public inbox for gcc-cvs@sourceware.org help / color / mirror / Atom feed
From: Michael Meissner <meissner@gcc.gnu.org> To: gcc-cvs@gcc.gnu.org Subject: [gcc(refs/users/meissner/heads/work082)] Optimize vec_splats of constant vec_extract for V2DI/V2DF. Date: Wed, 23 Mar 2022 05:20:14 +0000 (GMT) [thread overview] Message-ID: <20220323052014.449CE3858427@sourceware.org> (raw) https://gcc.gnu.org/g:c54dd224dca2ed303968abaf3e7a619dfa6c8743 commit c54dd224dca2ed303968abaf3e7a619dfa6c8743 Author: Michael Meissner <meissner@linux.ibm.com> Date: Wed Mar 23 01:19:53 2022 -0400 Optimize vec_splats of constant vec_extract for V2DI/V2DF. In PR target/99293, it was pointed out that doing: vector long long dest0, dest1, src; /* ... */ dest0 = vec_splats (vec_extract (src, 0)); dest1 = vec_splats (vec_extract (src, 1)); would generate slower code. It generates the following code on power8: ;; vec_splats (vec_extract (src, 0)) xxpermdi 0,34,34,3 xxpermdi 34,0,0,0 ;; vec_splats (vec_extract (src, 1)) xxlor 0,34,34 xxpermdi 34,0,0,0 However on power9 and power10 it generates: ;; vec_splats (vec_extract (src, 0)) mfvsld 3,34 mtvsrdd 34,9,9 ;; vec_splats (vec_extract (src, 1)) mfvsrd 9,34 mtvsrdd 34,9,9 This is due to the power9 having the mfvsrld instruction which can extract either 64-bit element into a GPR. However in this case, it is better to have a single combiner pattern that can generate a single xxpermdi, instead of 2 insnsn. 2022-03-23 Michael Meissner <meissner@linux.ibm.com> gcc/ PR target/99392 * config/rs6000/vsx.md (vsx_splat_const_extract_<mode>): New insn. gcc/testsuite: PR target/99392 * gcc.target/powerpc/pr99293.c: New test. Diff: --- gcc/config/rs6000/vsx.md | 19 ++++++++++++++++ gcc/testsuite/gcc.target/powerpc/pr99293.c | 36 ++++++++++++++++++++++++++++++ 2 files changed, 55 insertions(+) diff --git a/gcc/config/rs6000/vsx.md b/gcc/config/rs6000/vsx.md index c6dc01e55e3..a1c95c61b2e 100644 --- a/gcc/config/rs6000/vsx.md +++ b/gcc/config/rs6000/vsx.md @@ -4616,6 +4616,25 @@ [(set_attr "type" "vecperm") (set_attr "isa" "p8v,*")]) +;; Optimize SPLAT of an extract from a V2DF/V2DI vector with a constant element +;; PR target/99293 +(define_insn "*vsx_splat_const_extract_<mode>" + [(set (match_operand:VSX_D 0 "vsx_register_operand" "=wa") + (vec_duplicate:VSX_D + (vec_select:<VS_scalar> + (match_operand:VSX_D 1 "vsx_register_operand" "wa") + (parallel [(match_operand 2 "const_0_to_1_operand" "n")]))))] + "VECTOR_MEM_VSX_P (<MODE>mode)" +{ + int which_word = INTVAL (operands[2]); + if (!BYTES_BIG_ENDIAN) + which_word = 1 - which_word; + + operands[3] = GEN_INT (which_word ? 3 : 0); + return "xxpermdi %x0,%x1,%x1,%3"; +} + [(set_attr "type" "vecperm")]) + ;; V4SF splat (ISA 3.0) (define_insn_and_split "vsx_splat_v4sf" [(set (match_operand:V4SF 0 "vsx_register_operand" "=wa,wa,wa") diff --git a/gcc/testsuite/gcc.target/powerpc/pr99293.c b/gcc/testsuite/gcc.target/powerpc/pr99293.c new file mode 100644 index 00000000000..13b5ed5b0b1 --- /dev/null +++ b/gcc/testsuite/gcc.target/powerpc/pr99293.c @@ -0,0 +1,36 @@ +/* { dg-do compile { target powerpc*-*-* } } */ +/* { dg-require-effective-target powerpc_vsx_ok } */ +/* { dg-options "-O2 -mvsx" } */ + +/* Test for PR 99263, which wants to do: + __builtin_vec_splats (__builtin_vec_extract (v, n)) + + where v is a V2DF or V2DI vector and n is either 0 or 1. Previously the + compiler would do a direct move to the GPR registers to select the item and + a direct move from the GPR registers to do the splat. */ + +vector long long +splat_dup_ll_0 (vector long long v) +{ + return __builtin_vec_splats (__builtin_vec_extract (v, 0)); +} + +vector long long +splat_dup_ll_1 (vector long long v) +{ + return __builtin_vec_splats (__builtin_vec_extract (v, 1)); +} + +vector double +splat_dup_d_0 (vector double v) +{ + return __builtin_vec_splats (__builtin_vec_extract (v, 0)); +} + +vector double +splat_dup_d_1 (vector double v) +{ + return __builtin_vec_splats (__builtin_vec_extract (v, 1)); +} + +/* { dg-final { scan-assembler-times "xxpermdi" 4 } } */
reply other threads:[~2022-03-23 5:20 UTC|newest] Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
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=20220323052014.449CE3858427@sourceware.org \ --to=meissner@gcc.gnu.org \ --cc=gcc-cvs@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).