Re: [Qemu-devel] [PATCH v11 01/20] tcg: Allow multiple word entries into the constant pool

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

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

> This will be required for storing vector constants.
>
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

> ---
>  tcg/tcg-pool.inc.c | 115 +++++++++++++++++++++++++++++++++++++++++++----------
>  1 file changed, 93 insertions(+), 22 deletions(-)
>
> diff --git a/tcg/tcg-pool.inc.c b/tcg/tcg-pool.inc.c
> index 8a85131405..ecf7c9282b 100644
> --- a/tcg/tcg-pool.inc.c
> +++ b/tcg/tcg-pool.inc.c
> @@ -22,39 +22,110 @@
>
>  typedef struct TCGLabelPoolData {
>      struct TCGLabelPoolData *next;
> -    tcg_target_ulong data;
>      tcg_insn_unit *label;
> -    intptr_t addend;
> -    int type;
> +    int32_t addend;
> +    uint16_t rtype;
> +    uint16_t nlong;
> +    tcg_target_ulong data[];
>  } TCGLabelPoolData;
>
>
> -static void new_pool_label(TCGContext *s, tcg_target_ulong data, int type,
> -                           tcg_insn_unit *label, intptr_t addend)
> +static TCGLabelPoolData *new_pool_alloc(TCGContext *s, int nlong, int rtype,
> +                                        tcg_insn_unit *label, int addend)
>  {
> -    TCGLabelPoolData *n = tcg_malloc(sizeof(*n));
> -    TCGLabelPoolData *i, **pp;
> +    TCGLabelPoolData *n = tcg_malloc(sizeof(TCGLabelPoolData)
> +                                     + sizeof(tcg_target_ulong) * nlong);
>
> -    n->data = data;
>      n->label = label;
> -    n->type = type;
>      n->addend = addend;
> +    n->rtype = rtype;
> +    n->nlong = nlong;
> +    return n;
> +}
> +
> +static void new_pool_insert(TCGContext *s, TCGLabelPoolData *n)
> +{
> +    TCGLabelPoolData *i, **pp;
> +    int nlong = n->nlong;
>
>      /* Insertion sort on the pool.  */
> -    for (pp = &s->pool_labels; (i = *pp) && i->data < data; pp = &i->next) {
> -        continue;
> +    for (pp = &s->pool_labels; (i = *pp) != NULL; pp = &i->next) {
> +        if (nlong > i->nlong) {
> +            break;
> +        }
> +        if (nlong < i->nlong) {
> +            continue;
> +        }
> +        if (memcmp(n->data, i->data, sizeof(tcg_target_ulong) * nlong) >= 0) {
> +            break;
> +        }
>      }
>      n->next = *pp;
>      *pp = n;
>  }
>
> +/* The "usual" for generic integer code.  */
> +static inline void new_pool_label(TCGContext *s, tcg_target_ulong d, int rtype,
> +                                  tcg_insn_unit *label, int addend)
> +{
> +    TCGLabelPoolData *n = new_pool_alloc(s, 1, rtype, label, addend);
> +    n->data[0] = d;
> +    new_pool_insert(s, n);
> +}
> +
> +/* For v64 or v128, depending on the host.  */
> +static inline void new_pool_l2(TCGContext *s, int rtype, tcg_insn_unit *label,
> +                               int addend, tcg_target_ulong d0,
> +                               tcg_target_ulong d1)
> +{
> +    TCGLabelPoolData *n = new_pool_alloc(s, 2, rtype, label, addend);
> +    n->data[0] = d0;
> +    n->data[1] = d1;
> +    new_pool_insert(s, n);
> +}
> +
> +/* For v128 or v256, depending on the host.  */
> +static inline void new_pool_l4(TCGContext *s, int rtype, tcg_insn_unit *label,
> +                               int addend, tcg_target_ulong d0,
> +                               tcg_target_ulong d1, tcg_target_ulong d2,
> +                               tcg_target_ulong d3)
> +{
> +    TCGLabelPoolData *n = new_pool_alloc(s, 4, rtype, label, addend);
> +    n->data[0] = d0;
> +    n->data[1] = d1;
> +    n->data[2] = d2;
> +    n->data[3] = d3;
> +    new_pool_insert(s, n);
> +}
> +
> +/* For v256, for 32-bit host.  */
> +static inline void new_pool_l8(TCGContext *s, int rtype, tcg_insn_unit *label,
> +                               int addend, tcg_target_ulong d0,
> +                               tcg_target_ulong d1, tcg_target_ulong d2,
> +                               tcg_target_ulong d3, tcg_target_ulong d4,
> +                               tcg_target_ulong d5, tcg_target_ulong d6,
> +                               tcg_target_ulong d7)
> +{
> +    TCGLabelPoolData *n = new_pool_alloc(s, 8, rtype, label, addend);
> +    n->data[0] = d0;
> +    n->data[1] = d1;
> +    n->data[2] = d2;
> +    n->data[3] = d3;
> +    n->data[4] = d4;
> +    n->data[5] = d5;
> +    n->data[6] = d6;
> +    n->data[7] = d7;
> +    new_pool_insert(s, n);
> +}
> +
>  /* To be provided by cpu/tcg-target.inc.c.  */
>  static void tcg_out_nop_fill(tcg_insn_unit *p, int count);
>
>  static bool tcg_out_pool_finalize(TCGContext *s)
>  {
>      TCGLabelPoolData *p = s->pool_labels;
> -    tcg_target_ulong d, *a;
> +    TCGLabelPoolData *l = NULL;
> +    void *a;
>
>      if (p == NULL) {
>          return true;
> @@ -62,24 +133,24 @@ static bool tcg_out_pool_finalize(TCGContext *s)
>
>      /* ??? Round up to qemu_icache_linesize, but then do not round
>         again when allocating the next TranslationBlock structure.  */
> -    a = (void *)ROUND_UP((uintptr_t)s->code_ptr, sizeof(tcg_target_ulong));
> +    a = (void *)ROUND_UP((uintptr_t)s->code_ptr,
> +                         sizeof(tcg_target_ulong) * p->nlong);
>      tcg_out_nop_fill(s->code_ptr, (tcg_insn_unit *)a - s->code_ptr);
>      s->data_gen_ptr = a;
>
> -    /* Ensure the first comparison fails.  */
> -    d = p->data + 1;
> -
>      for (; p != NULL; p = p->next) {
> -        if (p->data != d) {
> -            d = p->data;
> -            if (unlikely((void *)a > s->code_gen_highwater)) {
> +        size_t size = sizeof(tcg_target_ulong) * p->nlong;
> +        if (!l || l->nlong != p->nlong || memcmp(l->data, p->data, size)) {
> +            if (unlikely(a > s->code_gen_highwater)) {
>                  return false;
>              }
> -            *a++ = d;
> +            memcpy(a, p->data, size);
> +            a += size;
> +            l = p;
>          }
> -        patch_reloc(p->label, p->type, (intptr_t)(a - 1), p->addend);
> +        patch_reloc(p->label, p->rtype, (intptr_t)a - size, p->addend);
>      }
>
> -    s->code_ptr = (void *)a;
> +    s->code_ptr = a;
>      return true;
>  }


--
Alex Bennée