https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86819
Bug ID: 86819
Summary: Set min_divisions_for_recip_mul to 2
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: glisse at gcc dot gnu.org
Target Milestone: ---
Target: x86_64-*-*
On a modern x86_64, multiplications are super fast and divisions are much
slower, so as soon as we have 2 divisions by the same number, it is faster to
precompute the inverse. There is TARGET_MIN_DIVISIONS_FOR_RECIP_MUL for this
purpose, I believe we should use it to set the threshold to 2 (the default is
3).
