ARM: optimize inlined doubles

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 17bf4f93ac7b7a5cf054f7afeadf06b8af3ee245..eae38be6ebb6a2be61f7e35a2be6fc46a91a4071 100644
--- a/src/arm/assembler-arm.cc
+++ b/src/arm/assembler-arm.cc
@@ -2545,27 +2545,20 @@ void Assembler::vmov(const DwVfpRegister dst,
     uint32_t lo, hi;
     DoubleAsTwoUInt32(imm, &lo, &hi);
 
-    if (scratch.is(no_reg)) {
-      if (dst.code() < 16) {
-        const LowDwVfpRegister loc = LowDwVfpRegister::from_code(dst.code());
-        // Move the low part of the double into the lower of the corresponsing S
-        // registers of D register dst.
-        mov(ip, Operand(lo));
-        vmov(loc.low(), ip);
-
-        // Move the high part of the double into the higher of the
-        // corresponsing S registers of D register dst.
-        mov(ip, Operand(hi));
-        vmov(loc.high(), ip);
+    if (lo == hi) {
+      // Move the low and high parts of the double to a D register in one
+      // instruction.
+      mov(ip, Operand(lo));
+      vmov(dst, ip, ip);
+    } else if (scratch.is(no_reg)) {
+      mov(ip, Operand(lo));
+      vmov(dst, VmovIndexLo, ip);
+      if ((lo & 0xffff) == (hi & 0xffff)) {
+        movt(ip, hi >> 16);
       } else {
-        // D16-D31 does not have S registers, so move the low and high parts
-        // directly to the D register using vmov.32.
-        // Note: This may be slower, so we only do this when we have to.
-        mov(ip, Operand(lo));
-        vmov(dst, VmovIndexLo, ip);
         mov(ip, Operand(hi));
-        vmov(dst, VmovIndexHi, ip);
       }
+      vmov(dst, VmovIndexHi, ip);
     } else {
       // Move the low and high parts of the double to a D register in one
       // instruction.