[turbofan] Introduce Float64Pow and NumberPow operators.

src/mips/code-stubs-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_MIPS
 
 #include "src/code-stubs.h"
 #include "src/api-arguments.h"
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
@@ skipping 742 matching lines @@
   if (save_doubles()) {
     __ MultiPopFPU(kCallerSavedFPU);
   }
 
   __ MultiPop(kJSCallerSaved | ra.bit());
   __ Ret();
 }
 
 
 void MathPowStub::Generate(MacroAssembler* masm) {
-  const Register base = a1;
   const Register exponent = MathPowTaggedDescriptor::exponent();
   DCHECK(exponent.is(a2));
-  const Register heapnumbermap = t1;
-  const Register heapnumber = v0;
   const DoubleRegister double_base = f2;
   const DoubleRegister double_exponent = f4;
   const DoubleRegister double_result = f0;
   const DoubleRegister double_scratch = f6;
   const FPURegister single_scratch = f8;
   const Register scratch = t5;
   const Register scratch2 = t3;
 
   Label call_runtime, done, int_exponent;
-  if (exponent_type() == ON_STACK) {
-    Label base_is_smi, unpack_exponent;
-    // The exponent and base are supplied as arguments on the stack.
-    // This can only happen if the stub is called from non-optimized code.
-    // Load input parameters from stack to double registers.
-    __ lw(base, MemOperand(sp, 1 * kPointerSize));
-    __ lw(exponent, MemOperand(sp, 0 * kPointerSize));
-
-    __ LoadRoot(heapnumbermap, Heap::kHeapNumberMapRootIndex);
-
-    __ UntagAndJumpIfSmi(scratch, base, &base_is_smi);
-    __ lw(scratch, FieldMemOperand(base, JSObject::kMapOffset));
-    __ Branch(&call_runtime, ne, scratch, Operand(heapnumbermap));
-
-    __ ldc1(double_base, FieldMemOperand(base, HeapNumber::kValueOffset));
-    __ jmp(&unpack_exponent);
-
-    __ bind(&base_is_smi);
-    __ mtc1(scratch, single_scratch);
-    __ cvt_d_w(double_base, single_scratch);
-    __ bind(&unpack_exponent);
-
-    __ UntagAndJumpIfSmi(scratch, exponent, &int_exponent);
-
-    __ lw(scratch, FieldMemOperand(exponent, JSObject::kMapOffset));
-    __ Branch(&call_runtime, ne, scratch, Operand(heapnumbermap));
-    __ ldc1(double_exponent,
-            FieldMemOperand(exponent, HeapNumber::kValueOffset));
-  } else if (exponent_type() == TAGGED) {
+  if (exponent_type() == TAGGED) {
     // Base is already in double_base.
     __ UntagAndJumpIfSmi(scratch, exponent, &int_exponent);
 
     __ ldc1(double_exponent,
             FieldMemOperand(exponent, HeapNumber::kValueOffset));
   }
 
   if (exponent_type() != INTEGER) {
     Label int_exponent_convert;
     // Detect integer exponents stored as double.
     __ EmitFPUTruncate(kRoundToMinusInf,
                        scratch,
                        double_exponent,
                        at,
                        double_scratch,
                        scratch2,
                        kCheckForInexactConversion);
     // scratch2 == 0 means there was no conversion error.
     __ Branch(&int_exponent_convert, eq, scratch2, Operand(zero_reg));
 
-    if (exponent_type() == ON_STACK) {
-      // Detect square root case.  Crankshaft detects constant +/-0.5 at
-      // compile time and uses DoMathPowHalf instead.  We then skip this check
-      // for non-constant cases of +/-0.5 as these hardly occur.
-      Label not_plus_half;
-      // Test for 0.5.
-      __ Move(double_scratch, 0.5);
-      __ BranchF(USE_DELAY_SLOT,
-                 &not_plus_half,
-                 NULL,
-                 ne,
-                 double_exponent,
-                 double_scratch);
-      // double_scratch can be overwritten in the delay slot.
-      // Calculates square root of base.  Check for the special case of
-      // Math.pow(-Infinity, 0.5) == Infinity (ECMA spec, 15.8.2.13).
-      __ Move(double_scratch, static_cast<double>(-V8_INFINITY));
-      __ BranchF(USE_DELAY_SLOT, &done, NULL, eq, double_base, double_scratch);
-      __ neg_d(double_result, double_scratch);
-
-      // Add +0 to convert -0 to +0.
-      __ add_d(double_scratch, double_base, kDoubleRegZero);
-      __ sqrt_d(double_result, double_scratch);
-      __ jmp(&done);
-
-      __ bind(&not_plus_half);
-      __ Move(double_scratch, -0.5);
-      __ BranchF(USE_DELAY_SLOT,
-                 &call_runtime,
-                 NULL,
-                 ne,
-                 double_exponent,
-                 double_scratch);
-      // double_scratch can be overwritten in the delay slot.
-      // Calculates square root of base.  Check for the special case of
-      // Math.pow(-Infinity, -0.5) == 0 (ECMA spec, 15.8.2.13).
-      __ Move(double_scratch, static_cast<double>(-V8_INFINITY));
-      __ BranchF(USE_DELAY_SLOT, &done, NULL, eq, double_base, double_scratch);
-      __ Move(double_result, kDoubleRegZero);
-
-      // Add +0 to convert -0 to +0.
-      __ add_d(double_scratch, double_base, kDoubleRegZero);
-      __ Move(double_result, 1.);
-      __ sqrt_d(double_scratch, double_scratch);
-      __ div_d(double_result, double_result, double_scratch);
-      __ jmp(&done);
-    }
-
     __ push(ra);
     {
       AllowExternalCallThatCantCauseGC scope(masm);
       __ PrepareCallCFunction(0, 2, scratch2);
       __ MovToFloatParameters(double_base, double_exponent);
       __ CallCFunction(
           ExternalReference::power_double_double_function(isolate()),
           0, 2);
     }
     __ pop(ra);
@@ skipping 47 matching lines @@
   // Test whether result is zero.  Bail out to check for subnormal result.
   // Due to subnormals, x^-y == (1/x)^y does not hold in all cases.
   __ BranchF(&done, NULL, ne, double_result, kDoubleRegZero);
 
   // double_exponent may not contain the exponent value if the input was a
   // smi.  We set it with exponent value before bailing out.
   __ mtc1(exponent, single_scratch);
   __ cvt_d_w(double_exponent, single_scratch);
 
   // Returning or bailing out.
-  if (exponent_type() == ON_STACK) {
-    // The arguments are still on the stack.
-    __ bind(&call_runtime);
-    __ TailCallRuntime(Runtime::kMathPowRT);
+  __ push(ra);
+  {
+    AllowExternalCallThatCantCauseGC scope(masm);
+    __ PrepareCallCFunction(0, 2, scratch);
+    __ MovToFloatParameters(double_base, double_exponent);
+    __ CallCFunction(ExternalReference::power_double_double_function(isolate()),
+                     0, 2);
+  }
+  __ pop(ra);
+  __ MovFromFloatResult(double_result);
 
-    // The stub is called from non-optimized code, which expects the result
-    // as heap number in exponent.
-    __ bind(&done);
-    __ AllocateHeapNumber(
-        heapnumber, scratch, scratch2, heapnumbermap, &call_runtime);
-    __ sdc1(double_result,
-            FieldMemOperand(heapnumber, HeapNumber::kValueOffset));
-    DCHECK(heapnumber.is(v0));
-    __ DropAndRet(2);
-  } else {
-    __ push(ra);
-    {
-      AllowExternalCallThatCantCauseGC scope(masm);
-      __ PrepareCallCFunction(0, 2, scratch);
-      __ MovToFloatParameters(double_base, double_exponent);
-      __ CallCFunction(
-          ExternalReference::power_double_double_function(isolate()),
-          0, 2);
-    }
-    __ pop(ra);
-    __ MovFromFloatResult(double_result);
-
-    __ bind(&done);
-    __ Ret();
-  }
+  __ bind(&done);
+  __ Ret();
 }
 
-
 bool CEntryStub::NeedsImmovableCode() {
   return true;
 }
 
 
 void CodeStub::GenerateStubsAheadOfTime(Isolate* isolate) {
   CEntryStub::GenerateAheadOfTime(isolate);
   StoreBufferOverflowStub::GenerateFixedRegStubsAheadOfTime(isolate);
   StubFailureTrampolineStub::GenerateAheadOfTime(isolate);
   CommonArrayConstructorStub::GenerateStubsAheadOfTime(isolate);
@@ skipping 4532 matching lines @@
                            kStackUnwindSpace, kInvalidStackOffset,
                            return_value_operand, NULL);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS