[XCore] Add support for the "m" inline asm constraint.

Summary:
This provides support for CP and DP relative global accesses in inline
asm.

Reviewers: robertlytton

Reviewed By: robertlytton

Differential Revision: http://llvm-reviews.chandlerc.com/D2943

llvm-svn: 203129

1 files changed, 26 insertions, 1 deletions

diff --git a/llvm/lib/Target/XCore/XCoreISelDAGToDAG.cpp b/llvm/lib/Target/XCore/XCoreISelDAGToDAG.cpp
index e28f84fec2a..5b0fcfa15e4 100644
--- a/llvm/lib/Target/XCore/XCoreISelDAGToDAG.cpp
+++ b/llvm/lib/Target/XCore/XCoreISelDAGToDAG.cpp
@@ -66,7 +66,10 @@ namespace {
 
     // Complex Pattern Selectors.
     bool SelectADDRspii(SDValue Addr, SDValue &Base, SDValue &Offset);
-    
+
+    bool SelectInlineAsmMemoryOperand(const SDValue &Op, char ConstraintCode,
+                                      std::vector<SDValue> &OutOps) override;
+
     virtual const char *getPassName() const {
       return "XCore DAG->DAG Pattern Instruction Selection";
     } 
@@ -106,6 +109,28 @@ bool XCoreDAGToDAGISel::SelectADDRspii(SDValue Addr, SDValue &Base,
   return false;
 }
 
+bool XCoreDAGToDAGISel::
+SelectInlineAsmMemoryOperand(const SDValue &Op, char ConstraintCode,
+                             std::vector<SDValue> &OutOps) {
+  SDValue Reg;
+  switch (ConstraintCode) {
+  default: return true;
+  case 'm': // Memory.
+    switch (Op.getOpcode()) {
+    default: return true;
+    case XCoreISD::CPRelativeWrapper:
+      Reg = CurDAG->getRegister(XCore::CP, MVT::i32);
+      break;
+    case XCoreISD::DPRelativeWrapper:
+      Reg = CurDAG->getRegister(XCore::DP, MVT::i32);
+      break;
+    }
+  }
+  OutOps.push_back(Reg);
+  OutOps.push_back(Op.getOperand(0));
+  return false;
+}
+
 SDNode *XCoreDAGToDAGISel::Select(SDNode *N) {
   SDLoc dl(N);
   switch (N->getOpcode()) {