On 8/4/2026 5:03 AM, Robin Dapp wrote:
Hi,
In expand_const_vector_single_step_npatterns, we use a second vector
builder that is derived from the main one, in order to create a
different alternating pattern for constant synthesis. We later use the
second builder's number of patterns for creating an intermediate
operation. The second builder can have a different number of patterns
than the first one, however, for example when its "global" pattern is
simpler.
This patch uses npatterns from the original builder.
Regtested on rv64gcv_zvl512b.
It's surprising that this went unnoticed for so long. Definitely
requires backporting to 16, 15, and maybe 14.
Regards
Robin
PR target/126550
gcc/ChangeLog:
* config/riscv/riscv-v.cc (expand_const_vector_single_step_npatterns):
User global builder's npatterns.
gcc/testsuite/ChangeLog:
* gcc.target/riscv/rvv/autovec/pr126550-2.c: New test.
* gcc.target/riscv/rvv/autovec/pr126550.c: New test.
LGTM.
jeff
