[Bug rtl-optimization/122992] speed up loops with TEST_HARD_REG_BIT using EXECUTE_IF_SET_IN_HARD_REG_SET

[xry111 at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122992

--- Comment #33 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
One last comment: sometimes "easyhack" can be more difficult than we think.   I
remember I spent some time on PR62181 when I begun to work on GCC but my
attempt miserably failed and the PR is still open today (after I made hundreds
of GCC commits).