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.
llvm-svn: 33315
diff --git a/llvm/lib/Target/PowerPC/PPCTargetAsmInfo.cpp b/llvm/lib/Target/PowerPC/PPCTargetAsmInfo.cpp
index b9f5849..b54c9e9 100644
--- a/llvm/lib/Target/PowerPC/PPCTargetAsmInfo.cpp
+++ b/llvm/lib/Target/PowerPC/PPCTargetAsmInfo.cpp
@@ -57,6 +57,13 @@
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/llvm/lib/Target/X86/X86TargetAsmInfo.cpp b/llvm/lib/Target/X86/X86TargetAsmInfo.cpp
index 1735220..2bb4a6c 100644
--- a/llvm/lib/Target/X86/X86TargetAsmInfo.cpp
+++ b/llvm/lib/Target/X86/X86TargetAsmInfo.cpp
@@ -68,6 +68,13 @@
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";