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From: "cbaylis at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/61551] New: [NEON] alter costs to allow use of post-indexed addressing modes for VLD{2..4}/VST{2..4} Date: Wed, 18 Jun 2014 14:25:00 -0000 [thread overview] Message-ID: <bug-61551-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61551 Bug ID: 61551 Summary: [NEON] alter costs to allow use of post-indexed addressing modes for VLD{2..4}/VST{2..4} Product: gcc Version: 4.10.0 Status: UNCONFIRMED Severity: enhancement Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: cbaylis at gcc dot gnu.org CC: ramana.radhakrishnan at arm dot com Target: arm-unknown-linux-gnueabi Created attachment 32967 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=32967&action=edit test for NEON addressing modes The attached test case demonstrates that GCC does not exploit the post-indexed addressing mode for NEON structure loads and stores: VLDn, VSTn where n>=2. Generated code for VLD1/VST1 (using desired post-indexed addressing) test_ld1: @ args = 0, pretend = 0, frame = 0 @ frame_needed = 0, uses_anonymous_args = 0 @ link register save eliminated. vld1.8 {d16}, [r0], r1 vst1.8 {d16}, [r0], r1 vld1.8 {d16}, [r0], r1 vst1.8 {d16}, [r0], r1 vld1.8 {d16}, [r0], r1 vst1.8 {d16}, [r0] bx lr Generated code for VLD2: test_ld2: @ args = 0, pretend = 0, frame = 0 @ frame_needed = 0, uses_anonymous_args = 0 @ link register save eliminated. adds r3, r0, r1 vld2.8 {d16-d17}, [r0] adds r0, r3, r1 adds r2, r0, r1 vst2.8 {d16-d17}, [r3] adds r3, r2, r1 vld2.8 {d16-d17}, [r0] add r1, r1, r3 vst2.8 {d16-d17}, [r2] vld2.8 {d16-d17}, [r3] vst2.8 {d16-d17}, [r1] bx lr A proof of concept patch is posted at: https://gcc.gnu.org/ml/gcc-patches/2014-06/msg01361.html
next reply other threads:[~2014-06-18 14:25 UTC|newest] Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-06-18 14:25 cbaylis at gcc dot gnu.org [this message] 2014-07-25 10:39 ` [Bug target/61551] " ramana at gcc dot gnu.org 2015-04-22 12:00 ` jakub at gcc dot gnu.org 2015-04-22 12:50 ` ramana at gcc dot gnu.org 2020-09-22 17:34 ` cbaylis at gcc dot gnu.org
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