",@progbits,8 +; LINUX-SECTIONS: G15: + +; WIN32-SECTIONS: .section .rdata,"rd",one_only,_G15 +; WIN32-SECTIONS: _G15: -- 2.34.1