https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68110
--- Comment #4 from Marc Glisse ---
(separately from the missing DCE at RTL level)
Replacing __builtin_sub_overflow (a, b, ) with a < b when r is unused is
something we could already easily do at the GIMPLE level, but since we don't
have any
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68110
--- Comment #3 from Paul Eggert ---
(In reply to Andrew Pinski from comment #2)
> So the question is does anyone use this function without "a - b" later on?
Not that I know of. The usual pattern for callers of the Gnulib macro is to use
the
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68110
--- Comment #5 from Richard Biener ---
value-numbering would need to special-case them via the insertion trick it does
for conversions. somehow. not sure if feasible or worthwhile.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68110
Andrew Pinski changed:
What|Removed |Added
Target||x86_64*-* i686-*-*
Component|c
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68110
--- Comment #2 from Andrew Pinski ---
So the question is does anyone use this function without "a - b" later on? If
not then it is just a microbenchmark of this code is showing the regression and
I would say the microbenchmark is wrong.
