AMDGPU/SI: Refactor fixup handling for constant addrspace variables

Summary:
We now use a standard fixup type applying the pc-relative address of
constant address space variables, and we have the GlobalAddress lowering
code add the required 4 byte offset to the global address rather than
doing it as part of the fixup.

This refactoring will make it easier to use the same code for global
address space variables and also simplifies the code.

Reviewers: arsenm, kzhuravl

Subscribers: arsenm, kzhuravl, llvm-commits

Differential Revision: http://reviews.llvm.org/D21154

llvm-svn: 272675

1 files changed, 4 insertions, 5 deletions

diff --git a/llvm/lib/Target/AMDGPU/MCTargetDesc/SIMCCodeEmitter.cpp b/llvm/lib/Target/AMDGPU/MCTargetDesc/SIMCCodeEmitter.cpp
index 533a54c1a8b..52787b64f7e 100644
--- a/llvm/lib/Target/AMDGPU/MCTargetDesc/SIMCCodeEmitter.cpp
+++ b/llvm/lib/Target/AMDGPU/MCTargetDesc/SIMCCodeEmitter.cpp
@@ -248,14 +248,13 @@ uint64_t SIMCCodeEmitter::getMachineOpValue(const MCInst &MI,
     return MRI.getEncodingValue(MO.getReg());
 
   if (MO.isExpr()) {
-    const MCSymbolRefExpr *Expr = cast<MCSymbolRefExpr>(MO.getExpr());
-    const MCSymbol &Sym = Expr->getSymbol();
+    const MCSymbolRefExpr *Expr = dyn_cast<MCSymbolRefExpr>(MO.getExpr());
     MCFixupKind Kind;
-    if (Sym.isExternal())
+    if (Expr && Expr->getSymbol().isExternal())
       Kind = FK_Data_4;
     else
-      Kind = (MCFixupKind)AMDGPU::fixup_si_rodata;
-    Fixups.push_back(MCFixup::create(4, Expr, Kind, MI.getLoc()));
+      Kind = FK_PCRel_4;
+    Fixups.push_back(MCFixup::create(4, MO.getExpr(), Kind, MI.getLoc()));
   }
 
   // Figure out the operand number, needed for isSrcOperand check