[builtins] Remove unused MathPowTagged and MathPowInteger descriptors.

The MathPowInternal builtin is now only called directly from the
code-generator. Also, this patch takes the opportunity to cleanup the builtin
for arm and arm64 a little.

Change-Id: If53edcecd42b227ef74ee817bc5d7fbbcea8b0e2
Reviewed-on: https://chromium-review.googlesource.com/1076127Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Pierre Langlois <pierre.langlois@arm.com>
Cr-Commit-Position: refs/heads/master@{#53442}

src/arm/interface-descriptors-arm.cc

@@ -59,13 +59,6 @@ const Register StoreTransitionDescriptor::MapRegister() { return r5; }
 const Register ApiGetterDescriptor::HolderRegister() { return r0; }
 const Register ApiGetterDescriptor::CallbackRegister() { return r3; }
 
-const Register MathPowTaggedDescriptor::exponent() { return r2; }
-
-const Register MathPowIntegerDescriptor::exponent() {
-  return MathPowTaggedDescriptor::exponent();
-}
-
-
 const Register GrowArrayElementsDescriptor::ObjectRegister() { return r0; }
 const Register GrowArrayElementsDescriptor::KeyRegister() { return r3; }
 

src/arm64/interface-descriptors-arm64.cc

@@ -59,12 +59,6 @@ const Register StoreTransitionDescriptor::MapRegister() { return x5; }
 const Register ApiGetterDescriptor::HolderRegister() { return x0; }
 const Register ApiGetterDescriptor::CallbackRegister() { return x3; }
 
-const Register MathPowTaggedDescriptor::exponent() { return x11; }
-
-
-const Register MathPowIntegerDescriptor::exponent() { return x12; }
-
-
 const Register GrowArrayElementsDescriptor::ObjectRegister() { return x0; }
 const Register GrowArrayElementsDescriptor::KeyRegister() { return x3; }
 

src/builtins/arm/builtins-arm.cc

@@ -2834,20 +2834,20 @@ void Builtins::Generate_DoubleToI(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_MathPowInternal(MacroAssembler* masm) {
-  const Register exponent = MathPowTaggedDescriptor::exponent();
-  DCHECK(exponent == r2);
   const LowDwVfpRegister double_base = d0;
   const LowDwVfpRegister double_exponent = d1;
   const LowDwVfpRegister double_result = d2;
   const LowDwVfpRegister double_scratch = d3;
   const SwVfpRegister single_scratch = s6;
-  const Register scratch = r9;
-  const Register scratch2 = r4;
+  // Avoid using Registers r0-r3 as they may be needed when calling to C if the
+  // ABI is softfloat.
+  const Register integer_exponent = r4;
+  const Register scratch = r5;
 
   Label call_runtime, done, int_exponent;
 
   // Detect integer exponents stored as double.
-  __ TryDoubleToInt32Exact(scratch, double_exponent, double_scratch);
+  __ TryDoubleToInt32Exact(integer_exponent, double_exponent, double_scratch);
   __ b(eq, &int_exponent);
 
   __ push(lr);
@@ -2864,16 +2864,13 @@ void Builtins::Generate_MathPowInternal(MacroAssembler* masm) {
   // Calculate power with integer exponent.
   __ bind(&int_exponent);
 
-  // Get two copies of exponent in the registers scratch and exponent.
-  // Exponent has previously been stored into scratch as untagged integer.
-  __ mov(exponent, scratch);
-
   __ vmov(double_scratch, double_base);  // Back up base.
-  __ vmov(double_result, Double(1.0), scratch2);
+  __ vmov(double_result, Double(1.0), scratch);
 
   // Get absolute value of exponent.
-  __ cmp(scratch, Operand::Zero());
-  __ rsb(scratch, scratch, Operand::Zero(), LeaveCC, mi);
+  __ cmp(integer_exponent, Operand::Zero());
+  __ mov(scratch, integer_exponent);
+  __ rsb(scratch, integer_exponent, Operand::Zero(), LeaveCC, mi);
 
   Label while_true;
   __ bind(&while_true);
@@ -2882,7 +2879,7 @@ void Builtins::Generate_MathPowInternal(MacroAssembler* masm) {
   __ vmul(double_scratch, double_scratch, double_scratch, ne);
   __ b(ne, &while_true);
 
-  __ cmp(exponent, Operand::Zero());
+  __ cmp(integer_exponent, Operand::Zero());
   __ b(ge, &done);
   __ vmov(double_scratch, Double(1.0), scratch);
   __ vdiv(double_result, double_scratch, double_result);
@@ -2892,7 +2889,7 @@ void Builtins::Generate_MathPowInternal(MacroAssembler* masm) {
   __ b(ne, &done);
   // double_exponent may not containe the exponent value if the input was a
   // smi.  We set it with exponent value before bailing out.
-  __ vmov(single_scratch, exponent);
+  __ vmov(single_scratch, integer_exponent);
   __ vcvt_f64_s32(double_exponent, single_scratch);
 
   // Returning or bailing out.

src/builtins/arm64/builtins-arm64.cc

@@ -3326,16 +3326,7 @@ void Builtins::Generate_DoubleToI(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_MathPowInternal(MacroAssembler* masm) {
-  // Stack on entry:
-  // sp[0]: Exponent (as a tagged value).
-  // sp[1]: Base (as a tagged value).
-  //
-  // The (tagged) result will be returned in x0, as a heap number.
-
-  Register exponent_tagged = MathPowTaggedDescriptor::exponent();
-  DCHECK(exponent_tagged.is(x11));
-  Register exponent_integer = MathPowIntegerDescriptor::exponent();
-  DCHECK(exponent_integer.is(x12));
+  Register exponent_integer = x12;
   Register saved_lr = x19;
   VRegister result_double = d0;
   VRegister base_double = d0;
@@ -3345,7 +3336,7 @@ void Builtins::Generate_MathPowInternal(MacroAssembler* masm) {
   VRegister scratch0_double = d7;
 
   // A fast-path for integer exponents.
-  Label exponent_is_smi, exponent_is_integer;
+  Label exponent_is_integer;
   // Allocate a heap number for the result, and return it.
   Label done;
 
@@ -3365,24 +3356,12 @@ void Builtins::Generate_MathPowInternal(MacroAssembler* masm) {
     __ B(&done);
   }
 
-  // Handle SMI exponents.
-  __ Bind(&exponent_is_smi);
-  //  x10   base_tagged       The tagged base (input).
-  //  x11   exponent_tagged   The tagged exponent (input).
-  //  d1    base_double       The base as a double.
-  __ SmiUntag(exponent_integer, exponent_tagged);
-
   __ Bind(&exponent_is_integer);
-  //  x10   base_tagged       The tagged base (input).
-  //  x11   exponent_tagged   The tagged exponent (input).
-  //  x12   exponent_integer  The exponent as an integer.
-  //  d1    base_double       The base as a double.
 
   // Find abs(exponent). For negative exponents, we can find the inverse later.
   Register exponent_abs = x13;
   __ Cmp(exponent_integer, 0);
   __ Cneg(exponent_abs, exponent_integer, mi);
-  //  x13   exponent_abs      The value of abs(exponent_integer).
 
   // Repeatedly multiply to calculate the power.
   //  result = 1.0;

src/builtins/ia32/builtins-ia32.cc

@@ -3019,8 +3019,7 @@ void Builtins::Generate_DoubleToI(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_MathPowInternal(MacroAssembler* masm) {
-  const Register exponent = MathPowTaggedDescriptor::exponent();
-  DCHECK(exponent == eax);
+  const Register exponent = eax;
   const Register scratch = ecx;
   const XMMRegister double_result = xmm3;
   const XMMRegister double_base = xmm2;

src/builtins/mips/builtins-mips.cc

@@ -2934,8 +2934,7 @@ void Builtins::Generate_DoubleToI(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_MathPowInternal(MacroAssembler* masm) {
-  const Register exponent = MathPowTaggedDescriptor::exponent();
-  DCHECK(exponent == a2);
+  const Register exponent = a2;
   const DoubleRegister double_base = f2;
   const DoubleRegister double_exponent = f4;
   const DoubleRegister double_result = f0;

src/builtins/mips64/builtins-mips64.cc

@@ -2953,8 +2953,7 @@ void Builtins::Generate_DoubleToI(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_MathPowInternal(MacroAssembler* masm) {
-  const Register exponent = MathPowTaggedDescriptor::exponent();
-  DCHECK(exponent == a2);
+  const Register exponent = a2;
   const DoubleRegister double_base = f2;
   const DoubleRegister double_exponent = f4;
   const DoubleRegister double_result = f0;

src/builtins/ppc/builtins-ppc.cc

@@ -2974,8 +2974,7 @@ void Builtins::Generate_DoubleToI(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_MathPowInternal(MacroAssembler* masm) {
-  const Register exponent = MathPowTaggedDescriptor::exponent();
-  DCHECK(exponent == r5);
+  const Register exponent = r5;
   const DoubleRegister double_base = d1;
   const DoubleRegister double_exponent = d2;
   const DoubleRegister double_result = d3;

src/builtins/s390/builtins-s390.cc

@@ -2970,8 +2970,7 @@ void Builtins::Generate_DoubleToI(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_MathPowInternal(MacroAssembler* masm) {
-  const Register exponent = MathPowTaggedDescriptor::exponent();
-  DCHECK(exponent == r4);
+  const Register exponent = r4;
   const DoubleRegister double_base = d1;
   const DoubleRegister double_exponent = d2;
   const DoubleRegister double_result = d3;

src/builtins/x64/builtins-x64.cc

@@ -2966,8 +2966,7 @@ void Builtins::Generate_DoubleToI(MacroAssembler* masm) {
 }
 
 void Builtins::Generate_MathPowInternal(MacroAssembler* masm) {
-  const Register exponent = MathPowTaggedDescriptor::exponent();
-  DCHECK(exponent == rdx);
+  const Register exponent = rdx;
   const Register scratch = rcx;
   const XMMRegister double_result = xmm3;
   const XMMRegister double_base = xmm2;

src/ia32/interface-descriptors-ia32.cc

@@ -58,13 +58,6 @@ const Register StoreTransitionDescriptor::MapRegister() { return edi; }
 const Register ApiGetterDescriptor::HolderRegister() { return ecx; }
 const Register ApiGetterDescriptor::CallbackRegister() { return eax; }
 
-const Register MathPowTaggedDescriptor::exponent() { return eax; }
-
-const Register MathPowIntegerDescriptor::exponent() {
-  return MathPowTaggedDescriptor::exponent();
-}
-
-
 const Register GrowArrayElementsDescriptor::ObjectRegister() { return eax; }
 const Register GrowArrayElementsDescriptor::KeyRegister() { return ebx; }
 

src/interface-descriptors.cc

@@ -267,18 +267,6 @@ void TypeConversionStackParameterDescriptor::InitializePlatformIndependent(
   data->InitializePlatformIndependent(data->register_param_count(), 1, nullptr);
 }
 
-void MathPowTaggedDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {exponent()};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
-void MathPowIntegerDescriptor::InitializePlatformSpecific(
-    CallInterfaceDescriptorData* data) {
-  Register registers[] = {exponent()};
-  data->InitializePlatformSpecific(arraysize(registers), registers);
-}
-
 void LoadWithVectorDescriptor::InitializePlatformIndependent(
     CallInterfaceDescriptorData* data) {
   // kReceiver, kName, kSlot, kVector

src/interface-descriptors.h

@@ -62,8 +62,6 @@ class PlatformInterfaceDescriptor;
   V(ArgumentAdaptor)                  \
   V(ApiCallback)                      \
   V(ApiGetter)                        \
-  V(MathPowTagged)                    \
-  V(MathPowInteger)                   \
   V(GrowArrayElements)                \
   V(NewArgumentsElements)             \
   V(InterpreterDispatch)              \
@@ -730,22 +728,6 @@ class ApiGetterDescriptor : public CallInterfaceDescriptor {
   static const Register CallbackRegister();
 };
 
-class MathPowTaggedDescriptor : public CallInterfaceDescriptor {
- public:
-  DEFINE_PARAMETERS(kExponent)
-  DECLARE_DESCRIPTOR(MathPowTaggedDescriptor, CallInterfaceDescriptor)
-
-  static const Register exponent();
-};
-
-class MathPowIntegerDescriptor : public CallInterfaceDescriptor {
- public:
-  DEFINE_PARAMETERS(kExponent)
-  DECLARE_DESCRIPTOR(MathPowIntegerDescriptor, CallInterfaceDescriptor)
-
-  static const Register exponent();
-};
-
 // TODO(turbofan): We should probably rename this to GrowFastElementsDescriptor.
 class GrowArrayElementsDescriptor : public CallInterfaceDescriptor {
  public:

src/mips/interface-descriptors-mips.cc

@@ -57,13 +57,6 @@ const Register StoreTransitionDescriptor::MapRegister() { return t1; }
 const Register ApiGetterDescriptor::HolderRegister() { return a0; }
 const Register ApiGetterDescriptor::CallbackRegister() { return a3; }
 
-const Register MathPowTaggedDescriptor::exponent() { return a2; }
-
-const Register MathPowIntegerDescriptor::exponent() {
-  return MathPowTaggedDescriptor::exponent();
-}
-
-
 const Register GrowArrayElementsDescriptor::ObjectRegister() { return a0; }
 const Register GrowArrayElementsDescriptor::KeyRegister() { return a3; }
 

src/mips64/interface-descriptors-mips64.cc

@@ -57,13 +57,6 @@ const Register StoreTransitionDescriptor::MapRegister() { return a5; }
 const Register ApiGetterDescriptor::HolderRegister() { return a0; }
 const Register ApiGetterDescriptor::CallbackRegister() { return a3; }
 
-const Register MathPowTaggedDescriptor::exponent() { return a2; }
-
-const Register MathPowIntegerDescriptor::exponent() {
-  return MathPowTaggedDescriptor::exponent();
-}
-
-
 const Register GrowArrayElementsDescriptor::ObjectRegister() { return a0; }
 const Register GrowArrayElementsDescriptor::KeyRegister() { return a3; }
 

src/ppc/interface-descriptors-ppc.cc

@@ -57,13 +57,6 @@ const Register StoreTransitionDescriptor::MapRegister() { return r8; }
 const Register ApiGetterDescriptor::HolderRegister() { return r3; }
 const Register ApiGetterDescriptor::CallbackRegister() { return r6; }
 
-const Register MathPowTaggedDescriptor::exponent() { return r5; }
-
-const Register MathPowIntegerDescriptor::exponent() {
-  return MathPowTaggedDescriptor::exponent();
-}
-
-
 const Register GrowArrayElementsDescriptor::ObjectRegister() { return r3; }
 const Register GrowArrayElementsDescriptor::KeyRegister() { return r6; }
 

src/s390/interface-descriptors-s390.cc

@@ -57,12 +57,6 @@ const Register StoreTransitionDescriptor::MapRegister() { return r7; }
 const Register ApiGetterDescriptor::HolderRegister() { return r2; }
 const Register ApiGetterDescriptor::CallbackRegister() { return r5; }
 
-const Register MathPowTaggedDescriptor::exponent() { return r4; }
-
-const Register MathPowIntegerDescriptor::exponent() {
-  return MathPowTaggedDescriptor::exponent();
-}
-
 const Register GrowArrayElementsDescriptor::ObjectRegister() { return r2; }
 const Register GrowArrayElementsDescriptor::KeyRegister() { return r5; }
 

src/x64/interface-descriptors-x64.cc

@@ -58,13 +58,6 @@ const Register StoreTransitionDescriptor::MapRegister() { return r11; }
 const Register ApiGetterDescriptor::HolderRegister() { return rcx; }
 const Register ApiGetterDescriptor::CallbackRegister() { return rbx; }
 
-const Register MathPowTaggedDescriptor::exponent() { return rdx; }
-
-const Register MathPowIntegerDescriptor::exponent() {
-  return MathPowTaggedDescriptor::exponent();
-}
-
-
 const Register GrowArrayElementsDescriptor::ObjectRegister() { return rax; }
 const Register GrowArrayElementsDescriptor::KeyRegister() { return rbx; }