ARM: Improve register allocation and constraints....

src/arm/macro-assembler-arm.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 723 matching lines @@
 
 void MacroAssembler::VFPCompareAndLoadFlags(const DwVfpRegister src1,
                                             const double src2,
                                             const Register fpscr_flags,
                                             const Condition cond) {
   // Compare and load FPSCR.
   vcmp(src1, src2, cond);
   vmrs(fpscr_flags, cond);
 }
 
+void MacroAssembler::Vmov(const DwVfpRegister dst,
+                          const double imm,
+                          const Condition cond) {
+  ASSERT(CpuFeatures::IsEnabled(VFP3));
+  static const DoubleRepresentation minus_zero(-0.0);
+  static const DoubleRepresentation zero(0.0);
+  DoubleRepresentation value(imm);
+  // Handle special values first.
+  if (imm == 255.0) {
+    vmov(dst, kDoubleReg255, cond);
+  } else if (value.bits == minus_zero.bits) {
+    vmov(dst, kDoubleRegMinusZero, cond);
+  } else if (value.bits == zero.bits) {
+    vmov(dst, kDoubleRegZero, cond);
+  } else {
+    vmov(dst, imm, cond);
+  }
+}
+
 
 void MacroAssembler::EnterFrame(StackFrame::Type type) {
   // r0-r3: preserved
   stm(db_w, sp, cp.bit() | fp.bit() | lr.bit());
   mov(ip, Operand(Smi::FromInt(type)));
   push(ip);
   mov(ip, Operand(CodeObject()));
   push(ip);
   add(fp, sp, Operand(3 * kPointerSize));  // Adjust FP to point to saved FP.
 }
@@ skipping 2338 matching lines @@
 }
 
 
 void MacroAssembler::ClampDoubleToUint8(Register result_reg,
                                         DoubleRegister input_reg,
                                         DoubleRegister temp_double_reg) {
   Label above_zero;
   Label done;
   Label in_bounds;
 
-  vmov(temp_double_reg, 0.0);
+  Vmov(temp_double_reg, 0.0);
   VFPCompareAndSetFlags(input_reg, temp_double_reg);
   b(gt, &above_zero);
 
   // Double value is less than zero, NaN or Inf, return 0.
   mov(result_reg, Operand(0));
   b(al, &done);
 
   // Double value is >= 255, return 255.
   bind(&above_zero);
-  vmov(temp_double_reg, 255.0);
+  Vmov(temp_double_reg, 255.0);
   VFPCompareAndSetFlags(input_reg, temp_double_reg);
   b(le, &in_bounds);
   mov(result_reg, Operand(255));
   b(al, &done);
 
   // In 0-255 range, round and truncate.
   bind(&in_bounds);
-  vmov(temp_double_reg, 0.5);
+  Vmov(temp_double_reg, 0.5);
   vadd(temp_double_reg, input_reg, temp_double_reg);
   vcvt_u32_f64(s0, temp_double_reg);
   vmov(result_reg, s0);
   bind(&done);
 }
 
 
 void MacroAssembler::LoadInstanceDescriptors(Register map,
                                              Register descriptors) {
   ldr(descriptors,
@@ skipping 40 matching lines @@
 void CodePatcher::EmitCondition(Condition cond) {
   Instr instr = Assembler::instr_at(masm_.pc_);
   instr = (instr & ~kCondMask) | cond;
   masm_.emit(instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM