>> unsigned int elen = TARGET_VECTOR_ELEN_64 ? 64 : 32;
Add comment here to demonstrate why you pick up elen to set the LIMIT.
I understand:
1. -march=zve32* ===> ELEN = 32
    -march=zve64* ===> ELEN = 64
2. both vmv.v.x/vmv.s.x is restrict to the ELEN
    For example, When ELEN=32 (-march=zve32*)
    vsetvli ...e64,m1
    vmv.v.x/vmv.s.x
    We can't support such code sequence.

You should demonstrate it clearly in the comments.

Otherwise, this patch LGTM.


juzhe.zhong@rivai.ai
 
From: pan2.li
Date: 2023-06-14 08:58
To: gcc-patches
CC: juzhe.zhong; rdapp.gcc; jeffreyalaw; pan2.li; yanzhang.wang; kito.cheng
Subject: [PATCH v1] RISC-V: Bugfix for vec_init repeating auto vectorization in RV32
From: Pan Li <pan2.li@intel.com>
 
This patch would like to fix one bug exported by RV32 test case
multiple_rgroup_run-2.c. The mask should be restricted by elen in
vector, and the condition between the vmv.s.x and the vmv.v.x should
take inner_bits_size rather than constants.
 
Passed both the rv32 and rv64 riscv/rvv tests.
 
Signed-off-by: Pan Li <pan2.li@intel.com>
 
gcc/ChangeLog:
 
* config/riscv/riscv-v.cc (rvv_builder::get_merge_scalar_mask):
Take elen instead of scalar BITS_PER_WORD.
(expand_vector_init_merge_repeating_sequence): Use inner_bits_size
instead of scaler BITS_PER_WORD.
---
gcc/config/riscv/riscv-v.cc | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
 
diff --git a/gcc/config/riscv/riscv-v.cc b/gcc/config/riscv/riscv-v.cc
index fb970344521..9270e258ca3 100644
--- a/gcc/config/riscv/riscv-v.cc
+++ b/gcc/config/riscv/riscv-v.cc
@@ -399,10 +399,11 @@ rvv_builder::get_merge_scalar_mask (unsigned int index_in_pattern) const
{
   unsigned HOST_WIDE_INT mask = 0;
   unsigned HOST_WIDE_INT base_mask = (1ULL << index_in_pattern);
+  unsigned int elen = TARGET_VECTOR_ELEN_64 ? 64 : 32;
-  gcc_assert (BITS_PER_WORD % npatterns () == 0);
+  gcc_assert (elen % npatterns () == 0);
-  int limit = BITS_PER_WORD / npatterns ();
+  int limit = elen / npatterns ();
   for (int i = 0; i < limit; i++)
     mask |= base_mask << (i * npatterns ());
@@ -1923,7 +1924,7 @@ expand_vector_init_merge_repeating_sequence (rtx target,
       rtx mask = gen_reg_rtx (mask_mode);
       rtx dup = gen_reg_rtx (dup_mode);
-      if (full_nelts <= BITS_PER_WORD) /* vmv.s.x.  */
+      if (full_nelts <= builder.inner_bits_size ()) /* vmv.s.x.  */
{
  rtx ops[] = {dup, gen_scalar_move_mask (dup_mask_mode),
    RVV_VUNDEF (dup_mode), merge_mask};
@@ -1933,7 +1934,8 @@ expand_vector_init_merge_repeating_sequence (rtx target,
       else /* vmv.v.x.  */
{
  rtx ops[] = {dup, force_reg (GET_MODE_INNER (dup_mode), merge_mask)};
-   rtx vl = gen_int_mode (CEIL (full_nelts, BITS_PER_WORD), Pmode);
+   rtx vl = gen_int_mode (CEIL (full_nelts, builder.inner_bits_size ()),
+ Pmode);
  emit_nonvlmax_integer_move_insn (code_for_pred_broadcast (dup_mode),
   ops, vl);
}
-- 
2.34.1