[mips] Weaken asm predicate for memory offsets

The isMemWithSimmOffset predicate rejects relocations which is incorrect
behaviour. Linkers and other tools should handle|warn|error when the
field overflows.

Reviewers: dsanders, vkalintiris

Differential Revision: http://reviews.llvm.org/D20727

llvm-svn: 270995

1 files changed, 7 insertions, 3 deletions

diff --git a/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp b/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
index b22a7fb0078..523cdd4098a 100644
--- a/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
+++ b/llvm/lib/Target/Mips/AsmParser/MipsAsmParser.cpp
@@ -1073,11 +1073,15 @@ public:
   bool isConstantMemOff() const {
     return isMem() && isa<MCConstantExpr>(getMemOff());
   }
+  // Allow relocation operators.
+  // FIXME: This predicate and others need to look through binary expressions
+  //        and determine whether a Value is a constant or not.
   template <unsigned Bits, unsigned ShiftAmount = 0>
   bool isMemWithSimmOffset() const {
-    return isMem() && isConstantMemOff() &&
-           isShiftedInt<Bits, ShiftAmount>(getConstantMemOff()) &&
-           getMemBase()->isGPRAsmReg();
+    return isMem() && getMemBase()->isGPRAsmReg() &&
+           (isa<MCTargetExpr>(getMemOff()) ||
+            (isConstantMemOff() &&
+             isShiftedInt<Bits, ShiftAmount>(getConstantMemOff())));
   }
   bool isMemWithGRPMM16Base() const {
     return isMem() && getMemBase()->isMM16AsmReg();