Re: [Qemu-devel] [Qemu-arm] [PATCH v1 06/12] target/arm: Decode aa32 armv8.1 three same

["Alex Bennée" <alex.bennee@linaro.org>]

Richard Henderson <richard.henderson@linaro.org> writes:

> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/arm/translate.c | 83 ++++++++++++++++++++++++++++++++++++++------------
>  1 file changed, 64 insertions(+), 19 deletions(-)
>
> diff --git a/target/arm/translate.c b/target/arm/translate.c
> index ab1a12a1b8..0cd58710b3 100644
> --- a/target/arm/translate.c
> +++ b/target/arm/translate.c
> @@ -25,6 +25,7 @@
>  #include "disas/disas.h"
>  #include "exec/exec-all.h"
>  #include "tcg-op.h"
> +#include "tcg-op-gvec.h"
>  #include "qemu/log.h"
>  #include "qemu/bitops.h"
>  #include "arm_ldst.h"
> @@ -5334,9 +5335,9 @@ static void gen_neon_narrow_op(int op, int u, int size,
>  #define NEON_3R_VPMAX 20
>  #define NEON_3R_VPMIN 21
>  #define NEON_3R_VQDMULH_VQRDMULH 22
> -#define NEON_3R_VPADD 23
> +#define NEON_3R_VPADD_VQRDMLAH 23
>  #define NEON_3R_SHA 24 /* SHA1C,SHA1P,SHA1M,SHA1SU0,SHA256H{2},SHA256SU1 */
> -#define NEON_3R_VFM 25 /* VFMA, VFMS : float fused multiply-add */
> +#define NEON_3R_VFM_VQRDMLSH 25 /* VFMA, VFMS : float fused multiply-add */
>  #define NEON_3R_FLOAT_ARITH 26 /* float VADD, VSUB, VPADD, VABD */
>  #define NEON_3R_FLOAT_MULTIPLY 27 /* float VMLA, VMLS, VMUL */
>  #define NEON_3R_FLOAT_CMP 28 /* float VCEQ, VCGE, VCGT */
> @@ -5368,9 +5369,9 @@ static const uint8_t neon_3r_sizes[] = {
>      [NEON_3R_VPMAX] = 0x7,
>      [NEON_3R_VPMIN] = 0x7,
>      [NEON_3R_VQDMULH_VQRDMULH] = 0x6,
> -    [NEON_3R_VPADD] = 0x7,
> +    [NEON_3R_VPADD_VQRDMLAH] = 0x7,
>      [NEON_3R_SHA] = 0xf, /* size field encodes op type */
> -    [NEON_3R_VFM] = 0x5, /* size bit 1 encodes op */
> +    [NEON_3R_VFM_VQRDMLSH] = 0x7, /* For VFM, size bit 1 encodes op */
>      [NEON_3R_FLOAT_ARITH] = 0x5, /* size bit 1 encodes op */
>      [NEON_3R_FLOAT_MULTIPLY] = 0x5, /* size bit 1 encodes op */
>      [NEON_3R_FLOAT_CMP] = 0x5, /* size bit 1 encodes op */
> @@ -5556,6 +5557,7 @@ static const uint8_t neon_2rm_sizes[] = {
>
>  static int disas_neon_data_insn(DisasContext *s, uint32_t insn)
>  {
> +    void (*fn_gvec_ptr)(TCGv_ptr, TCGv_ptr, TCGv_ptr, TCGv_ptr, TCGv_i32);
>      int op;
>      int q;
>      int rd, rn, rm;
> @@ -5600,12 +5602,12 @@ static int disas_neon_data_insn(DisasContext *s, uint32_t insn)
>          if (q && ((rd | rn | rm) & 1)) {
>              return 1;
>          }
> -        /*
> -         * The SHA-1/SHA-256 3-register instructions require special treatment
> -         * here, as their size field is overloaded as an op type selector, and
> -         * they all consume their input in a single pass.
> -         */
> -        if (op == NEON_3R_SHA) {
> +        switch (op) {
> +        case NEON_3R_SHA:
> +            /* The SHA-1/SHA-256 3-register instructions require special
> +             * treatment here, as their size field is overloaded as an
> +             * op type selector, and they all consume their input in a
> +             * single pass.  */
>              if (!q) {
>                  return 1;
>              }
> @@ -5642,6 +5644,53 @@ static int disas_neon_data_insn(DisasContext *s, uint32_t insn)
>              tcg_temp_free_i32(tmp2);
>              tcg_temp_free_i32(tmp3);
>              return 0;
> +
> +        case NEON_3R_VPADD_VQRDMLAH:
> +            if (!u) {
> +                break;  /* VPADD */
> +            }
> +            /* VQRDMLAH */
> +            switch (size) {
> +            case 1:
> +                fn_gvec_ptr = gen_helper_gvec_qrdmlah_s16;
> +                break;
> +            case 2:
> +                fn_gvec_ptr = gen_helper_gvec_qrdmlah_s32;
> +                break;
> +            default:
> +                return 1;
> +            }
> +        do_vqrdmlx:
> +            if (arm_dc_feature(s, ARM_FEATURE_V8_1_SIMD)) {
> +                int opr_sz = (1 + q) * 8;
> +                tcg_gen_gvec_3_ptr(vfp_reg_offset(1, rd),
> +                                   vfp_reg_offset(1, rn),
> +                                   vfp_reg_offset(1, rm), cpu_env,
> +                                   opr_sz, opr_sz, 0, fn_gvec_ptr);
> +                return 0;
> +            }
> +            return 1;
> +
> +        case NEON_3R_VFM_VQRDMLSH:
> +            if (!u) {
> +                /* VFM, VFMS */
> +                if ((5 & (1 << size)) == 0) {
> +                    return 1;
> +                }
> +                break;
> +            }
> +            /* VQRDMLSH */
> +            switch (size) {
> +            case 1:
> +                fn_gvec_ptr = gen_helper_gvec_qrdmlsh_s16;
> +                break;
> +            case 2:
> +                fn_gvec_ptr = gen_helper_gvec_qrdmlsh_s32;
> +                break;
> +            default:
> +                return 1;
> +            }
> +            goto do_vqrdmlx;

Could we not take the opportunity to re-factor out the common bit rather
than make this mega function even more byzantine?

>          }
>          if (size == 3 && op != NEON_3R_LOGIC) {
>              /* 64-bit element instructions. */
> @@ -5727,11 +5776,7 @@ static int disas_neon_data_insn(DisasContext *s, uint32_t insn)
>                  rm = rtmp;
>              }
>              break;
> -        case NEON_3R_VPADD:
> -            if (u) {
> -                return 1;
> -            }
> -            /* Fall through */
> +        case NEON_3R_VPADD_VQRDMLAH:
>          case NEON_3R_VPMAX:
>          case NEON_3R_VPMIN:
>              pairwise = 1;
> @@ -5765,8 +5810,8 @@ static int disas_neon_data_insn(DisasContext *s, uint32_t insn)
>                  return 1;
>              }
>              break;
> -        case NEON_3R_VFM:
> -            if (!arm_dc_feature(s, ARM_FEATURE_VFP4) || u) {
> +        case NEON_3R_VFM_VQRDMLSH:
> +            if (!arm_dc_feature(s, ARM_FEATURE_VFP4)) {
>                  return 1;
>              }
>              break;
> @@ -5963,7 +6008,7 @@ static int disas_neon_data_insn(DisasContext *s, uint32_t insn)
>                  }
>              }
>              break;
> -        case NEON_3R_VPADD:
> +        case NEON_3R_VPADD_VQRDMLAH:
>              switch (size) {
>              case 0: gen_helper_neon_padd_u8(tmp, tmp, tmp2); break;
>              case 1: gen_helper_neon_padd_u16(tmp, tmp, tmp2); break;
> @@ -6062,7 +6107,7 @@ static int disas_neon_data_insn(DisasContext *s, uint32_t insn)
>                }
>              }
>              break;
> -        case NEON_3R_VFM:
> +        case NEON_3R_VFM_VQRDMLSH:
>          {
>              /* VFMA, VFMS: fused multiply-add */
>              TCGv_ptr fpstatus = get_fpstatus_ptr(1);


--
Alex Bennée