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CRIS: Slight performance improvement for flag evaluation.

Browse source 
Translate sub and cmp ops separately when evaluating flags to avoid checking
for them at runtime.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6198 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
edgar_igl 2009-01-07 12:25:15 +00:00
parent 10c144e2fb
commit a8cf66bb39
3 changed files with 79 additions and 62 deletions
Download patch file Download diff file Expand all files Collapse all files

26
target-cris/translate.c
View file

@ -728,8 +728,15 @@ static void cris_evaluate_flags(DisasContext *dc)
case CC_OP_FLAGS:
/* live. */
break;
case CC_OP_SUB:
case CC_OP_CMP:
if (dc->cc_size == 4)
gen_helper_evaluate_flags_sub_4();
else
gen_helper_evaluate_flags();
break;
default:
{
switch (dc->cc_size)
{
case 4:
@ -739,7 +746,6 @@ static void cris_evaluate_flags(DisasContext *dc)
gen_helper_evaluate_flags();
break;
}
}
break;
}
if (dc->flagx_known) {
@ -821,13 +827,8 @@ static void cris_pre_alu_update_cc(DisasContext *dc, int op,
/* Update cc after executing ALU op. needs the result. */
static inline void cris_update_result(DisasContext *dc, TCGv res)
{
if (dc->update_cc) {
if (dc->cc_size == 4 &&
(dc->cc_op == CC_OP_SUB
|| dc->cc_op == CC_OP_ADD))
return;
if (dc->update_cc)
tcg_gen_mov_tl(cc_result, res);
}
}
/* Returns one if the write back stage should execute. */
@ -1890,6 +1891,10 @@ static unsigned int dec_addc_r(DisasContext *dc)
DIS(fprintf (logfile, "addc $r%u, $r%u\n",
dc->op1, dc->op2));
cris_evaluate_flags(dc);
/* Set for this insn. */
dc->flagx_known = 1;
dc->flags_x = X_FLAG;
cris_cc_mask(dc, CC_MASK_NZVC);
cris_alu(dc, CC_OP_ADDC,
cpu_R[dc->op2], cpu_R[dc->op2], cpu_R[dc->op1], 4);
@ -2615,6 +2620,11 @@ static unsigned int dec_addc_mr(DisasContext *dc)
dc->op2));
cris_evaluate_flags(dc);
/* Set for this insn. */
dc->flagx_known = 1;
dc->flags_x = X_FLAG;
cris_alu_m_alloc_temps(t);
insn_len = dec_prep_alu_m(dc, 0, 4, t[0], t[1]);
cris_cc_mask(dc, CC_MASK_NZVC);