1 files changed, 19 insertions, 1 deletions
diff --git a/lib/Target/ARM/ARMAddressingModes.h b/lib/Target/ARM/ARMAddressingModes.h
index 9e086ca5c5..1798768ea4 100644
--- a/lib/Target/ARM/ARMAddressingModes.h
+++ b/lib/Target/ARM/ARMAddressingModes.h
@@ -35,6 +35,10 @@ namespace ARM_AM {
     add = '+', sub = '-'
   };
 
+  static inline const char *getAddrOpcStr(AddrOpc Op) {
+    return Op == sub ? "-" : "";
+  }
+
   static inline const char *getShiftOpcStr(ShiftOpc Op) {
     switch (Op) {
     default: assert(0 && "Unknown shift opc!");
@@ -127,6 +131,20 @@ namespace ARM_AM {
     return (Imm >> 8) * 2;
   }
 
+  /// getSOImmValOneRotate - Try to handle Imm with an immediate shifter
+  /// operand, computing the rotate amount to use.  If this immediate value
+  /// cannot be handled with a single shifter-op, return 0.
+  static inline unsigned getSOImmValOneRotate(unsigned Imm) {
+    // A5.2.4 Constants with multiple encodings
+    // The lowest unsigned value of rotation wins!
+    for (unsigned R = 1; R <= 15; ++R)
+      if ((Imm & rotr32(~255U, 2*R)) == 0)
+        return 2*R;
+
+    // Failed to find a suitable rotate amount.
+    return 0;
+  }
+
   /// getSOImmValRotate - Try to handle Imm with an immediate shifter operand,
   /// computing the rotate amount to use.  If this immediate value cannot be
   /// handled with a single shifter-op, determine a good rotate amount that will
@@ -179,7 +197,7 @@ namespace ARM_AM {
     // of zero.
     if ((Arg & ~255U) == 0) return Arg;
 
-    unsigned RotAmt = getSOImmValRotate(Arg);
+    unsigned RotAmt = getSOImmValOneRotate(Arg);
 
     // If this cannot be handled with a single shifter_op, bail out.
     if (rotr32(~255U, RotAmt) & Arg)