Fixes Android build by using C++ math header instead of C one.

runtime/vm/simulator_arm64.cc

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-#include <math.h>  // for isnan.
 #include <setjmp.h>
 #include <stdlib.h>
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_ARM64)
 
 // Only build the simulator if not compiling for real ARM hardware.
 #if !defined(HOST_ARCH_ARM64)
 
 #include "vm/simulator.h"
@@ skipping 2421 matching lines @@
         return;
       }
       set_vregisterd(vd, idx, res);
     }
   }
 }
 
 
 static float arm_reciprocal_sqrt_estimate(float a) {
   // From the ARM Architecture Reference Manual A2-87.
-  if (isinf(a) || (fabs(a) >= exp2f(126))) return 0.0;
+  if (std::isinf(a) || (fabs(a) >= exp2f(126))) return 0.0;

[koda, 2014/06/30 20:50:40]

It looks slightly odd to have only one of these in std:: (since we still use
float.h rather than cfloat), but I think that's acceptable.

[siva, 2014/06/30 20:59:34]

I agree too, it does seem odd.

I am wondering if it would be more readable to add a 'vm/math.h' file and in it
have:
#include <cmath>
#define isinf(val) std:isinf(val)
#define isnan(val) std::isnan(val)

[zra, 2014/06/30 20:59:44]

Yah, it does look strange, but hopefully it will mean less work when we pull the
STL out.

[zra, 2014/06/30 22:14:33]

Done.

   else if (a == 0.0) return INFINITY;
-  else if (isnan(a)) return a;
+  else if (std::isnan(a)) return a;
 
   uint32_t a_bits = bit_cast<uint32_t, float>(a);
   uint64_t scaled;
   if (((a_bits >> 23) & 1) != 0) {
     // scaled = '0 01111111101' : operand<22:0> : Zeros(29)
     scaled = (static_cast<uint64_t>(0x3fd) << 52) |
              ((static_cast<uint64_t>(a_bits) & 0x7fffff) << 29);
   } else {
     // scaled = '0 01111111110' : operand<22:0> : Zeros(29)
     scaled = (static_cast<uint64_t>(0x3fe) << 52) |
@@ skipping 28 matching lines @@
 
   // result = 0 : result_exp<7:0> : estimate<51:29>
   int32_t result_bits = ((result_exp & 0xff) << 23) |
       ((bit_cast<uint64_t, double>(estimate) >> 29) & 0x7fffff);
   return bit_cast<float, int32_t>(result_bits);
 }
 
 
 static float arm_recip_estimate(float a) {
   // From the ARM Architecture Reference Manual A2-85.
-  if (isinf(a) || (fabs(a) >= exp2f(126))) return 0.0;
+  if (std::isinf(a) || (fabs(a) >= exp2f(126))) return 0.0;
   else if (a == 0.0) return INFINITY;
-  else if (isnan(a)) return a;
+  else if (std::isnan(a)) return a;
 
   uint32_t a_bits = bit_cast<uint32_t, float>(a);
   // scaled = '0011 1111 1110' : a<22:0> : Zeros(29)
   uint64_t scaled = (static_cast<uint64_t>(0x3fe) << 52) |
                     ((static_cast<uint64_t>(a_bits) & 0x7fffff) << 29);
   // result_exp = 253 - UInt(a<30:23>)
   int32_t result_exp = 253 - ((a_bits >> 23) & 0xff);
   ASSERT((result_exp >= 1) && (result_exp <= 252));
 
   double scaled_d = bit_cast<double, uint64_t>(scaled);
@@ skipping 302 matching lines @@
   } else {
     UnimplementedInstruction(instr);
     return;
   }
 
   n_flag_ = false;
   z_flag_ = false;
   c_flag_ = false;
   v_flag_ = false;
 
-  if (isnan(vn_val) || isnan(vm_val)) {
+  if (std::isnan(vn_val) || std::isnan(vm_val)) {
     c_flag_ = true;
     v_flag_ = true;
   } else if (vn_val == vm_val) {
     z_flag_ = true;
     c_flag_ = true;
   } else if (vn_val < vm_val) {
     n_flag_ = true;
   } else {
     c_flag_ = true;
   }
@@ skipping 220 matching lines @@
   set_register(NULL, kExceptionObjectReg, bit_cast<int64_t>(raw_exception));
   set_register(NULL, kStackTraceObjectReg, bit_cast<int64_t>(raw_stacktrace));
   buf->Longjmp();
 }
 
 }  // namespace dart
 
 #endif  // !defined(HOST_ARCH_ARM64)
 
 #endif  // defined TARGET_ARCH_ARM64