[Bug target/112538] [RISC-V] Failed to disable V-ext autovectorization using the '--param riscv-autovec-preference=none'

[juzhe.zhong at rivai dot ai via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112538

JuzheZhong <juzhe.zhong at rivai dot ai> changed:

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                 CC|                            |juzhe.zhong at rivai dot ai

--- Comment #1 from JuzheZhong <juzhe.zhong at rivai dot ai> ---
Duplicate bug of https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112537

It generates vector codes since it is lower int __builtin_memcpy

https://godbolt.org/z/f36feoW6x

Current expanding memcpy into RVV by default as long as TARGET_VECTOR is true.

More details see expand_block_move in riscv-string.cc

Maybe you need to add 

  if (!flag_tree_vectorize)
    return false;

in expand_block_move .