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target/s390x: Improve general case of disas_jcc

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Avoid code duplication by handling 7 of the 14 cases
by inverting the test for the other 7 cases.

Use TCG_COND_TSTNE for cc in {1,3}.
Use (cc - 1) <= 1 for cc in {1,2}.

Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2023-11-06 15:07:58 -08:00
parent 7da3601e62
commit f9ec459da8
1 changed files with 30 additions and 52 deletions
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82
target/s390x/tcg/translate.c
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@ -885,67 +885,45 @@ static void disas_jcc(DisasContext *s, DisasCompare *c, uint32_t mask)
case CC_OP_STATIC:
c->is_64 = false;
c->u.s32.a = cc_op;
switch (mask) {
case 0x8 | 0x4 | 0x2: /* cc != 3 */
cond = TCG_COND_NE;
/* Fold half of the cases using bit 3 to invert. */
switch (mask & 8 ? mask ^ 0xf : mask) {
case 0x1: /* cc == 3 */
cond = TCG_COND_EQ;
c->u.s32.b = tcg_constant_i32(3);
break;
case 0x8 | 0x4 | 0x1: /* cc != 2 */
cond = TCG_COND_NE;
c->u.s32.b = tcg_constant_i32(2);
break;
case 0x8 | 0x2 | 0x1: /* cc != 1 */
cond = TCG_COND_NE;
c->u.s32.b = tcg_constant_i32(1);
break;
case 0x8 | 0x2: /* cc == 0 || cc == 2 => (cc & 1) == 0 */
cond = TCG_COND_EQ;
c->u.s32.a = tcg_temp_new_i32();
c->u.s32.b = tcg_constant_i32(0);
tcg_gen_andi_i32(c->u.s32.a, cc_op, 1);
break;
case 0x8 | 0x4: /* cc < 2 */
cond = TCG_COND_LTU;
c->u.s32.b = tcg_constant_i32(2);
break;
case 0x8: /* cc == 0 */
cond = TCG_COND_EQ;
c->u.s32.b = tcg_constant_i32(0);
break;
case 0x4 | 0x2 | 0x1: /* cc != 0 */
cond = TCG_COND_NE;
c->u.s32.b = tcg_constant_i32(0);
break;
case 0x4 | 0x1: /* cc == 1 || cc == 3 => (cc & 1) != 0 */
cond = TCG_COND_NE;
c->u.s32.a = tcg_temp_new_i32();
c->u.s32.b = tcg_constant_i32(0);
tcg_gen_andi_i32(c->u.s32.a, cc_op, 1);
break;
case 0x4: /* cc == 1 */
cond = TCG_COND_EQ;
c->u.s32.b = tcg_constant_i32(1);
break;
case 0x2 | 0x1: /* cc > 1 */
cond = TCG_COND_GTU;
c->u.s32.b = tcg_constant_i32(1);
break;
case 0x2: /* cc == 2 */
cond = TCG_COND_EQ;
c->u.s32.b = tcg_constant_i32(2);
break;
case 0x1: /* cc == 3 */
case 0x4: /* cc == 1 */
cond = TCG_COND_EQ;
c->u.s32.b = tcg_constant_i32(3);
c->u.s32.b = tcg_constant_i32(1);
break;
case 0x2 | 0x1: /* cc == 2 || cc == 3 => cc > 1 */
cond = TCG_COND_GTU;
c->u.s32.b = tcg_constant_i32(1);
break;
case 0x4 | 0x1: /* cc == 1 || cc == 3 => (cc & 1) != 0 */
cond = TCG_COND_TSTNE;
c->u.s32.b = tcg_constant_i32(1);
break;
case 0x4 | 0x2: /* cc == 1 || cc == 2 => (cc - 1) <= 1 */
cond = TCG_COND_LEU;
c->u.s32.a = tcg_temp_new_i32();
c->u.s32.b = tcg_constant_i32(1);
tcg_gen_addi_i32(c->u.s32.a, cc_op, -1);
break;
case 0x4 | 0x2 | 0x1: /* cc != 0 */
cond = TCG_COND_NE;
c->u.s32.b = tcg_constant_i32(0);
break;
default:
/* CC is masked by something else: (8 >> cc) & mask. */
cond = TCG_COND_NE;
c->u.s32.a = tcg_temp_new_i32();
c->u.s32.b = tcg_constant_i32(0);
tcg_gen_shr_i32(c->u.s32.a, tcg_constant_i32(8), cc_op);
tcg_gen_andi_i32(c->u.s32.a, c->u.s32.a, mask);
break;
/* case 0: never, handled above. */
g_assert_not_reached();
}
if (mask & 8) {
cond = tcg_invert_cond(cond);
}
break;