[x64] Implemennt vroundsd AVX instruction.

test/cctest/test-disasm-x64.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 522 matching lines @@
       __ vmulsd(xmm0, xmm1, xmm2);
       __ vmulsd(xmm0, xmm1, Operand(rbx, rcx, times_4, 10000));
       __ vsubsd(xmm0, xmm1, xmm2);
       __ vsubsd(xmm0, xmm1, Operand(rbx, rcx, times_4, 10000));
       __ vdivsd(xmm0, xmm1, xmm2);
       __ vdivsd(xmm0, xmm1, Operand(rbx, rcx, times_2, 10000));
       __ vminsd(xmm8, xmm1, xmm2);
       __ vminsd(xmm9, xmm1, Operand(rbx, rcx, times_8, 10000));
       __ vmaxsd(xmm8, xmm1, xmm2);
       __ vmaxsd(xmm9, xmm1, Operand(rbx, rcx, times_1, 10000));
+      __ vroundsd(xmm8, xmm3, xmm0, kRoundDown);
       __ vsqrtsd(xmm8, xmm1, xmm2);
       __ vsqrtsd(xmm9, xmm1, Operand(rbx, rcx, times_1, 10000));
       __ vucomisd(xmm9, xmm1);
       __ vucomisd(xmm8, Operand(rbx, rdx, times_2, 10981));
 
       __ vcvtss2sd(xmm4, xmm9, xmm11);
       __ vcvtsd2ss(xmm9, xmm3, xmm2);
       __ vcvtss2sd(xmm4, xmm9, Operand(rbx, rcx, times_1, 10000));
       __ vcvtsd2ss(xmm9, xmm3, Operand(rbx, rcx, times_1, 10000));
       __ vcvtlsi2sd(xmm5, xmm9, rcx);
@@ skipping 210 matching lines @@
 #ifdef OBJECT_PRINT
   OFStream os(stdout);
   code->Print(os);
   byte* begin = code->instruction_start();
   byte* end = begin + code->instruction_size();
   disasm::Disassembler::Disassemble(stdout, begin, end);
 #endif
 }
 
 #undef __