On Tue, May 18, 2021 at 9:16 PM H.J. Lu <hjl.to...@gmail.com> wrote:
>
> Add TARGET_READ_MEMSET_VALUE and TARGET_GEN_MEMSET_VALUE to support
> target instructions to duplicate QImode value to TImode/OImode/XImode
> value for memmset.
>
> PR middle-end/90773
> * builtins.c (builtin_memset_read_str): Call
> targetm.read_memset_value.
> (builtin_memset_gen_str): Call targetm.gen_memset_value.
> * target.def (read_memset_value): New hook.
> (gen_memset_value): Likewise.
> * targhooks.c: Inclue "builtins.h".
> (default_read_memset_value): New function.
> (default_gen_memset_value): Likewise.
> * targhooks.h (default_read_memset_value): New prototype.
> (default_gen_memset_value): Likewise.
> * doc/tm.texi.in: Add TARGET_READ_MEMSET_VALUE and
> TARGET_GEN_MEMSET_VALUE hooks.
> * doc/tm.texi: Regenerated.
> ---
> gcc/builtins.c | 47 ++++----------------------------------
> gcc/doc/tm.texi | 16 +++++++++++++
> gcc/doc/tm.texi.in | 4 ++++
> gcc/target.def | 20 +++++++++++++++++
> gcc/targhooks.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++
> gcc/targhooks.h | 4 ++++
> 6 files changed, 104 insertions(+), 43 deletions(-)
>
> diff --git a/gcc/builtins.c b/gcc/builtins.c
> index e1b284846b1..f78a36478ef 100644
> --- a/gcc/builtins.c
> +++ b/gcc/builtins.c
> @@ -6584,24 +6584,11 @@ expand_builtin_strncpy (tree exp, rtx target)
> previous iteration. */
>
> rtx
> -builtin_memset_read_str (void *data, void *prevp,
> +builtin_memset_read_str (void *data, void *prev,
> HOST_WIDE_INT offset ATTRIBUTE_UNUSED,
> scalar_int_mode mode)
> {
> - by_pieces_prev *prev = (by_pieces_prev *) prevp;
> - if (prev != nullptr && prev->data != nullptr)
> - {
> - /* Use the previous data in the same mode. */
> - if (prev->mode == mode)
> - return prev->data;
> - }
> -
> - const char *c = (const char *) data;
> - char *p = XALLOCAVEC (char, GET_MODE_SIZE (mode));
> -
> - memset (p, *c, GET_MODE_SIZE (mode));
> -
> - return c_readstr (p, mode);
> + return targetm.read_memset_value ((const char *) data, prev, mode);
> }
>
> /* Callback routine for store_by_pieces. Return the RTL of a register
> @@ -6611,37 +6598,11 @@ builtin_memset_read_str (void *data, void *prevp,
> nullptr, it has the RTL info from the previous iteration. */
>
> static rtx
> -builtin_memset_gen_str (void *data, void *prevp,
> +builtin_memset_gen_str (void *data, void *prev,
> HOST_WIDE_INT offset ATTRIBUTE_UNUSED,
> scalar_int_mode mode)
> {
> - rtx target, coeff;
> - size_t size;
> - char *p;
> -
> - by_pieces_prev *prev = (by_pieces_prev *) prevp;
> - if (prev != nullptr && prev->data != nullptr)
> - {
> - /* Use the previous data in the same mode. */
> - if (prev->mode == mode)
> - return prev->data;
> -
> - target = simplify_gen_subreg (mode, prev->data, prev->mode, 0);
> - if (target != nullptr)
> - return target;
> - }
> -
> - size = GET_MODE_SIZE (mode);
> - if (size == 1)
> - return (rtx) data;
> -
> - p = XALLOCAVEC (char, size);
> - memset (p, 1, size);
> - coeff = c_readstr (p, mode);
> -
> - target = convert_to_mode (mode, (rtx) data, 1);
> - target = expand_mult (mode, target, coeff, NULL_RTX, 1);
> - return force_reg (mode, target);
> + return targetm.gen_memset_value ((rtx) data, prev, mode);
> }
>
> /* Expand expression EXP, which is a call to the memset builtin. Return
> diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
> index 85ea9395560..51385044e76 100644
> --- a/gcc/doc/tm.texi
> +++ b/gcc/doc/tm.texi
> @@ -11868,6 +11868,22 @@ This function prepares to emit a conditional
> comparison within a sequence
> @var{bit_code} is @code{AND} or @code{IOR}, which is the op on the compares.
> @end deftypefn
>
> +@deftypefn {Target Hook} rtx TARGET_READ_MEMSET_VALUE (const char *@var{c},
> void *@var{prev}, scalar_int_mode @var{mode})
> +This function returns the RTL of a constant integer corresponding to
> +target reading @code{GET_MODE_SIZE (@var{mode})} bytes from the stringn
> +constant @var{str}. If @var{prev} is not @samp{nullptr}, it contains
> +the RTL information from the previous interation.
> +@end deftypefn
> +
> +@deftypefn {Target Hook} rtx TARGET_GEN_MEMSET_VALUE (rtx @var{data}, void
> *@var{prev}, scalar_int_mode @var{mode})
> +This function returns the RTL of a register containing
> +@code{GET_MODE_SIZE (@var{mode})} consecutive copies of the unsigned
> +char value given in the RTL register @var{data}. For example, if
> +@var{mode} is 4 bytes wide, return the RTL for 0x01010101*@var{data}.
> +If @var{PREV} is not @samp{nullptr}, it is the RTL information from
> +the previous iteration.
> +@end deftypefn
> +
> @deftypefn {Target Hook} unsigned TARGET_LOOP_UNROLL_ADJUST (unsigned
> @var{nunroll}, class loop *@var{loop})
> This target hook returns a new value for the number of times @var{loop}
> should be unrolled. The parameter @var{nunroll} is the number of times
> diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
> index d8e3de14af1..8d4c3949fbf 100644
> --- a/gcc/doc/tm.texi.in
> +++ b/gcc/doc/tm.texi.in
> @@ -7956,6 +7956,10 @@ lists.
>
> @hook TARGET_GEN_CCMP_NEXT
>
> +@hook TARGET_READ_MEMSET_VALUE
> +
> +@hook TARGET_GEN_MEMSET_VALUE
> +
> @hook TARGET_LOOP_UNROLL_ADJUST
>
> @defmac POWI_MAX_MULTS
> diff --git a/gcc/target.def b/gcc/target.def
> index bbaf6b4f3a0..c9aca40fa88 100644
> --- a/gcc/target.def
> +++ b/gcc/target.def
> @@ -2694,6 +2694,26 @@ DEFHOOK
> rtx, (rtx_insn **prep_seq, rtx_insn **gen_seq, rtx prev, int cmp_code, tree
> op0, tree op1, int bit_code),
> NULL)
>
> +DEFHOOK
> +(read_memset_value,
> + "This function returns the RTL of a constant integer corresponding to\n\
> +target reading @code{GET_MODE_SIZE (@var{mode})} bytes from the stringn\n\
> +constant @var{str}. If @var{prev} is not @samp{nullptr}, it contains\n\
where is 'str' defined? I can't really tell what's the difference
from read_memset_value
and gen_memset_value.
Somehow I feel that an optab for the "splat" operation similar
to vec_duplicate might be a better way to expose this - of course
that doesn't handle the "prev" thing.
So how's this the right point of abstraction to the target?
> +the RTL information from the previous interation.",
> + rtx, (const char *c, void *prev, scalar_int_mode mode),
> + default_read_memset_value)
> +
> +DEFHOOK
> +(gen_memset_value,
> + "This function returns the RTL of a register containing\n\
> +@code{GET_MODE_SIZE (@var{mode})} consecutive copies of the unsigned\n\
> +char value given in the RTL register @var{data}. For example, if\n\
> +@var{mode} is 4 bytes wide, return the RTL for 0x01010101*@var{data}.\n\
> +If @var{PREV} is not @samp{nullptr}, it is the RTL information from\n\
> +the previous iteration.",
> + rtx, (rtx data, void *prev, scalar_int_mode mode),
> + default_gen_memset_value)
> +
> /* Return a new value for loop unroll size. */
> DEFHOOK
> (loop_unroll_adjust,
> diff --git a/gcc/targhooks.c b/gcc/targhooks.c
> index 1947ef26fd6..b55e6ec6756 100644
> --- a/gcc/targhooks.c
> +++ b/gcc/targhooks.c
> @@ -90,6 +90,7 @@ along with GCC; see the file COPYING3. If not see
> #include "attribs.h"
> #include "asan.h"
> #include "emit-rtl.h"
> +#include "builtins.h"
>
> bool
> default_legitimate_address_p (machine_mode mode ATTRIBUTE_UNUSED,
> @@ -2627,4 +2628,59 @@ default_memtag_untagged_pointer (rtx tagged_pointer,
> rtx target)
> return untagged_base;
> }
>
> +/* Default implementation of TARGET_READ_MEMSET_VALUE. */
> +
> +rtx
> +default_read_memset_value (const char *c, void *prevp,
> + scalar_int_mode mode)
> +{
> + by_pieces_prev *prev = (by_pieces_prev *) prevp;
> + if (prev != nullptr && prev->data != nullptr)
> + {
> + /* Use the previous data in the same mode. */
> + if (prev->mode == mode)
> + return prev->data;
> + }
> +
> + char *p = XALLOCAVEC (char, GET_MODE_SIZE (mode));
> +
> + memset (p, *c, GET_MODE_SIZE (mode));
> +
> + return c_readstr (p, mode);
> +}
> +
> +/* Default implementation of TARGET_GEN_MEMSET_VALUE. */
> +
> +rtx
> +default_gen_memset_value (rtx data, void *prevp, scalar_int_mode mode)
> +{
> + rtx target, coeff;
> + size_t size;
> + char *p;
> +
> + by_pieces_prev *prev = (by_pieces_prev *) prevp;
> + if (prev != nullptr && prev->data != nullptr)
> + {
> + /* Use the previous data in the same mode. */
> + if (prev->mode == mode)
> + return prev->data;
> +
> + target = simplify_gen_subreg (mode, prev->data, prev->mode, 0);
> + if (target != nullptr)
> + return target;
> + }
> +
> + size = GET_MODE_SIZE (mode);
> + if (size == 1)
> + return data;
> +
> + p = XALLOCAVEC (char, size);
> + memset (p, 1, size);
> + coeff = c_readstr (p, mode);
> +
> + target = convert_to_mode (mode, data, 1);
> + target = expand_mult (mode, target, coeff, NULL_RTX, 1);
> + return force_reg (mode, target);
> +}
> +
> #include "gt-targhooks.h"
> diff --git a/gcc/targhooks.h b/gcc/targhooks.h
> index b537038c0aa..3c00927e196 100644
> --- a/gcc/targhooks.h
> +++ b/gcc/targhooks.h
> @@ -300,4 +300,8 @@ extern rtx default_memtag_set_tag (rtx, rtx, rtx);
> extern rtx default_memtag_extract_tag (rtx, rtx);
> extern rtx default_memtag_untagged_pointer (rtx, rtx);
>
> +extern rtx default_read_memset_value (const char *, void *,
> + scalar_int_mode);
> +extern rtx default_gen_memset_value (rtx, void *, scalar_int_mode);
> +
> #endif /* GCC_TARGHOOKS_H */
> --
> 2.31.1
>
