Revert trunk to bleeding_edge at r12484

src/arm/assembler-arm.cc

Index: src/arm/assembler-arm.cc
diff --git a/src/arm/assembler-arm.cc b/src/arm/assembler-arm.cc
index 78db06d2675f0b2231baa4cb96a7c1b7a97bb7f2..30a8830c9eae0a219d694a38788ac8c4c972fa18 100644
--- a/src/arm/assembler-arm.cc
+++ b/src/arm/assembler-arm.cc
@@ -1975,7 +1975,6 @@ static bool FitsVMOVDoubleImmediate(double d, uint32_t *encoding) {
 
 void Assembler::vmov(const DwVfpRegister dst,
                      double imm,
-                     const Register scratch,
                      const Condition cond) {
   // Dd = immediate
   // Instruction details available in ARM DDI 0406B, A8-640.
@@ -1990,22 +1989,22 @@ void Assembler::vmov(const DwVfpRegister dst,
     // using vldr from a constant pool.
     uint32_t lo, hi;
     DoubleAsTwoUInt32(imm, &lo, &hi);
-    mov(ip, Operand(lo));
 
-    if (scratch.is(no_reg)) {
+    if (lo == hi) {
+      // If the lo and hi parts of the double are equal, the literal is easier
+      // to create. This is the case with 0.0.
+      mov(ip, Operand(lo));
+      vmov(dst, ip, ip);
+    } else {
       // Move the low part of the double into the lower of the corresponsing S
       // registers of D register dst.
+      mov(ip, Operand(lo));
       vmov(dst.low(), ip, cond);
 
       // Move the high part of the double into the higher of the corresponsing S
       // registers of D register dst.
       mov(ip, Operand(hi));
       vmov(dst.high(), ip, cond);
-    } else {
-      // Move the low and high parts of the double to a D register in one
-      // instruction.
-      mov(scratch, Operand(hi));
-      vmov(dst, ip, scratch, cond);
     }
   }
 }