ARM: Implement MathPowStub and DoMathPowHalf.

src/arm/lithium-codegen-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 727 matching lines @@
     case CodeStub::SubString: {
       SubStringStub stub;
       CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
       break;
     }
     case CodeStub::StringCharAt: {
       StringCharAtStub stub;
       CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
       break;
     }
-    case CodeStub::MathPow: {
-      Abort("MathPowStub unimplemented.");
-      break;
-    }
     case CodeStub::NumberToString: {
       NumberToStringStub stub;
       CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
       break;
     }
     case CodeStub::StringAdd: {
       StringAddStub stub(NO_STRING_ADD_FLAGS);
       CallCode(stub.GetCode(), RelocInfo::CODE_TARGET, instr);
       break;
     }
@@ skipping 1877 matching lines @@
 }
 
 
 void LCodeGen::DoMathSqrt(LUnaryMathOperation* instr) {
   DoubleRegister input = ToDoubleRegister(instr->InputAt(0));
   ASSERT(ToDoubleRegister(instr->result()).is(input));
   __ vsqrt(input, input);
 }
 
 
+void LCodeGen::DoMathPowHalf(LUnaryMathOperation* instr) {
+  DoubleRegister input = ToDoubleRegister(instr->InputAt(0));
+  Register scratch = scratch0();
+  SwVfpRegister single_scratch = double_scratch0().low();
+  DoubleRegister double_scratch = double_scratch0();
+  ASSERT(ToDoubleRegister(instr->result()).is(input));
+
+  // Add +0 to convert -0 to +0.
+  __ eor(scratch, scratch, Operand(scratch));

[Søren Thygesen Gjesse, 2011/03/08 10:05:12]

On ARM just using mov(scratch, Operand(0)) should be fine for zeroing a
register.

[Karl Klose, 2011/03/08 10:29:00]

Done.

+  __ vmov(single_scratch, scratch);
+  __ vcvt_f64_s32(double_scratch, single_scratch);
+  __ vadd(input, input, double_scratch);
+  __ vsqrt(input, input);
+}
+
+
 void LCodeGen::DoPower(LPower* instr) {
   LOperand* left = instr->InputAt(0);
   LOperand* right = instr->InputAt(1);
   Register scratch = scratch0();
   DoubleRegister result_reg = ToDoubleRegister(instr->result());
   Representation exponent_type = instr->hydrogen()->right()->representation();
   if (exponent_type.IsDouble()) {
     // Prepare arguments and call C function.
     __ PrepareCallCFunction(4, scratch);
     __ vmov(r0, r1, ToDoubleRegister(left));
@@ skipping 76 matching lines @@
       break;
     case kMathFloor:
       DoMathFloor(instr);
       break;
     case kMathRound:
       DoMathRound(instr);
       break;
     case kMathSqrt:
       DoMathSqrt(instr);
       break;
+    case kMathPowHalf:
+      DoMathPowHalf(instr);
+      break;
     case kMathCos:
       DoMathCos(instr);
       break;
     case kMathSin:
       DoMathSin(instr);
       break;
     case kMathLog:
       DoMathLog(instr);
       break;
     default:
@@ skipping 1078 matching lines @@
   ASSERT(!environment->HasBeenRegistered());
   RegisterEnvironmentForDeoptimization(environment);
   ASSERT(osr_pc_offset_ == -1);
   osr_pc_offset_ = masm()->pc_offset();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal