Replace a set of Hydrogen instructions with rotate instructions on ARM

src/arm/simulator-arm.cc

Index: src/arm/simulator-arm.cc
===================================================================
--- src/arm/simulator-arm.cc	(revision 12582)
+++ src/arm/simulator-arm.cc	(working copy)
@@ -1498,10 +1498,18 @@
       }
 
       case ROR: {
-        UNIMPLEMENTED();
+        if (shift_amount == 0) {
+          *carry_out = c_flag_;
+        } else {
+          int32_t left = result >> shift_amount;

[Erik Corry, 2012/09/27 14:45:44]

How does this work with a negative input?

+          int32_t right = result << (32 - shift_amount);
+          result = right | left;
+          *carry_out = false;

[ulan, 2012/09/27 14:55:30]

The carry_out should contain the last shifted bit according to the spec.

+        }
         break;
       }
 

[ulan, 2012/09/27 14:55:30]

We can remove this empty line.

+
       default: {
         UNREACHABLE();
         break;