target/mips/mxu: Add Q8SLT Q8SLTU instructions

These instructions are used to set bits depending on
comparison result in each byte respectively.

Signed-off-by: Siarhei Volkau <lis8215@gmail.com>
Message-Id: <20230608104222.1520143-6-lis8215@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
This commit is contained in:
Siarhei Volkau 2023-06-08 13:41:54 +03:00 committed by Philippe Mathieu-Daudé
parent 199fc7d279
commit 4051f035e0
1 changed files with 65 additions and 0 deletions

View File

@ -387,6 +387,8 @@ enum {
OPC_MXU_D16MIN = 0x03,
OPC_MXU_Q8MAX = 0x04,
OPC_MXU_Q8MIN = 0x05,
OPC_MXU_Q8SLT = 0x06,
OPC_MXU_Q8SLTU = 0x07,
};
/*
@ -1397,6 +1399,63 @@ static void gen_mxu_Q8MAX_Q8MIN(DisasContext *ctx)
}
}
/*
* Q8SLT
* Update XRa with the signed "set less than" comparison of XRb and XRc
* on per-byte basis.
* a.k.a. XRa[0..3] = XRb[0..3] < XRc[0..3] ? 1 : 0;
*
* Q8SLTU
* Update XRa with the unsigned "set less than" comparison of XRb and XRc
* on per-byte basis.
* a.k.a. XRa[0..3] = XRb[0..3] < XRc[0..3] ? 1 : 0;
*/
static void gen_mxu_q8slt(DisasContext *ctx, bool sltu)
{
uint32_t pad, XRc, XRb, XRa;
pad = extract32(ctx->opcode, 21, 5);
XRc = extract32(ctx->opcode, 14, 4);
XRb = extract32(ctx->opcode, 10, 4);
XRa = extract32(ctx->opcode, 6, 4);
if (unlikely(pad != 0)) {
/* opcode padding incorrect -> do nothing */
} else if (unlikely(XRa == 0)) {
/* destination is zero register -> do nothing */
} else if (unlikely((XRb == 0) && (XRc == 0))) {
/* both operands zero registers -> just set destination to zero */
tcg_gen_movi_tl(mxu_gpr[XRa - 1], 0);
} else if (unlikely(XRb == XRc)) {
/* both operands same registers -> just set destination to zero */
tcg_gen_movi_tl(mxu_gpr[XRa - 1], 0);
} else {
/* the most general case */
TCGv t0 = tcg_temp_new();
TCGv t1 = tcg_temp_new();
TCGv t2 = tcg_temp_new();
TCGv t3 = tcg_temp_new();
TCGv t4 = tcg_temp_new();
gen_load_mxu_gpr(t3, XRb);
gen_load_mxu_gpr(t4, XRc);
tcg_gen_movi_tl(t2, 0);
for (int i = 0; i < 4; i++) {
if (sltu) {
tcg_gen_extract_tl(t0, t3, 8 * i, 8);
tcg_gen_extract_tl(t1, t4, 8 * i, 8);
} else {
tcg_gen_sextract_tl(t0, t3, 8 * i, 8);
tcg_gen_sextract_tl(t1, t4, 8 * i, 8);
}
tcg_gen_setcond_tl(TCG_COND_LT, t0, t0, t1);
tcg_gen_deposit_tl(t2, t2, t0, 8 * i, 8);
}
gen_store_mxu_gpr(t2, XRa);
}
}
/*
* MXU instruction category: align
@ -1662,6 +1721,12 @@ static void decode_opc_mxu__pool00(DisasContext *ctx)
case OPC_MXU_Q8MIN:
gen_mxu_Q8MAX_Q8MIN(ctx);
break;
case OPC_MXU_Q8SLT:
gen_mxu_q8slt(ctx, false);
break;
case OPC_MXU_Q8SLTU:
gen_mxu_q8slt(ctx, true);
break;
default:
MIPS_INVAL("decode_opc_mxu");
gen_reserved_instruction(ctx);