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: 33362
diff --git a/llvm/lib/Target/ARM/ARMTargetAsmInfo.cpp b/llvm/lib/Target/ARM/ARMTargetAsmInfo.cpp
index 65848e5..d70ef6d 100644
--- a/llvm/lib/Target/ARM/ARMTargetAsmInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMTargetAsmInfo.cpp
@@ -33,6 +33,13 @@
LCOMMDirective = "\t.lcomm\t";
COMMDirectiveTakesAlignment = false;
+ // 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";