[PATCH] MATCH: Optimize COND_ADD_LEN reduction pattern
Richard Biener
richard.guenther@gmail.com
Tue Sep 26 07:46:04 GMT 2023
On Tue, Sep 26, 2023 at 9:13 AM Juzhe-Zhong <juzhe.zhong@rivai.ai> wrote:
>
>
> This patch leverage this commit: https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;h=62b505a4d5fc89
> to optimize COND_LEN_ADD reduction pattern.
>
> We are doing optimization of VEC_COND_EXPR + COND_LEN_ADD -> COND_LEN_ADD.
>
> Consider thsi following case:
>
> #include <stdint.h>
>
> void
> pr11594 (uint64_t *restrict a, uint64_t *restrict b, int loop_size)
> {
> uint64_t result = 0;
>
> for (int i = 0; i < loop_size; i++)
> {
> if (b[i] <= a[i])
> {
> result += a[i];
> }
> }
>
> a[0] = result;
> }
>
> Before this patch:
> vsetvli a7,zero,e64,m1,ta,ma
> vmv.v.i v2,0
> vmv1r.v v3,v2 --- redundant
> .L3:
> vsetvli a5,a2,e64,m1,ta,ma
> vle64.v v1,0(a3)
> vle64.v v0,0(a1)
> slli a6,a5,3
> vsetvli a7,zero,e64,m1,ta,ma
> sub a2,a2,a5
> vmsleu.vv v0,v0,v1
> add a1,a1,a6
> vmerge.vvm v1,v3,v1,v0 ---- redundant.
> add a3,a3,a6
> vsetvli zero,a5,e64,m1,tu,ma
> vadd.vv v2,v2,v1
> bne a2,zero,.L3
> li a5,0
> vsetvli a4,zero,e64,m1,ta,ma
> vmv.s.x v1,a5
> vredsum.vs v2,v2,v1
> vmv.x.s a5,v2
> sd a5,0(a0)
> ret
>
> After this patch:
>
> vsetvli a6,zero,e64,m1,ta,ma
> vmv.v.i v1,0
> .L3:
> vsetvli a5,a2,e64,m1,ta,ma
> vle64.v v2,0(a4)
> vle64.v v0,0(a1)
> slli a3,a5,3
> vsetvli a6,zero,e64,m1,ta,ma
> sub a2,a2,a5
> vmsleu.vv v0,v0,v2
> add a1,a1,a3
> vsetvli zero,a5,e64,m1,tu,mu
> add a4,a4,a3
> vadd.vv v1,v1,v2,v0.t
> bne a2,zero,.L3
> li a5,0
> vsetivli zero,1,e64,m1,ta,ma
> vmv.s.x v2,a5
> vsetvli a5,zero,e64,m1,ta,ma
> vredsum.vs v1,v1,v2
> vmv.x.s a5,v1
> sd a5,0(a0)
> ret
>
> Bootstrap && Regression is running.
>
> Ok for trunk when testing passes ?
>
> PR tree-optimization/111594
> PR tree-optimization/110660
>
> gcc/ChangeLog:
>
> * match.pd: Optimize COND_LEN_ADD reduction.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/riscv/rvv/autovec/cond/cond_reduc-1.c: New test.
> * gcc.target/riscv/rvv/autovec/cond/pr111594.c: New test.
>
> ---
> gcc/match.pd | 13 +++++++++
> .../riscv/rvv/autovec/cond/cond_reduc-1.c | 29 +++++++++++++++++++
> .../riscv/rvv/autovec/cond/pr111594.c | 22 ++++++++++++++
> 3 files changed, 64 insertions(+)
> create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/autovec/cond/cond_reduc-1.c
> create mode 100644 gcc/testsuite/gcc.target/riscv/rvv/autovec/cond/pr111594.c
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index a17778fbaa6..af8d12c138e 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -8866,6 +8866,19 @@ and,
> (IFN_COND_ADD @0 @1 (vec_cond @2 @3 integer_zerop) @1)
> (IFN_COND_ADD (bit_and @0 @2) @1 @3 @1))
>
> +/* Detect simplication for a conditional length reduction where
> +
> + a = mask ? b : 0
> + c = i < len + bias ? d + a : d
> +
> + is turned into
> +
> + c = mask && i < len ? d + b : d. */
> +(simplify
> + (IFN_COND_LEN_ADD integer_minus_onep @0 (vec_cond @1 @2 zerop) @0 @3 @4)
I think you want intger_truep instead of integer_minus_onep for
readability. Since you
use zerop here can you also adjust the preceeding pattern?
> + (if (!HONOR_NANS (type) && !HONOR_SIGNED_ZEROS (type))
it might be better to check ANY_INTEGRAL_TYPE_P (type) ||
fold_real_zero_addition_p (type, NULL_TREE, @5, 0)
your change misses HONOR_SIGN_DEPENDENT_ROUNDING I think.
> + (IFN_COND_LEN_ADD @1 @0 @2 @0 @3 @4)))
> +
> /* For pointers @0 and @2 and nonnegative constant offset @1, look for
> expressions like:
>
> diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/cond/cond_reduc-1.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/cond/cond_reduc-1.c
> new file mode 100644
> index 00000000000..db6f9d1ec6c
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/cond/cond_reduc-1.c
> @@ -0,0 +1,29 @@
> +/* { dg-do compile } */
> +/* { dg-additional-options "-march=rv64gcv_zvfh -mabi=lp64d -fno-vect-cost-model -ffast-math -fdump-tree-optimized" } */
> +
> +#include <stdint-gcc.h>
> +
> +#define COND_REDUCTION(TYPE) \
> + TYPE foo##TYPE (TYPE *restrict a, TYPE *restrict b, int loop_size) \
> + { \
> + TYPE result = 0; \
> + for (int i = 0; i < loop_size; i++) \
> + if (b[i] <= a[i]) \
> + result += a[i]; \
> + return result; \
> + }
> +
> +COND_REDUCTION (int8_t)
> +COND_REDUCTION (int16_t)
> +COND_REDUCTION (int32_t)
> +COND_REDUCTION (int64_t)
> +COND_REDUCTION (uint8_t)
> +COND_REDUCTION (uint16_t)
> +COND_REDUCTION (uint32_t)
> +COND_REDUCTION (uint64_t)
> +COND_REDUCTION (_Float16)
> +COND_REDUCTION (float)
> +COND_REDUCTION (double)
> +
> +/* { dg-final { scan-tree-dump-not "VCOND_MASK" "optimized" } } */
> +/* { dg-final { scan-tree-dump-times "COND_LEN_ADD" 11 "optimized" } } */
> diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/cond/pr111594.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/cond/pr111594.c
> new file mode 100644
> index 00000000000..6d81b26fbd0
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/cond/pr111594.c
> @@ -0,0 +1,22 @@
> +/* { dg-do compile } */
> +/* { dg-additional-options "-march=rv64gcv -mabi=lp64d -fno-vect-cost-model -ffast-math" } */
> +
> +#include <stdint-gcc.h>
> +
> +void
> +pr11594 (uint64_t *restrict a, uint64_t *restrict b, int loop_size)
> +{
> + uint64_t result = 0;
> +
> + for (int i = 0; i < loop_size; i++)
> + {
> + if (b[i] <= a[i])
> + {
> + result += a[i];
> + }
> + }
> +
> + a[0] = result;
> +}
> +
> +/* { dg-final { scan-assembler-not {vmerge} } } */
> --
> 2.36.3
>
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