On Mon, Aug 16, 2021 at 8:48 PM Andrew Pinski via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > On Mon, Aug 16, 2021 at 9:15 AM Jirui Wu via Gcc-patches > <gcc-patches@gcc.gnu.org> wrote: > > > > Hi all, > > > > This patch generates FRINTZ instruction to optimize type casts. > > > > The changes in this patch covers: > > * Opimization of a FIX_TRUNC_EXPR cast inside a FLOAT_EXPR using IFN_TRUNC. > > * Change of corresponding test cases. > > > > Regtested on aarch64-none-linux-gnu and no issues. > > > > Ok for master? If OK can it be committed for me, I have no commit rights. > > Is there a reason why you are doing the transformation manually inside > forwprop rather than handling it inside match.pd? > Also can't this only be done for -ffast-math case?
You definitely have to look at the intermediate type - that could be a uint8_t or even a boolean type. So unless the intermediate type can represent all float values optimizing to trunc() is invalid. Also if you emit IFN_TRUNC you have to make sure there's target support - we don't emit calls to a library trunc() from an internal function call (and we wouldn't want to optimize it that way). Richard. > > Thanks, > Andrew Pinski > > > > > Thanks, > > Jirui > > > > gcc/ChangeLog: > > > > * tree-ssa-forwprop.c (pass_forwprop::execute): Optimize with > > frintz. > > > > > > gcc/testsuite/ChangeLog: > > > > * gcc.target/aarch64/fix_trunc1.c: Update to new expectation.
