src/cpu/x86/vm/x86_64.ad

rev 3227 : 7133857: exp() and pow() should use the x87 ISA on x86
Summary: use x87 instructions to implement exp() and pow() in interpreter/c1/c2.
Reviewed-by:

*** 9840,9850 ****
--- 9840,9882 ----
                Opcode(0xD9), Opcode(0xF1),   // fyl2x
                Push_ResultXD(dst));
    ins_pipe( pipe_slow );
  %}
  
+ instruct powD_reg(regD dst, regD src0, regD src1, rax_RegI rax, rdx_RegI rdx, rcx_RegI rcx, rFlagsReg cr) %{
+   match(Set dst (PowD src0 src1));  // Raise src0 to the src1'th power
+   effect(KILL rax, KILL rdx, KILL rcx, KILL cr);
+   format %{ "fast_pow $src0 $src1 -> $dst  // KILL $rax, $rcx, $rdx" %}
+   ins_encode %{
+     __ subptr(rsp, 8);
+     __ movdbl(Address(rsp, 0), $src1$$XMMRegister);
+     __ fld_d(Address(rsp, 0));
+     __ movdbl(Address(rsp, 0), $src0$$XMMRegister);
+     __ fld_d(Address(rsp, 0));
+     __ fast_pow();
+     __ fstp_d(Address(rsp, 0));
+     __ movdbl($dst$$XMMRegister, Address(rsp, 0));
+     __ addptr(rsp, 8);
+   %}
+   ins_pipe( pipe_slow );
+ %}
  
+ instruct expD_reg(regD dst, regD src, rax_RegI rax, rdx_RegI rdx, rcx_RegI rcx, rFlagsReg cr) %{
+   match(Set dst (ExpD src));
+   effect(KILL rax, KILL rcx, KILL rdx, KILL cr);
+   format %{ "fast_exp $dst -> $src  // KILL $rax, $rcx, $rdx" %}
+   ins_encode %{
+     __ subptr(rsp, 8);
+     __ movdbl(Address(rsp, 0), $src$$XMMRegister);
+     __ fld_d(Address(rsp, 0));
+     __ fast_exp();
+     __ fstp_d(Address(rsp, 0));
+     __ movdbl($dst$$XMMRegister, Address(rsp, 0));
+     __ addptr(rsp, 8);
+   %}
+   ins_pipe( pipe_slow );
+ %}
  
  //----------Arithmetic Conversion Instructions---------------------------------
  
  instruct roundFloat_nop(regF dst)
  %{