Port Math.pow inlining to ARM.

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 8b3c1a423614a3a719498fa21de4b62b6a345bb8..b35dc7c145d884c074bd6582419293f7015fd954 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -3122,61 +3122,34 @@ void LCodeGen::DoMathPowHalf(LUnaryMathOperation* instr) {
 
 
 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(0, 2, scratch);
-    __ SetCallCDoubleArguments(ToDoubleRegister(left),
-                               ToDoubleRegister(right));
-    __ CallCFunction(
-        ExternalReference::power_double_double_function(isolate()), 0, 2);
-  } else if (exponent_type.IsInteger32()) {
-    ASSERT(ToRegister(right).is(r0));
-    // Prepare arguments and call C function.
-    __ PrepareCallCFunction(1, 1, scratch);
-    __ SetCallCDoubleArguments(ToDoubleRegister(left), ToRegister(right));
-    __ CallCFunction(
-        ExternalReference::power_double_int_function(isolate()), 1, 1);
-  } else {
-    ASSERT(exponent_type.IsTagged());
-    ASSERT(instr->hydrogen()->left()->representation().IsDouble());
-
-    Register right_reg = ToRegister(right);
-
-    // Check for smi on the right hand side.
-    Label non_smi, call;
-    __ JumpIfNotSmi(right_reg, &non_smi);
-
-    // Untag smi and convert it to a double.
-    __ SmiUntag(right_reg);
-    SwVfpRegister single_scratch = double_scratch0().low();
-    __ vmov(single_scratch, right_reg);
-    __ vcvt_f64_s32(result_reg, single_scratch);
-    __ jmp(&call);
-
-    // Heap number map check.
-    __ bind(&non_smi);
-    __ ldr(scratch, FieldMemOperand(right_reg, HeapObject::kMapOffset));
+  // Having marked this as a call, we can use any registers.
+  // Just make sure that the input/output registers are the expected ones.
+  ASSERT(!instr->InputAt(1)->IsDoubleRegister() ||
+         ToDoubleRegister(instr->InputAt(1)).is(d2));
+  ASSERT(!instr->InputAt(1)->IsRegister() ||
+         ToRegister(instr->InputAt(1)).is(r2));
+  ASSERT(ToDoubleRegister(instr->InputAt(0)).is(d1));
+  ASSERT(ToDoubleRegister(instr->result()).is(d3));
+
+  if (exponent_type.IsTagged()) {
+    Label no_deopt;
+    __ JumpIfSmi(r2, &no_deopt);
+    __ ldr(r7, FieldMemOperand(r2, HeapObject::kMapOffset));
     __ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
-    __ cmp(scratch, Operand(ip));
+    __ cmp(r7, Operand(ip));
     DeoptimizeIf(ne, instr->environment());
-    int32_t value_offset = HeapNumber::kValueOffset - kHeapObjectTag;
-    __ add(scratch, right_reg, Operand(value_offset));
-    __ vldr(result_reg, scratch, 0);
-
-    // Prepare arguments and call C function.
-    __ bind(&call);
-    __ PrepareCallCFunction(0, 2, scratch);
-    __ SetCallCDoubleArguments(ToDoubleRegister(left), result_reg);
-    __ CallCFunction(
-        ExternalReference::power_double_double_function(isolate()), 0, 2);
+    __ bind(&no_deopt);
+    MathPowStub stub(MathPowStub::TAGGED);
+    __ CallStub(&stub);
+  } else if (exponent_type.IsInteger32()) {
+    MathPowStub stub(MathPowStub::INTEGER);
+    __ CallStub(&stub);
+  } else {
+    ASSERT(exponent_type.IsDouble());
+    MathPowStub stub(MathPowStub::DOUBLE);
+    __ CallStub(&stub);
   }
-  // Store the result in the result register.
-  __ GetCFunctionDoubleResult(result_reg);
 }