On Thu, 14 Dec 2023, Juzhe-Zhong wrote:
> Follow Richard's suggestions, we should not model address cost in the loop
> vectorizer for select_vl or decrement IV since other style vectorization
> doesn't
> do that.
>
> To make cost model comparison apple to apple.
> This patch set COST from 2 to 1 which turns out have better codegen
> in various codegen for RVV.
>
> Ok for trunk ?
OK with me.
Richard.
> PR target/111153
>
> gcc/ChangeLog:
>
> * tree-vect-loop.cc (vect_estimate_min_profitable_iters): Remove
> address cost for select_vl/decrement IV.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/vect/costmodel/riscv/rvv/pr111153.c: Moved to...
> * gcc.dg/vect/costmodel/riscv/rvv/pr11153-2.c: ...here.
> * gcc.dg/vect/costmodel/riscv/rvv/pr111153-1.c: New test.
>
> ---
> .../vect/costmodel/riscv/rvv/pr111153-1.c | 18 ++++++++++++++++++
> .../riscv/rvv/{pr111153.c => pr11153-2.c} | 4 ++--
> gcc/tree-vect-loop.cc | 10 ++++------
> 3 files changed, 24 insertions(+), 8 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/pr111153-1.c
> rename gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/{pr111153.c =>
> pr11153-2.c} (93%)
>
> diff --git a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/pr111153-1.c
> b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/pr111153-1.c
> new file mode 100644
> index 00000000000..51c91f7410c
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/pr111153-1.c
> @@ -0,0 +1,18 @@
> +/* { dg-do compile } */
> +/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -ftree-vectorize
> -mtune=generic-ooo -ffast-math" } */
> +
> +#define DEF_REDUC_PLUS(TYPE)
> \
> + TYPE __attribute__ ((noinline, noclone))
> \
> + reduc_plus_##TYPE (TYPE *__restrict a, int n)
> \
> + {
> \
> + TYPE r = 0;
> \
> + for (int i = 0; i < n; ++i)
> \
> + r += a[i];
> \
> + return r;
> \
> + }
> +
> +#define TEST_PLUS(T) T (int) T (float)
> +
> +TEST_PLUS (DEF_REDUC_PLUS)
> +
> +/* { dg-final { scan-assembler-not {vsetivli\s+zero,\s*4} } } */
> diff --git a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/pr111153.c
> b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/pr11153-2.c
> similarity index 93%
> rename from gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/pr111153.c
> rename to gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/pr11153-2.c
> index 06e08ec5f2e..d361f1fc7fa 100644
> --- a/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/pr111153.c
> +++ b/gcc/testsuite/gcc.dg/vect/costmodel/riscv/rvv/pr11153-2.c
> @@ -1,5 +1,5 @@
> /* { dg-do compile } */
> -/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -ftree-vectorize
> -mtune=generic-ooo" } */
> +/* { dg-options "-march=rv64gcv -mabi=lp64d -O3 -ftree-vectorize
> -ffast-math" } */
>
> #define DEF_REDUC_PLUS(TYPE)
> \
> TYPE __attribute__ ((noinline, noclone))
> \
> @@ -11,7 +11,7 @@
> return r;
> \
> }
>
> -#define TEST_PLUS(T) T (int)
> +#define TEST_PLUS(T) T (int) T (float)
>
> TEST_PLUS (DEF_REDUC_PLUS)
>
> diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
> index 19e38b8637b..7a3db5f098b 100644
> --- a/gcc/tree-vect-loop.cc
> +++ b/gcc/tree-vect-loop.cc
> @@ -4872,12 +4872,10 @@ vect_estimate_min_profitable_iters (loop_vec_info
> loop_vinfo,
>
> unsigned int length_update_cost = 0;
> if (LOOP_VINFO_USING_DECREMENTING_IV_P (loop_vinfo))
> - /* For decrement IV style, we use a single SELECT_VL since
> - beginning to calculate the number of elements need to be
> - processed in current iteration, and a SHIFT operation to
> - compute the next memory address instead of adding vectorization
> - factor. */
> - length_update_cost = 2;
> + /* For decrement IV style, Each only need a single SELECT_VL
> + or MIN since beginning to calculate the number of elements
> + need to be processed in current iteration. */
> + length_update_cost = 1;
> else
> /* For increment IV stype, Each may need two MINs and one MINUS to
> update lengths in body for next iteration. */
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
