[RFC] Merge strathegy for all-SLP vectorizer
Hi, I'd like to discuss how to go forward with getting the vectorizer to all-SLP for this stage1. While there is a personal branch with my ongoing work (users/rguenth/vect-force-slp) branches haven't proved themselves working well for collaboration. The branch isn't ready to be merged in full but I have been picking improvements to trunk last stage1 and some remaining bits in the past weeks. I have refrained from merging code paths that cannot be exercised on trunk. There are two important set of changes on the branch, both critical to get more testing on non-x86 targets. 1. enable single-lane SLP discovery 2. avoid splitting store groups (9315bfc661432c3 and 4336060fe2db8ec if you fetch the branch) The first point is also most annoying on the testsuite since doing SLP instead of interleaving changes what we dump and thus tests start to fail in random ways when you switch between both modes. On the branch single-lane SLP discovery is gated with --param vect-single-lane-slp. The branch has numerous changes to enable single-lane SLP for some code paths that have SLP not implemented and where I did not bother to try supporting multi-lane SLP at this point. It also adds more SLP discovery entry points. I'm not sure how to try merging these pieces to allow others to more easily help out. One possibility is to merge --param vect-single-lane-slp defaulted off and pick dependent changes even when they cause testsuite regressions with vect-single-lane-slp=1. Alternatively adjust the testsuite by adding --param vect-single-lane-slp=0 and default to 1 (or keep the default). Or require a clean testsuite with --param vect-single-lane-slp defaulted to 1 but keep the --param for debugging (and allow FAILs with 0). For fun I merged just single-lane discovery of non-grouped stores and have that enabled by default. On x86_64 this results in the set of FAILs below. Any suggestions? Thanks, Richard. FAIL: gcc.dg/vect/O3-pr39675-2.c scan-tree-dump-times vect "vectorizing stmts using SLP" 1 XPASS: gcc.dg/vect/no-scevccp-outer-12.c scan-tree-dump-times vect "OUTER LOOP VECTORIZED." 1 FAIL: gcc.dg/vect/no-section-anchors-vect-31.c scan-tree-dump-times vect "Alignment of access forced using peeling" 2 FAIL: gcc.dg/vect/no-section-anchors-vect-31.c scan-tree-dump-times vect "Vectorizing an unaligned access" 0 FAIL: gcc.dg/vect/no-section-anchors-vect-64.c scan-tree-dump-times vect "Alignment of access forced using peeling" 2 FAIL: gcc.dg/vect/no-section-anchors-vect-64.c scan-tree-dump-times vect "Vectorizing an unaligned access" 0 FAIL: gcc.dg/vect/no-section-anchors-vect-66.c scan-tree-dump-times vect "Alignment of access forced using peeling" 1 FAIL: gcc.dg/vect/no-section-anchors-vect-66.c scan-tree-dump-times vect "Vectorizing an unaligned access" 0 FAIL: gcc.dg/vect/no-section-anchors-vect-68.c scan-tree-dump-times vect "Alignment of access forced using peeling" 2 FAIL: gcc.dg/vect/no-section-anchors-vect-68.c scan-tree-dump-times vect "Vectorizing an unaligned access" 0 FAIL: gcc.dg/vect/slp-12a.c -flto -ffat-lto-objects scan-tree-dump-times vect "vectorizing stmts using SLP" 1 FAIL: gcc.dg/vect/slp-12a.c scan-tree-dump-times vect "vectorizing stmts using SLP" 1 FAIL: gcc.dg/vect/slp-19a.c -flto -ffat-lto-objects scan-tree-dump-times vect "vectorizing stmts using SLP" 1 FAIL: gcc.dg/vect/slp-19a.c scan-tree-dump-times vect "vectorizing stmts using SLP" 1 FAIL: gcc.dg/vect/slp-19b.c -flto -ffat-lto-objects scan-tree-dump-times vect "vectorizing stmts using SLP" 1 FAIL: gcc.dg/vect/slp-19b.c scan-tree-dump-times vect "vectorizing stmts using SLP" 1 FAIL: gcc.dg/vect/slp-19c.c -flto -ffat-lto-objects scan-tree-dump-times vect "vectorized 1 loops" 1 FAIL: gcc.dg/vect/slp-19c.c -flto -ffat-lto-objects scan-tree-dump-times vect "vectorizing stmts using SLP" 1 FAIL: gcc.dg/vect/slp-19c.c scan-tree-dump-times vect "vectorized 1 loops" 1 FAIL: gcc.dg/vect/slp-19c.c scan-tree-dump-times vect "vectorizing stmts using SLP" 1 XPASS: gcc.dg/vect/tsvc/vect-tsvc-s1115.c -flto -ffat-lto-objects scan-tree-dump vect "vectorized 1 loops" XPASS: gcc.dg/vect/tsvc/vect-tsvc-s1115.c scan-tree-dump vect "vectorized 1 loops" XPASS: gcc.dg/vect/tsvc/vect-tsvc-s114.c -flto -ffat-lto-objects scan-tree-dump vect "vectorized 1 loops" XPASS: gcc.dg/vect/tsvc/vect-tsvc-s114.c scan-tree-dump vect "vectorized 1 loops" XPASS: gcc.dg/vect/tsvc/vect-tsvc-s1232.c -flto -ffat-lto-objects scan-tree-dump vect "vectorized 1 loops" XPASS: gcc.dg/vect/tsvc/vect-tsvc-s1232.c scan-tree-dump vect "vectorized 1 loops" XPASS: gcc.dg/vect/tsvc/vect-tsvc-s257.c -flto -ffat-lto-objects scan-tree-dump vect "vectorized 1 loops" XPASS: gcc.dg/vect/tsvc/vect-tsvc-s257.c scan-tree-dump vect "vectorized 1 loops" FAIL: gcc.dg/vect/vect-26.c -flto -ffat-lto-objects scan-tree-dump-times vect "Alignment of access forced using peeling" 1 FAIL: gcc.dg/vect/vect-26.c -flto -ffat-lto-objects scan-tree-dump-times vect "Vector
Re: [RFC] Merge strathegy for all-SLP vectorizer
Richard Biener via Gcc writes: > Hi, > > I'd like to discuss how to go forward with getting the vectorizer to > all-SLP for this stage1. While there is a personal branch with my > ongoing work (users/rguenth/vect-force-slp) branches haven't proved > themselves working well for collaboration. Speaking for myself, the problem hasn't been so much the branch as lack of time. I've been pretty swamped the last eight months of so (except for the time that I took off, which admittedly was quite a bit!), and so I never even got around to properly reading and replying to your message after the Cauldron. It's been on the "this is important, I should make time to read and understand it properly" list all this time. Sorry about that. :( I'm hoping to have time to work/help out on SLP stuff soon. > The branch isn't ready to be merged in full but I have been picking > improvements to trunk last stage1 and some remaining bits in the past > weeks. I have refrained from merging code paths that cannot be > exercised on trunk. > > There are two important set of changes on the branch, both critical > to get more testing on non-x86 targets. > > 1. enable single-lane SLP discovery > 2. avoid splitting store groups (9315bfc661432c3 and 4336060fe2db8ec > if you fetch the branch) > > The first point is also most annoying on the testsuite since doing > SLP instead of interleaving changes what we dump and thus tests > start to fail in random ways when you switch between both modes. > On the branch single-lane SLP discovery is gated with > --param vect-single-lane-slp. > > The branch has numerous changes to enable single-lane SLP for some > code paths that have SLP not implemented and where I did not bother > to try supporting multi-lane SLP at this point. It also adds more > SLP discovery entry points. > > I'm not sure how to try merging these pieces to allow others to > more easily help out. One possibility is to merge > --param vect-single-lane-slp defaulted off and pick dependent > changes even when they cause testsuite regressions with > vect-single-lane-slp=1. Alternatively adjust the testsuite by > adding --param vect-single-lane-slp=0 and default to 1 > (or keep the default). FWIW, this one sounds good to me (the default to 1 version). I.e. mechanically add --param vect-single-lane-slp=0 to any tests that fail with the new default. That means that the test that need fixing are easily greppable for anyone who wants to help. Sometimes it'll just be a test update. Sometimes it will be new vectoriser code. Thanks, Richard > Or require a clean testsuite with > --param vect-single-lane-slp defaulted to 1 but keep the --param > for debugging (and allow FAILs with 0). > > For fun I merged just single-lane discovery of non-grouped stores > and have that enabled by default. On x86_64 this results in the > set of FAILs below. > > Any suggestions? > > Thanks, > Richard. > > FAIL: gcc.dg/vect/O3-pr39675-2.c scan-tree-dump-times vect "vectorizing > stmts using SLP" 1 > XPASS: gcc.dg/vect/no-scevccp-outer-12.c scan-tree-dump-times vect "OUTER > LOOP VECTORIZED." 1 > FAIL: gcc.dg/vect/no-section-anchors-vect-31.c scan-tree-dump-times vect > "Alignment of access forced using peeling" 2 > FAIL: gcc.dg/vect/no-section-anchors-vect-31.c scan-tree-dump-times vect > "Vectorizing an unaligned access" 0 > FAIL: gcc.dg/vect/no-section-anchors-vect-64.c scan-tree-dump-times vect > "Alignment of access forced using peeling" 2 > FAIL: gcc.dg/vect/no-section-anchors-vect-64.c scan-tree-dump-times vect > "Vectorizing an unaligned access" 0 > FAIL: gcc.dg/vect/no-section-anchors-vect-66.c scan-tree-dump-times vect > "Alignment of access forced using peeling" 1 > FAIL: gcc.dg/vect/no-section-anchors-vect-66.c scan-tree-dump-times vect > "Vectorizing an unaligned access" 0 > FAIL: gcc.dg/vect/no-section-anchors-vect-68.c scan-tree-dump-times vect > "Alignment of access forced using peeling" 2 > FAIL: gcc.dg/vect/no-section-anchors-vect-68.c scan-tree-dump-times vect > "Vectorizing an unaligned access" 0 > FAIL: gcc.dg/vect/slp-12a.c -flto -ffat-lto-objects scan-tree-dump-times > vect "vectorizing stmts using SLP" 1 > FAIL: gcc.dg/vect/slp-12a.c scan-tree-dump-times vect "vectorizing stmts > using SLP" 1 > FAIL: gcc.dg/vect/slp-19a.c -flto -ffat-lto-objects scan-tree-dump-times > vect "vectorizing stmts using SLP" 1 > FAIL: gcc.dg/vect/slp-19a.c scan-tree-dump-times vect "vectorizing stmts > using SLP" 1 > FAIL: gcc.dg/vect/slp-19b.c -flto -ffat-lto-objects scan-tree-dump-times > vect "vectorizing stmts using SLP" 1 > FAIL: gcc.dg/vect/slp-19b.c scan-tree-dump-times vect "vectorizing stmts > using SLP" 1 > FAIL: gcc.dg/vect/slp-19c.c -flto -ffat-lto-objects scan-tree-dump-times > vect "vectorized 1 loops" 1 > FAIL: gcc.dg/vect/slp-19c.c -flto -ffat-lto-objects scan-tree-dump-times > vect "vectorizing stmts using SLP" 1 > FAIL: gcc.dg/vect/slp-19c.c scan-tree-dump-times vect "vectorized 1 loops" > 1 > FAIL: gcc.dg
Re: [RFC] Merge strathegy for all-SLP vectorizer
On Fri, 17 May 2024, Richard Sandiford wrote: > Richard Biener via Gcc writes: > > Hi, > > > > I'd like to discuss how to go forward with getting the vectorizer to > > all-SLP for this stage1. While there is a personal branch with my > > ongoing work (users/rguenth/vect-force-slp) branches haven't proved > > themselves working well for collaboration. > > Speaking for myself, the problem hasn't been so much the branch as > lack of time. I've been pretty swamped the last eight months of so > (except for the time that I took off, which admittedly was quite a > bit!), and so I never even got around to properly reading and replying > to your message after the Cauldron. It's been on the "this is important, > I should make time to read and understand it properly" list all this time. > Sorry about that. :( > > I'm hoping to have time to work/help out on SLP stuff soon. > > > The branch isn't ready to be merged in full but I have been picking > > improvements to trunk last stage1 and some remaining bits in the past > > weeks. I have refrained from merging code paths that cannot be > > exercised on trunk. > > > > There are two important set of changes on the branch, both critical > > to get more testing on non-x86 targets. > > > > 1. enable single-lane SLP discovery > > 2. avoid splitting store groups (9315bfc661432c3 and 4336060fe2db8ec > > if you fetch the branch) > > > > The first point is also most annoying on the testsuite since doing > > SLP instead of interleaving changes what we dump and thus tests > > start to fail in random ways when you switch between both modes. > > On the branch single-lane SLP discovery is gated with > > --param vect-single-lane-slp. > > > > The branch has numerous changes to enable single-lane SLP for some > > code paths that have SLP not implemented and where I did not bother > > to try supporting multi-lane SLP at this point. It also adds more > > SLP discovery entry points. > > > > I'm not sure how to try merging these pieces to allow others to > > more easily help out. One possibility is to merge > > --param vect-single-lane-slp defaulted off and pick dependent > > changes even when they cause testsuite regressions with > > vect-single-lane-slp=1. Alternatively adjust the testsuite by > > adding --param vect-single-lane-slp=0 and default to 1 > > (or keep the default). > > FWIW, this one sounds good to me (the default to 1 version). > I.e. mechanically add --param vect-single-lane-slp=0 to any tests > that fail with the new default. That means that the test that need > fixing are easily greppable for anyone who wants to help. Sometimes > it'll just be a test update. Sometimes it will be new vectoriser code. OK. Meanwhile I figured the most important part is 2. from above since that enables the single-lane in a grouped access (also covering single element interleaving). This will cover all problematical cases with respect to vectorizing loads and stores. It also has less testsuite fallout, mainly because we have a lot less coverage for grouped stores without SLP. So I'll see to produce a mergeable patch for part 2 and post that for review next week. Thanks, Richard. > Thanks, > Richard > > > Or require a clean testsuite with > > --param vect-single-lane-slp defaulted to 1 but keep the --param > > for debugging (and allow FAILs with 0). > > > > For fun I merged just single-lane discovery of non-grouped stores > > and have that enabled by default. On x86_64 this results in the > > set of FAILs below. > > > > Any suggestions? > > > > Thanks, > > Richard. > > > > FAIL: gcc.dg/vect/O3-pr39675-2.c scan-tree-dump-times vect "vectorizing > > stmts using SLP" 1 > > XPASS: gcc.dg/vect/no-scevccp-outer-12.c scan-tree-dump-times vect "OUTER > > LOOP VECTORIZED." 1 > > FAIL: gcc.dg/vect/no-section-anchors-vect-31.c scan-tree-dump-times vect > > "Alignment of access forced using peeling" 2 > > FAIL: gcc.dg/vect/no-section-anchors-vect-31.c scan-tree-dump-times vect > > "Vectorizing an unaligned access" 0 > > FAIL: gcc.dg/vect/no-section-anchors-vect-64.c scan-tree-dump-times vect > > "Alignment of access forced using peeling" 2 > > FAIL: gcc.dg/vect/no-section-anchors-vect-64.c scan-tree-dump-times vect > > "Vectorizing an unaligned access" 0 > > FAIL: gcc.dg/vect/no-section-anchors-vect-66.c scan-tree-dump-times vect > > "Alignment of access forced using peeling" 1 > > FAIL: gcc.dg/vect/no-section-anchors-vect-66.c scan-tree-dump-times vect > > "Vectorizing an unaligned access" 0 > > FAIL: gcc.dg/vect/no-section-anchors-vect-68.c scan-tree-dump-times vect > > "Alignment of access forced using peeling" 2 > > FAIL: gcc.dg/vect/no-section-anchors-vect-68.c scan-tree-dump-times vect > > "Vectorizing an unaligned access" 0 > > FAIL: gcc.dg/vect/slp-12a.c -flto -ffat-lto-objects scan-tree-dump-times > > vect "vectorizing stmts using SLP" 1 > > FAIL: gcc.dg/vect/slp-12a.c scan-tree-dump-times vect "vectorizing stmts > > using SLP" 1 > > FAIL: gcc.dg/vect/slp
gcc-13-20240517 is now available
Snapshot gcc-13-20240517 is now available on https://gcc.gnu.org/pub/gcc/snapshots/13-20240517/ and on various mirrors, see https://gcc.gnu.org/mirrors.html for details. This snapshot has been generated from the GCC 13 git branch with the following options: git://gcc.gnu.org/git/gcc.git branch releases/gcc-13 revision 5b5342e6a38d4b28fdf4e607d30ca6bde87ba010 You'll find: gcc-13-20240517.tar.xz Complete GCC SHA256=86e69748ed375e191fcce6f7650603cc3fc96d81b094b45e4efca5af0f467533 SHA1=d74ed5647af083d3255e033d08907d426a881c2c Diffs from 13-20240510 are available in the diffs/ subdirectory. When a particular snapshot is ready for public consumption the LATEST-13 link is updated and a message is sent to the gcc list. Please do not use a snapshot before it has been announced that way.
