RISC-V: Optimize reverse series index vector

Message ID 20230602063140.29401-1-juzhe.zhong@rivai.ai
State Committed
Commit 265357d401fb7215e8fea820d29a48eacdd75ad1
Headers
Series RISC-V: Optimize reverse series index vector |

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Commit Message

juzhe.zhong@rivai.ai June 2, 2023, 6:31 a.m. UTC
  From: Juzhe-Zhong <juzhe.zhong@rivai.ai>

This patch optimizes the following seriese vector:
[nunits - 1, nunits - 2, ...., 0]

Before this patch:
vid
vmul
vadd

After this patch:
vid
vrsub

This patch is an obvious and simple optimization, ok for trunk?

gcc/ChangeLog:

        * config/riscv/riscv-v.cc (expand_vec_series): Optimize reverse series index vector.

gcc/testsuite/ChangeLog:

        * gcc.target/riscv/rvv/autovec/vls-vlmax/perm-4.c: Add assembly check.

---
 gcc/config/riscv/riscv-v.cc                     | 17 +++++++++++++++++
 .../riscv/rvv/autovec/vls-vlmax/perm-4.c        |  2 ++
 2 files changed, 19 insertions(+)
  

Comments

Kito Cheng June 2, 2023, 6:59 a.m. UTC | #1
LGTM

On Fri, Jun 2, 2023 at 2:32 PM <juzhe.zhong@rivai.ai> wrote:
>
> From: Juzhe-Zhong <juzhe.zhong@rivai.ai>
>
> This patch optimizes the following seriese vector:
> [nunits - 1, nunits - 2, ...., 0]
>
> Before this patch:
> vid
> vmul
> vadd
>
> After this patch:
> vid
> vrsub
>
> This patch is an obvious and simple optimization, ok for trunk?
>
> gcc/ChangeLog:
>
>         * config/riscv/riscv-v.cc (expand_vec_series): Optimize reverse series index vector.
>
> gcc/testsuite/ChangeLog:
>
>         * gcc.target/riscv/rvv/autovec/vls-vlmax/perm-4.c: Add assembly check.
>
> ---
>  gcc/config/riscv/riscv-v.cc                     | 17 +++++++++++++++++
>  .../riscv/rvv/autovec/vls-vlmax/perm-4.c        |  2 ++
>  2 files changed, 19 insertions(+)
>
> diff --git a/gcc/config/riscv/riscv-v.cc b/gcc/config/riscv/riscv-v.cc
> index 1cd3bd3438e..75cf00b7eba 100644
> --- a/gcc/config/riscv/riscv-v.cc
> +++ b/gcc/config/riscv/riscv-v.cc
> @@ -530,6 +530,8 @@ expand_vec_series (rtx dest, rtx base, rtx step)
>    machine_mode mode = GET_MODE (dest);
>    machine_mode mask_mode;
>    gcc_assert (get_mask_mode (mode).exists (&mask_mode));
> +  poly_int64 nunits_m1 = GET_MODE_NUNITS (mode) - 1;
> +  poly_int64 value;
>
>    /* VECT_IV = BASE + I * STEP.  */
>
> @@ -545,6 +547,21 @@ expand_vec_series (rtx dest, rtx base, rtx step)
>    rtx step_adj;
>    if (rtx_equal_p (step, const1_rtx))
>      step_adj = vid;
> +  else if (rtx_equal_p (step, constm1_rtx) && poly_int_rtx_p (base, &value)
> +          && known_eq (nunits_m1, value))
> +    {
> +      /* Special case:
> +          {nunits - 1, nunits - 2, ... , 0}.
> +          nunits can be either const_int or const_poly_int.
> +
> +        Code sequence:
> +          vid.v v
> +          vrsub nunits - 1, v.  */
> +      rtx ops[] = {dest, vid, gen_int_mode (nunits_m1, GET_MODE_INNER (mode))};
> +      insn_code icode = code_for_pred_sub_reverse_scalar (mode);
> +      emit_vlmax_insn (icode, RVV_BINOP, ops);
> +      return;
> +    }
>    else
>      {
>        step_adj = gen_reg_rtx (mode);
> diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls-vlmax/perm-4.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls-vlmax/perm-4.c
> index 179c8274a92..aa328810c30 100644
> --- a/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls-vlmax/perm-4.c
> +++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls-vlmax/perm-4.c
> @@ -56,3 +56,5 @@
>  TEST_ALL (PERMUTE)
>
>  /* { dg-final { scan-assembler-times {vrgather\.vv\tv[0-9]+,\s*v[0-9]+,\s*v[0-9]+} 31 } } */
> +/* { dg-final { scan-assembler-times {vrsub\.vi} 24 } } */
> +/* { dg-final { scan-assembler-times {vrsub\.vx} 7 } } */
> --
> 2.36.1
>
  
Li, Pan2 via Gcc-patches June 2, 2023, 7:11 a.m. UTC | #2
Committed, thanks Kito.

Pan

-----Original Message-----
From: Gcc-patches <gcc-patches-bounces+pan2.li=intel.com@gcc.gnu.org> On Behalf Of Kito Cheng via Gcc-patches
Sent: Friday, June 2, 2023 3:00 PM
To: juzhe.zhong@rivai.ai
Cc: gcc-patches@gcc.gnu.org; kito.cheng@gmail.com; palmer@dabbelt.com; palmer@rivosinc.com; jeffreyalaw@gmail.com; rdapp.gcc@gmail.com
Subject: Re: [PATCH] RISC-V: Optimize reverse series index vector

LGTM

On Fri, Jun 2, 2023 at 2:32 PM <juzhe.zhong@rivai.ai> wrote:
>
> From: Juzhe-Zhong <juzhe.zhong@rivai.ai>
>
> This patch optimizes the following seriese vector:
> [nunits - 1, nunits - 2, ...., 0]
>
> Before this patch:
> vid
> vmul
> vadd
>
> After this patch:
> vid
> vrsub
>
> This patch is an obvious and simple optimization, ok for trunk?
>
> gcc/ChangeLog:
>
>         * config/riscv/riscv-v.cc (expand_vec_series): Optimize reverse series index vector.
>
> gcc/testsuite/ChangeLog:
>
>         * gcc.target/riscv/rvv/autovec/vls-vlmax/perm-4.c: Add assembly check.
>
> ---
>  gcc/config/riscv/riscv-v.cc                     | 17 +++++++++++++++++
>  .../riscv/rvv/autovec/vls-vlmax/perm-4.c        |  2 ++
>  2 files changed, 19 insertions(+)
>
> diff --git a/gcc/config/riscv/riscv-v.cc b/gcc/config/riscv/riscv-v.cc 
> index 1cd3bd3438e..75cf00b7eba 100644
> --- a/gcc/config/riscv/riscv-v.cc
> +++ b/gcc/config/riscv/riscv-v.cc
> @@ -530,6 +530,8 @@ expand_vec_series (rtx dest, rtx base, rtx step)
>    machine_mode mode = GET_MODE (dest);
>    machine_mode mask_mode;
>    gcc_assert (get_mask_mode (mode).exists (&mask_mode));
> +  poly_int64 nunits_m1 = GET_MODE_NUNITS (mode) - 1;
> +  poly_int64 value;
>
>    /* VECT_IV = BASE + I * STEP.  */
>
> @@ -545,6 +547,21 @@ expand_vec_series (rtx dest, rtx base, rtx step)
>    rtx step_adj;
>    if (rtx_equal_p (step, const1_rtx))
>      step_adj = vid;
> +  else if (rtx_equal_p (step, constm1_rtx) && poly_int_rtx_p (base, &value)
> +          && known_eq (nunits_m1, value))
> +    {
> +      /* Special case:
> +          {nunits - 1, nunits - 2, ... , 0}.
> +          nunits can be either const_int or const_poly_int.
> +
> +        Code sequence:
> +          vid.v v
> +          vrsub nunits - 1, v.  */
> +      rtx ops[] = {dest, vid, gen_int_mode (nunits_m1, GET_MODE_INNER (mode))};
> +      insn_code icode = code_for_pred_sub_reverse_scalar (mode);
> +      emit_vlmax_insn (icode, RVV_BINOP, ops);
> +      return;
> +    }
>    else
>      {
>        step_adj = gen_reg_rtx (mode);
> diff --git 
> a/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls-vlmax/perm-4.c 
> b/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls-vlmax/perm-4.c
> index 179c8274a92..aa328810c30 100644
> --- a/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls-vlmax/perm-4.c
> +++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls-vlmax/perm-4.c
> @@ -56,3 +56,5 @@
>  TEST_ALL (PERMUTE)
>
>  /* { dg-final { scan-assembler-times 
> {vrgather\.vv\tv[0-9]+,\s*v[0-9]+,\s*v[0-9]+} 31 } } */
> +/* { dg-final { scan-assembler-times {vrsub\.vi} 24 } } */
> +/* { dg-final { scan-assembler-times {vrsub\.vx} 7 } } */
> --
> 2.36.1
>
  

Patch

diff --git a/gcc/config/riscv/riscv-v.cc b/gcc/config/riscv/riscv-v.cc
index 1cd3bd3438e..75cf00b7eba 100644
--- a/gcc/config/riscv/riscv-v.cc
+++ b/gcc/config/riscv/riscv-v.cc
@@ -530,6 +530,8 @@  expand_vec_series (rtx dest, rtx base, rtx step)
   machine_mode mode = GET_MODE (dest);
   machine_mode mask_mode;
   gcc_assert (get_mask_mode (mode).exists (&mask_mode));
+  poly_int64 nunits_m1 = GET_MODE_NUNITS (mode) - 1;
+  poly_int64 value;
 
   /* VECT_IV = BASE + I * STEP.  */
 
@@ -545,6 +547,21 @@  expand_vec_series (rtx dest, rtx base, rtx step)
   rtx step_adj;
   if (rtx_equal_p (step, const1_rtx))
     step_adj = vid;
+  else if (rtx_equal_p (step, constm1_rtx) && poly_int_rtx_p (base, &value)
+	   && known_eq (nunits_m1, value))
+    {
+      /* Special case:
+	   {nunits - 1, nunits - 2, ... , 0}.
+	   nunits can be either const_int or const_poly_int.
+
+	 Code sequence:
+	   vid.v v
+	   vrsub nunits - 1, v.  */
+      rtx ops[] = {dest, vid, gen_int_mode (nunits_m1, GET_MODE_INNER (mode))};
+      insn_code icode = code_for_pred_sub_reverse_scalar (mode);
+      emit_vlmax_insn (icode, RVV_BINOP, ops);
+      return;
+    }
   else
     {
       step_adj = gen_reg_rtx (mode);
diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls-vlmax/perm-4.c b/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls-vlmax/perm-4.c
index 179c8274a92..aa328810c30 100644
--- a/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls-vlmax/perm-4.c
+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls-vlmax/perm-4.c
@@ -56,3 +56,5 @@ 
 TEST_ALL (PERMUTE)
 
 /* { dg-final { scan-assembler-times {vrgather\.vv\tv[0-9]+,\s*v[0-9]+,\s*v[0-9]+} 31 } } */
+/* { dg-final { scan-assembler-times {vrsub\.vi} 24 } } */
+/* { dg-final { scan-assembler-times {vrsub\.vx} 7 } } */