ARM: Use the vsqrt instruction when available...

src/arm/simulator-arm.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
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 // modification, are permitted provided that the following conditions are
 // met:
 //
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 //       notice, this list of conditions and the following disclaimer.
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 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 #include <stdlib.h>
+#include <math.h>
 #include <cstdarg>
 #include "v8.h"
 
 #if defined(V8_TARGET_ARCH_ARM)
 
 #include "disasm.h"
 #include "assembler.h"
 #include "arm/constants-arm.h"
 #include "arm/simulator-arm.h"
 
@@ skipping 2216 matching lines @@
 // The Following ARMv7 VFPv instructions are currently supported.
 // vmov :Sn = Rt
 // vmov :Rt = Sn
 // vcvt: Dd = Sm
 // vcvt: Sd = Dm
 // Dd = vadd(Dn, Dm)
 // Dd = vsub(Dn, Dm)
 // Dd = vmul(Dn, Dm)
 // Dd = vdiv(Dn, Dm)
 // vcmp(Dd, Dm)
-// VMRS
+// vmrs
+// Dd = vsqrt(Dm)
 void Simulator::DecodeTypeVFP(Instr* instr) {
   ASSERT((instr->TypeField() == 7) && (instr->Bit(24) == 0x0) );
   ASSERT(instr->Bits(11, 9) == 0x5);
 
   int vm = instr->VmField();
   int vd = instr->VdField();
   int vn = instr->VnField();
 
   if (instr->Bit(4) == 0) {
     if (instr->Opc1Field() == 0x7) {
       // Other data processing instructions
       if ((instr->Opc2Field() == 0x7) && (instr->Opc3Field() == 0x3)) {
         DecodeVCVTBetweenDoubleAndSingle(instr);
       } else if ((instr->Opc2Field() == 0x8) && (instr->Opc3Field() & 0x1)) {
         DecodeVCVTBetweenFloatingPointAndInteger(instr);
       } else if (((instr->Opc2Field() >> 1) == 0x6) &&
                  (instr->Opc3Field() & 0x1)) {
         DecodeVCVTBetweenFloatingPointAndInteger(instr);
       } else if (((instr->Opc2Field() == 0x4) || (instr->Opc2Field() == 0x5)) &&
                  (instr->Opc3Field() & 0x1)) {
         DecodeVCMP(instr);
+      } else if (((instr->Opc2Field() == 0x1)) && (instr->Opc3Field() == 0x3)) {
+        // vsqrt
+        double dm_value = get_double_from_d_register(vm);
+        double dd_value = sqrt(dm_value);
+        set_d_register_from_double(vd, dd_value);
       } else {
         UNREACHABLE();  // Not used by V8.
       }
     } else if (instr->Opc1Field() == 0x3) {
       if (instr->SzField() != 0x1) {
         UNREACHABLE();  // Not used by V8.
       }
 
       if (instr->Opc3Field() & 0x1) {
         // vsub
@@ skipping 465 matching lines @@
   uintptr_t address = *stack_slot;
   set_register(sp, current_sp + sizeof(uintptr_t));
   return address;
 }
 
 } }  // namespace assembler::arm
 
 #endif  // __arm__
 
 #endif  // V8_TARGET_ARCH_ARM