public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
From: "alalaw01 at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/35226] Induction with multiplication are not vectorized Date: Thu, 30 Apr 2015 11:28:00 -0000 [thread overview] Message-ID: <bug-35226-4-LyLoGaqOnY@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-35226-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=35226 alalaw01 at gcc dot gnu.org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2015-04-30 CC| |alalaw01 at gcc dot gnu.org Version|4.3.0 |6.0 Summary|Reduction and induction |Induction with |with multiplication are not |multiplication are not |vectorized |vectorized Ever confirmed|0 |1 --- Comment #1 from alalaw01 at gcc dot gnu.org --- Multiplication reductions are supported, certainly in gcc 4.9, I think longer. However, the following induction does not vectorize on gcc 6 development branch (x86_64, -O3, with or without -mavx or -msse2): int a[24]; int main (int argc, char **argv) { int p = 1; for (int i = 0; i < 24; i++, p*=2) a[i] *= p; } -fdump-tree-vect-details suggests the multiplication is recognized as a reduction but not as an induction: test_induc.c:7:3: note: Analyze phi: p_13 = PHI <p_9(4), 1(2)> test_induc.c:7:3: note: reduction used in loop. test_induc.c:7:3: note: Unknown def-use cycle pattern. test_induc.c:7:3: note: === vect_pattern_recog === test_induc.c:7:3: note: vect_is_simple_use: operand _5 test_induc.c:7:3: note: def_stmt: _5 = a[i_14]; test_induc.c:7:3: note: type of def: 3. test_induc.c:7:3: note: vect_is_simple_use: operand p_13 test_induc.c:7:3: note: def_stmt: p_13 = PHI <p_9(4), 1(2)> test_induc.c:7:3: note: Unsupported pattern. ... test_induc.c:7:3: note: def_stmt: p_13 = PHI <p_9(4), 1(2)> test_induc.c:7:3: note: Unsupported pattern. test_induc.c:7:3: note: not vectorized: unsupported use in stmt. test_induc.c:7:3: note: unexpected pattern. test_induc.c:4:1: note: vectorized 0 loops in function. ... <bb 3>: # p_13 = PHI <p_9(4), 1(2)> ... p_9 = p_13 * 2;
next parent reply other threads:[~2015-04-30 11:28 UTC|newest] Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <bug-35226-4@http.gcc.gnu.org/bugzilla/> 2015-04-30 11:28 ` alalaw01 at gcc dot gnu.org [this message] 2024-03-18 7:14 ` pinskia at gcc dot gnu.org 2024-03-18 7:29 ` pinskia 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-35226-4-LyLoGaqOnY@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).