public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
From: "guojiufu at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/108338] New: use mtvsrws for lowpart DI->SF conversion on P9 Date: Mon, 09 Jan 2023 06:35:40 +0000 [thread overview] Message-ID: <bug-108338-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108338 Bug ID: 108338 Summary: use mtvsrws for lowpart DI->SF conversion on P9 Product: gcc Version: 13.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: guojiufu at gcc dot gnu.org Target Milestone: --- In a mail-list discussion, https://gcc.gnu.org/pipermail/gcc-patches/2022-December/609054.html, as Segher points out, we could use 'mtvsrws' for the conversion from lowpart DI to SF on P9; and use 'mtvsrd' for the conversion from highpart of DI to SF. float sf_from_di_off0 (long l) { char buff[16]; *(long*)buff = l; float f = *(float*)(buff); return f; } float sf_from_di_off4 (long l) { char buff[16]; *(long*)buff = l; float f = *(float*)(buff + 4); return f; } With trunk, -O2 -mcpu=power9, the asm code could be optimized. sldi 9,3,32 mtvsrd 1,9 xscvspdpn 1,1 blr ==> mtvsrws;xscvspdpn (p9 LE) lowpart srdi 3,3,32 sldi 9,3,32 mtvsrd 1,9 xscvspdpn 1,1 blr ==> (+ clean lowpart to 0) mtvsrd;xscvspdpn highpart
next reply other threads:[~2023-01-09 6:35 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-01-09 6:35 guojiufu at gcc dot gnu.org [this message] 2023-10-07 7:57 ` [Bug target/108338] " cvs-commit at gcc dot gnu.org 2023-10-07 7:57 ` cvs-commit at gcc dot gnu.org 2023-10-07 8:03 ` guojiufu at gcc dot gnu.org
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=bug-108338-4@http.gcc.gnu.org/bugzilla/ \ --to=gcc-bugzilla@gcc.gnu.org \ --cc=gcc-bugs@gcc.gnu.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).