In the X86 back end, getMemoryOperandNo() returns the offset

into the operand array of the start of the memory reference descriptor.

Additional code in EncodeInstruction provides an additional adjustment.

This patch places that additional code in a separate function,
called getOperandBias, so that any caller of getMemoryOperandNo
can also call getOperandBias.

llvm-svn: 179211

2 files changed, 22 insertions, 12 deletions

diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86BaseInfo.h b/llvm/lib/Target/X86/MCTargetDesc/X86BaseInfo.h
index 36695600707..980421d6a3e 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86BaseInfo.h
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86BaseInfo.h
@@ -20,6 +20,7 @@
 #include "X86MCTargetDesc.h"
 #include "llvm/Support/DataTypes.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "llvm/MC/MCInstrInfo.h"
 
 namespace llvm {
 
@@ -41,7 +42,6 @@ namespace X86 {
     AddrNumOperands = 5
   };
 } // end namespace X86;
- 
 
 /// X86II - This namespace holds all of the target specific flags that
 /// instruction info tracks.
@@ -521,6 +521,26 @@ namespace X86II {
     }
   }
 
+  /// getOperandBias - compute any additional adjustment needed to
+  ///                  the offset to the start of the memory operand
+  ///                  in this instruction.
+  /// If this is a two-address instruction,skip one of the register operands.
+  /// FIXME: This should be handled during MCInst lowering.
+  inline int getOperandBias(const MCInstrDesc& Desc)
+  {
+    unsigned NumOps = Desc.getNumOperands();
+    unsigned CurOp = 0;
+    if (NumOps > 1 && Desc.getOperandConstraint(1, MCOI::TIED_TO) == 0)
+      ++CurOp;
+    else if (NumOps > 3 && Desc.getOperandConstraint(2, MCOI::TIED_TO) == 0) {
+      assert(Desc.getOperandConstraint(NumOps - 1, MCOI::TIED_TO) == 1);
+      // Special case for GATHER with 2 TIED_TO operands
+      // Skip the first 2 operands: dst, mask_wb
+      CurOp += 2;
+    }
+    return CurOp;
+  }
+
   /// getMemoryOperandNo - The function returns the MCInst operand # for the
   /// first field of the memory operand.  If the instruction doesn't have a
   /// memory operand, this returns -1.
diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
index 776cee1e35c..d1ea2fe368a 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
@@ -979,18 +979,8 @@ EncodeInstruction(const MCInst &MI, raw_ostream &OS,
   if ((TSFlags & X86II::FormMask) == X86II::Pseudo)
     return;
 
-  // If this is a two-address instruction, skip one of the register operands.
-  // FIXME: This should be handled during MCInst lowering.
   unsigned NumOps = Desc.getNumOperands();
-  unsigned CurOp = 0;
-  if (NumOps > 1 && Desc.getOperandConstraint(1, MCOI::TIED_TO) == 0)
-    ++CurOp;
-  else if (NumOps > 3 && Desc.getOperandConstraint(2, MCOI::TIED_TO) == 0) {
-    assert(Desc.getOperandConstraint(NumOps - 1, MCOI::TIED_TO) == 1);
-    // Special case for GATHER with 2 TIED_TO operands
-    // Skip the first 2 operands: dst, mask_wb
-    CurOp += 2;
-  }
+  unsigned CurOp = X86II::getOperandBias(Desc);
 
   // Keep track of the current byte being emitted.
   unsigned CurByte = 0;