https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97417
Kito Cheng <kito at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |kito at gcc dot gnu.org
--- Comment #11 from Kito Cheng <kito at gcc dot gnu.org> ---
> Two failed cases: shorten-memrefs-5.c & shorten-memrefs-6.c
Seems like shorten_memrefs pass didn't handle zero_extend and sign_extend with
memory.
You can take a look into riscv-shorten-memrefs.c:pass_shorten_memrefs::analyze
and add logic to handle zero_extend and sign_extend.
> With one instruction less, the patched one seems right and even faster to me.
> However we still need a test on sign extend and check performance
shorten_memrefs is optimize for size, the idea is transform several load
instructions with large immediate to a load immediate instruction and load
instructions with small immediate, to use C-extensions instruction as possible.
so the instruction count seems increased, but the code size is smaller.
