Committed, thanks Juzhe.
--------------
Li Xu
>LGTM. You can commit it after you pass the regression.
>
>
>
>juzhe.zh...@rivai.ai
>
>From: Li Xu
>Date: 2023-09-22 10:37
>To: gcc-patches
>CC: kito.cheng; palmer; juzhe.zhong; xuli
>Subject: [PATCH V2] RISC-V: Optimization of vrgather.vv into
>vrgatherei16.vv[PR111451]
>From: xuli <xu...@eswincomputing.com>
>
>Consider this following case:
>
>typedef int32_t vnx32si __attribute__ ((vector_size (128)));
>
> __attribute__ ((noipa)) void permute_##TYPE (TYPE values1, TYPE values2,
>\
> TYPE *out) \
> {
>\
> TYPE v
>\
> = __builtin_shufflevector (values1, values2, MASK_##NUNITS (0, NUNITS));
>\
> *(TYPE *) out = v;
>\
> }
>
> T (vnx32si, 32)
>\
>
>TEST_ALL (PERMUTE)
>
>Before this patch:
> li a4,31
> vsetvli a5,zero,e32,m8,ta,ma
> vl8re32.v v24,0(a0)
> vid.v v8
> vrsub.vx v8,v8,a4
> vrgather.vv v16,v24,v8
> vs8r.v v16,0(a2)
> ret
>
>The index vector register "v8" occupies 8 registers.
>We should optimize it into vrgatherei16.vv which is
>using int16 as the index elements.
>
>After this patch:
> vsetvli a5,zero,e16,m4,ta,ma
> li a4,31
> vid.v v4
> vl8re32.v v16,0(a0)
> vrsub.vx v4,v4,a4
> vsetvli zero,zero,e32,m8,ta,ma
> vrgatherei16.vv v8,v16,v4
> vs8r.v v8,0(a2)
> ret
>With vrgatherei16.vv, the v8 will occupy 4 registers instead
>of 8. Lower the register consuming and register pressure.
>
>PR target/111451
>
>gcc/ChangeLog:
>
>* config/riscv/riscv-v.cc (emit_vlmax_gather_insn): Optimization of
>vrgather.vv into vrgatherei16.vv.
>
>gcc/testsuite/ChangeLog:
>
>* gcc.target/riscv/rvv/autovec/vls-vlmax/perm-4.c: Adjust case.
>* gcc.target/riscv/rvv/autovec/vls/perm-4.c: Ditto.
>---
>gcc/config/riscv/riscv-v.cc | 18 ++++++++++++++++++
>.../riscv/rvv/autovec/vls-vlmax/perm-4.c | 3 ++-
>.../gcc.target/riscv/rvv/autovec/vls/perm-4.c | 3 ++-
>3 files changed, 22 insertions(+), 2 deletions(-)
>
>diff --git a/gcc/config/riscv/riscv-v.cc b/gcc/config/riscv/riscv-v.cc
>index 64a71a128d4..455efa7ea8a 100644
>--- a/gcc/config/riscv/riscv-v.cc
>+++ b/gcc/config/riscv/riscv-v.cc
>@@ -790,6 +790,24 @@ emit_vlmax_gather_insn (rtx target, rtx op, rtx sel)
> icode = code_for_pred_gather_scalar (data_mode);
> sel = elt;
> }
>+ else if (CONST_VECTOR_P (sel)
>+ && GET_MODE_BITSIZE (GET_MODE_INNER (sel_mode)) > 16
>+ && riscv_get_v_regno_alignment (data_mode) > 1)
>+ {
>+ /* If the inner mode of data is not QI or HI and data_lmul > 1,
>+ emitting vrgatherei16.vv instruction will lower register
>+ pressure.
>+ data_mode sel_mode ei16
>+ RVVM1QI RVVM1QI RVVM2HI not needed
>+ RVVM2QI RVVM2QI RVVM4HI not needed
>+ RVVM2HI RVVM2HI RVVM2HI not needed
>+ RVVM2SI RVVM2SI RVVM1HI need
>+ RVVM4SI RVVM4SI RVVM2HI need
>+ RVVM8DI RVVM8DI RVVM2HI need */
>+ PUT_MODE (sel, get_vector_mode (HImode,
>+ GET_MODE_NUNITS (data_mode)).require ());
>+ icode = code_for_pred_gatherei16 (data_mode);
>+ }
> else
> icode = code_for_pred_gather (data_mode);
> rtx ops[] = {target, op, sel};
>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 9df69a0cc2c..7ab31043547 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
>@@ -55,6 +55,7 @@
>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
>{vrgather\.vv\tv[0-9]+,\s*v[0-9]+,\s*v[0-9]+} 19 } } */
>+/* { dg-final { scan-assembler-times
>{vrgatherei16\.vv\tv[0-9]+,\s*v[0-9]+,\s*v[0-9]+} 12 } } */
>/* { dg-final { scan-assembler-times {vrsub\.vi} 24 } } */
>/* { dg-final { scan-assembler-times {vrsub\.vx} 7 } } */
>diff --git a/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls/perm-4.c
>b/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls/perm-4.c
>index 46cad8ea2f4..4d6862cf1c0 100644
>--- a/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls/perm-4.c
>+++ b/gcc/testsuite/gcc.target/riscv/rvv/autovec/vls/perm-4.c
>@@ -3,6 +3,7 @@
>#include "../vls-vlmax/perm-4.c"
>-/* { dg-final { scan-assembler-times
>{vrgather\.vv\tv[0-9]+,\s*v[0-9]+,\s*v[0-9]+} 31 } } */
>+/* { dg-final { scan-assembler-times
>{vrgather\.vv\tv[0-9]+,\s*v[0-9]+,\s*v[0-9]+} 19 } } */
>+/* { dg-final { scan-assembler-times
>{vrgatherei16\.vv\tv[0-9]+,\s*v[0-9]+,\s*v[0-9]+} 12 } } */
>/* { dg-final { scan-assembler-times {vrsub\.vi} 24 } } */
>/* { dg-final { scan-assembler-times {vrsub\.vx} 7 } } */
>--
>2.17.1
>
>
