[Turbofan] Add ARM support for simd128 moves and swaps.

src/arm/assembler-arm.h

Index: src/arm/assembler-arm.h
diff --git a/src/arm/assembler-arm.h b/src/arm/assembler-arm.h
index 1283c3984a6454a5faa033df5a844a63a7f39a4d..32d79a39e0a52398ad577082bc1c5c938d0fab64 100644
--- a/src/arm/assembler-arm.h
+++ b/src/arm/assembler-arm.h
@@ -302,6 +302,20 @@ struct QwNeonRegister {
     *m = (encoded_code & 0x10) >> 4;
     *vm = encoded_code & 0x0F;
   }
+  DwVfpRegister low() const {
+    DwVfpRegister reg;
+    reg.reg_code = reg_code * 2;
+
+    DCHECK(reg.is_valid());
+    return reg;
+  }
+  DwVfpRegister high() const {
+    DwVfpRegister reg;
+    reg.reg_code = reg_code * 2 + 1;
+
+    DCHECK(reg.is_valid());
+    return reg;
+  }
 
   int reg_code;
 };
@@ -405,6 +419,7 @@ const QwNeonRegister q15 = { 15 };
 #define kLastCalleeSavedDoubleReg d15
 #define kDoubleRegZero d14
 #define kScratchDoubleReg d15
+#define kScratchQuadReg q7  // After use, kDoubleRegZero must be reset to 0.
 
 
 // Coprocessor register
@@ -1133,6 +1148,8 @@ class Assembler : public AssemblerBase {
   void vmov(const DwVfpRegister dst,
             const DwVfpRegister src,
             const Condition cond = al);
+  void vmov(const QwNeonRegister dst,
+            const QwNeonRegister src);
   void vmov(const DwVfpRegister dst,
             const VmovIndex index,
             const Register src,
@@ -1313,8 +1330,8 @@ class Assembler : public AssemblerBase {
             const NeonMemOperand& dst);
   void vmovl(NeonDataType dt, QwNeonRegister dst, DwVfpRegister src);
 
-  // Currently, vswp supports only D0 to D31.
-  void vswp(DwVfpRegister srcdst0, DwVfpRegister srcdst1);
+  void vswp(DwVfpRegister dst, DwVfpRegister src);

[martyn.capewell, 2016/11/23 20:08:46]

I guess this is a deliberate change, but I named the arguments srcdst here to
make it clear that we read and write both arguments.

[bbudge, 2016/11/24 02:22:53]

I'll change it back.

+  void vswp(QwNeonRegister dst, QwNeonRegister src);
 
   // Pseudo instructions
 
@@ -1611,6 +1628,12 @@ class Assembler : public AssemblerBase {
            (reg.reg_code < LowDwVfpRegister::kMaxNumLowRegisters);
   }
 
+  bool VfpRegisterIsAvailable(QwNeonRegister reg) {
+    DCHECK(reg.is_valid());
+    return IsEnabled(VFP32DREGS) ||
+           (reg.reg_code < LowDwVfpRegister::kMaxNumLowRegisters / 2);
+  }
+
  private:
   int next_buffer_check_;  // pc offset of next buffer check