target-m68k: Optimize gen_flush_flags

Backports commit 36f0399d46f2ccf4f6e7451ba46b1e8d0e9ab341 from qemu
This commit is contained in:
Richard Henderson 2018-02-27 10:19:49 -05:00 committed by Lioncash
parent 7403e63f2f
commit 4168095fed
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GPG Key ID: 4E3C3CC1031BA9C7

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@ -434,18 +434,66 @@ static TCGv gen_lea_indexed(CPUM68KState *env, DisasContext *s, TCGv base)
static void gen_flush_flags(DisasContext *s)
{
TCGContext *tcg_ctx = s->uc->tcg_ctx;
TCGv tmp;
TCGv t0, t1;
switch (s->cc_op) {
case CC_OP_FLAGS:
return;
case CC_OP_ADD:
tcg_gen_mov_i32(tcg_ctx, tcg_ctx->QREG_CC_C, tcg_ctx->QREG_CC_X);
tcg_gen_mov_i32(tcg_ctx, tcg_ctx->QREG_CC_Z, tcg_ctx->QREG_CC_N);
/* Compute signed overflow for addition. */
t0 = tcg_temp_new(tcg_ctx);
t1 = tcg_temp_new(tcg_ctx);
tcg_gen_sub_i32(tcg_ctx, t0, tcg_ctx->QREG_CC_N, tcg_ctx->QREG_CC_V);
tcg_gen_xor_i32(tcg_ctx, t1, tcg_ctx->QREG_CC_N, tcg_ctx->QREG_CC_V);
tcg_gen_xor_i32(tcg_ctx, tcg_ctx->QREG_CC_V, tcg_ctx->QREG_CC_V, t0);
tcg_temp_free(tcg_ctx, t0);
tcg_gen_andc_i32(tcg_ctx, tcg_ctx->QREG_CC_V, t1, tcg_ctx->QREG_CC_V);
tcg_temp_free(tcg_ctx, t1);
break;
case CC_OP_SUB:
tcg_gen_mov_i32(tcg_ctx, tcg_ctx->QREG_CC_C, tcg_ctx->QREG_CC_X);
tcg_gen_mov_i32(tcg_ctx, tcg_ctx->QREG_CC_Z, tcg_ctx->QREG_CC_N);
/* Compute signed overflow for subtraction. */
t0 = tcg_temp_new(tcg_ctx);
t1 = tcg_temp_new(tcg_ctx);
tcg_gen_add_i32(tcg_ctx, t0, tcg_ctx->QREG_CC_N, tcg_ctx->QREG_CC_V);
tcg_gen_xor_i32(tcg_ctx, t1, tcg_ctx->QREG_CC_N, tcg_ctx->QREG_CC_V);
tcg_gen_xor_i32(tcg_ctx, tcg_ctx->QREG_CC_V, tcg_ctx->QREG_CC_V, t0);
tcg_temp_free(tcg_ctx, t0);
tcg_gen_and_i32(tcg_ctx, tcg_ctx->QREG_CC_V, tcg_ctx->QREG_CC_V, t1);
tcg_temp_free(tcg_ctx, t1);
break;
case CC_OP_CMP:
tcg_gen_setcond_i32(tcg_ctx, TCG_COND_LTU, tcg_ctx->QREG_CC_C, tcg_ctx->QREG_CC_N, tcg_ctx->QREG_CC_V);
tcg_gen_sub_i32(tcg_ctx, tcg_ctx->QREG_CC_Z, tcg_ctx->QREG_CC_N, tcg_ctx->QREG_CC_V);
/* Compute signed overflow for subtraction. */
t0 = tcg_temp_new(tcg_ctx);
tcg_gen_xor_i32(tcg_ctx, t0, tcg_ctx->QREG_CC_Z, tcg_ctx->QREG_CC_N);
tcg_gen_xor_i32(tcg_ctx, tcg_ctx->QREG_CC_V, tcg_ctx->QREG_CC_V, tcg_ctx->QREG_CC_N);
tcg_gen_and_i32(tcg_ctx, tcg_ctx->QREG_CC_V, tcg_ctx->QREG_CC_V, t0);
tcg_temp_free(tcg_ctx, t0);
tcg_gen_mov_i32(tcg_ctx, tcg_ctx->QREG_CC_N, tcg_ctx->QREG_CC_Z);
break;
case CC_OP_LOGIC:
tcg_gen_mov_i32(tcg_ctx, tcg_ctx->QREG_CC_Z, tcg_ctx->QREG_CC_N);
tcg_gen_movi_i32(tcg_ctx, tcg_ctx->QREG_CC_C, 0);
tcg_gen_movi_i32(tcg_ctx, tcg_ctx->QREG_CC_V, 0);
break;
case CC_OP_DYNAMIC:
gen_helper_flush_flags(tcg_ctx, tcg_ctx->cpu_env, tcg_ctx->QREG_CC_OP);
break;
default:
tmp = tcg_const_i32(tcg_ctx, s->cc_op);
gen_helper_flush_flags(tcg_ctx, tcg_ctx->cpu_env, tmp);
tcg_temp_free(tcg_ctx, tmp);
t0 = tcg_const_i32(tcg_ctx, s->cc_op);
gen_helper_flush_flags(tcg_ctx, tcg_ctx->cpu_env, t0);
tcg_temp_free(tcg_ctx, t0);
break;
}