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target-mips: implement movn/movz using movcond 

Avoid the branches in movn/movz implementation and replace them with
movcond. Also update a wrong command.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This commit is contained in:
Aurelien Jarno 2012-10-09 21:53:21 +02:00
parent 2d2826b99e
commit acf1246558
1 changed files with 12 additions and 15 deletions
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27
target-mips/translate.c
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@ -2359,35 +2359,32 @@ static void gen_cond_move(CPUMIPSState *env, DisasContext *ctx, uint32_t opc,
int rd, int rs, int rt)
{
const char *opn = "cond move";
int l1;
TCGv t0, t1, t2;
if (rd == 0) {
/* If no destination, treat it as a NOP.
For add & sub, we must generate the overflow exception when needed. */
/* If no destination, treat it as a NOP. */
MIPS_DEBUG("NOP");
return;
}
l1 = gen_new_label();
t0 = tcg_temp_new();
gen_load_gpr(t0, rt);
t1 = tcg_const_tl(0);
t2 = tcg_temp_new();
gen_load_gpr(t2, rs);
switch (opc) {
case OPC_MOVN:
if (likely(rt != 0))
tcg_gen_brcondi_tl(TCG_COND_EQ, cpu_gpr[rt], 0, l1);
else
tcg_gen_br(l1);
tcg_gen_movcond_tl(TCG_COND_NE, cpu_gpr[rd], t0, t1, t2, cpu_gpr[rd]);
opn = "movn";
break;
case OPC_MOVZ:
if (likely(rt != 0))
tcg_gen_brcondi_tl(TCG_COND_NE, cpu_gpr[rt], 0, l1);
tcg_gen_movcond_tl(TCG_COND_EQ, cpu_gpr[rd], t0, t1, t2, cpu_gpr[rd]);
opn = "movz";
break;
}
if (rs != 0)
tcg_gen_mov_tl(cpu_gpr[rd], cpu_gpr[rs]);
else
tcg_gen_movi_tl(cpu_gpr[rd], 0);
gen_set_label(l1);
tcg_temp_free(t2);
tcg_temp_free(t1);
tcg_temp_free(t0);
(void)opn; /* avoid a compiler warning */
MIPS_DEBUG("%s %s, %s, %s", opn, regnames[rd], regnames[rs], regnames[rt]);