Use .set expression for x86 pic jump table reference to reduce assembly relocation. rdar://7738756
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101085 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/AsmPrinter/X86MCInstLower.cpp b/lib/Target/X86/AsmPrinter/X86MCInstLower.cpp
index 2056e95..9e6cf50 100644
--- a/lib/Target/X86/AsmPrinter/X86MCInstLower.cpp
+++ b/lib/Target/X86/AsmPrinter/X86MCInstLower.cpp
@@ -169,6 +169,15 @@
Expr = MCBinaryExpr::CreateSub(Expr,
MCSymbolRefExpr::Create(GetPICBaseSymbol(), Ctx),
Ctx);
+ if (MO.isJTI() && AsmPrinter.MAI->hasSetDirective()) {
+ // If .set directive is supported, use it to reduce the number of
+ // relocations the assembler will generate for differences between
+ // local labels. This is only safe when the symbols are in the same
+ // section so we are restricting it to jumptable references.
+ MCSymbol *Label = Ctx.CreateTempSymbol();
+ AsmPrinter.OutStreamer.EmitAssignment(Label, Expr);
+ Expr = MCSymbolRefExpr::Create(Label, Ctx);
+ }
break;
}