1.1 --- a/src/cpu/x86/vm/x86_32.ad Wed May 04 03:42:58 2011 -0700
1.2 +++ b/src/cpu/x86/vm/x86_32.ad Wed May 04 13:12:42 2011 -0700
1.3 @@ -12989,6 +12989,53 @@
1.4 %}
1.5
1.6 // ============================================================================
1.7 +// Counted Loop limit node which represents exact final iterator value.
1.8 +// Note: the resulting value should fit into integer range since
1.9 +// counted loops have limit check on overflow.
1.10 +instruct loopLimit_eReg(eAXRegI limit, nadxRegI init, immI stride, eDXRegI limit_hi, nadxRegI tmp, eFlagsReg flags) %{
1.11 + match(Set limit (LoopLimit (Binary init limit) stride));
1.12 + effect(TEMP limit_hi, TEMP tmp, KILL flags);
1.13 + ins_cost(300);
1.14 +
1.15 + format %{ "loopLimit $init,$limit,$stride # $limit = $init + $stride *( $limit - $init + $stride -1)/ $stride, kills $limit_hi" %}
1.16 + ins_encode %{
1.17 + int strd = (int)$stride$$constant;
1.18 + assert(strd != 1 && strd != -1, "sanity");
1.19 + int m1 = (strd > 0) ? 1 : -1;
1.20 + // Convert limit to long (EAX:EDX)
1.21 + __ cdql();
1.22 + // Convert init to long (init:tmp)
1.23 + __ movl($tmp$$Register, $init$$Register);
1.24 + __ sarl($tmp$$Register, 31);
1.25 + // $limit - $init
1.26 + __ subl($limit$$Register, $init$$Register);
1.27 + __ sbbl($limit_hi$$Register, $tmp$$Register);
1.28 + // + ($stride - 1)
1.29 + if (strd > 0) {
1.30 + __ addl($limit$$Register, (strd - 1));
1.31 + __ adcl($limit_hi$$Register, 0);
1.32 + __ movl($tmp$$Register, strd);
1.33 + } else {
1.34 + __ addl($limit$$Register, (strd + 1));
1.35 + __ adcl($limit_hi$$Register, -1);
1.36 + __ lneg($limit_hi$$Register, $limit$$Register);
1.37 + __ movl($tmp$$Register, -strd);
1.38 + }
1.39 + // signed devision: (EAX:EDX) / pos_stride
1.40 + __ idivl($tmp$$Register);
1.41 + if (strd < 0) {
1.42 + // restore sign
1.43 + __ negl($tmp$$Register);
1.44 + }
1.45 + // (EAX) * stride
1.46 + __ mull($tmp$$Register);
1.47 + // + init (ignore upper bits)
1.48 + __ addl($limit$$Register, $init$$Register);
1.49 + %}
1.50 + ins_pipe( pipe_slow );
1.51 +%}
1.52 +
1.53 +// ============================================================================
1.54 // Branch Instructions
1.55 // Jump Table
1.56 instruct jumpXtnd(eRegI switch_val) %{
