From b266ccd0f41b3ac9d9ad733e73204d9177c12e9f Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Thu, 18 Jan 2007 01:15:58 +0000 Subject: [PATCH] Modify emission of jump tables on darwin to emit an extra "l" label that delimits the boundaries of jump tables. This lets the linker's dead code stripping optimization do a better job. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@33315 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/PowerPC/PPCTargetAsmInfo.cpp | 7 +++++++ lib/Target/X86/X86TargetAsmInfo.cpp | 7 +++++++ 2 files changed, 14 insertions(+) diff --git a/lib/Target/PowerPC/PPCTargetAsmInfo.cpp b/lib/Target/PowerPC/PPCTargetAsmInfo.cpp index b9f5849bdf6..b54c9e9eb65 100644 --- a/lib/Target/PowerPC/PPCTargetAsmInfo.cpp +++ b/lib/Target/PowerPC/PPCTargetAsmInfo.cpp @@ -57,6 +57,13 @@ DarwinTargetAsmInfo::DarwinTargetAsmInfo(const PPCTargetMachine &TM) UsedDirective = "\t.no_dead_strip\t"; WeakRefDirective = "\t.weak_reference\t"; HiddenDirective = "\t.private_extern\t"; + + // In non-PIC modes, emit a special label before jump tables so that the + // linker can perform more accurate dead code stripping. + if (TM.getRelocationModel() != Reloc::PIC_) { + // Emit a local label that is preserved until the linker runs. + JumpTableSpecialLabelPrefix = "l"; + } } LinuxTargetAsmInfo::LinuxTargetAsmInfo(const PPCTargetMachine &TM) diff --git a/lib/Target/X86/X86TargetAsmInfo.cpp b/lib/Target/X86/X86TargetAsmInfo.cpp index 1735220ae2c..2bb4a6c2272 100644 --- a/lib/Target/X86/X86TargetAsmInfo.cpp +++ b/lib/Target/X86/X86TargetAsmInfo.cpp @@ -68,6 +68,13 @@ X86TargetAsmInfo::X86TargetAsmInfo(const X86TargetMachine &TM) { WeakRefDirective = "\t.weak_reference\t"; HiddenDirective = "\t.private_extern\t"; + // In non-PIC modes, emit a special label before jump tables so that the + // linker can perform more accurate dead code stripping. + if (TM.getRelocationModel() != Reloc::PIC_) { + // Emit a local label that is preserved until the linker runs. + JumpTableSpecialLabelPrefix = "l"; + } + NeedsSet = true; DwarfAbbrevSection = ".section __DWARF,__debug_abbrev,regular,debug"; DwarfInfoSection = ".section __DWARF,__debug_info,regular,debug";