commit: 8cd7b247ed5101dbf81e3bf761f15207319aa2d4 Author: Sam James <sam <AT> gentoo <DOT> org> AuthorDate: Mon Apr 7 07:07:29 2025 +0000 Commit: Sam James <sam <AT> gentoo <DOT> org> CommitDate: Mon Apr 7 07:07:29 2025 +0000 URL: https://gitweb.gentoo.org/proj/gcc-patches.git/commit/?id=8cd7b247
15.0.0: drop combine patches merged upstream Signed-off-by: Sam James <sam <AT> gentoo.org> ...ow-2-2-combinations-but-with-a-tweak-PR11.patch | 204 ------------------ ...id-split_i2i3-search-if-i2-is-unchanged-P.patch | 54 ----- ...Optimise-distribute_links-search-PR116398.patch | 99 --------- ...it-insn-searchs-for-2-2-combinations-PR11.patch | 240 --------------------- ...implify-rtx-Fix-shortcut-for-vector-eq-ne.patch | 131 ----------- 15.0.0/gentoo/README.history | 5 + 6 files changed, 5 insertions(+), 728 deletions(-) diff --git a/15.0.0/gentoo/83_all_combine-Allow-2-2-combinations-but-with-a-tweak-PR11.patch b/15.0.0/gentoo/83_all_combine-Allow-2-2-combinations-but-with-a-tweak-PR11.patch deleted file mode 100644 index fd85bcd..0000000 --- a/15.0.0/gentoo/83_all_combine-Allow-2-2-combinations-but-with-a-tweak-PR11.patch +++ /dev/null @@ -1,204 +0,0 @@ -https://inbox.sourceware.org/gcc-patches/[email protected]/ - -From de2f5e9c4ce4bb674fb0da191102838a6bdd92f6 Mon Sep 17 00:00:00 2001 -Message-ID: <de2f5e9c4ce4bb674fb0da191102838a6bdd92f6.1743793443.git....@gentoo.org> -From: Richard Sandiford <[email protected]> -Date: Fri, 4 Apr 2025 10:21:43 +0100 -Subject: [PATCH 1/4] combine: Allow 2->2 combinations, but with a tweak - [PR116398] - -One of the problems in PR101523 was that, after each successful -2->2 combination attempt, try_combine would restart combination -attempts at i2 even if i2 hadn't changed. This led to quadratic -behaviour as the same failed combinations between i2 and i3 were -tried repeatedly. - -The original patch for the PR dealt with that by disallowing 2->2 -combinations. However, that led to various optimisation regressions, -so there was interest in allowing the combinations again, at least -until an alternative way of getting the same results is in place. - -This patch is a variant of Richi's in: - - https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101523#c53 - -but limited to when we're combining 2 instructions. - -This speeds up combine by 10x on the original PR101523 testcase -and reduces combine's memory footprint by 100x. - -gcc/ - PR testsuite/116398 - * combine.cc (try_combine): Reallow 2->2 combinations. Detect when - only i3 has changed and restart from i3 in that case. - -gcc/testsuite/ - * gcc.target/aarch64/popcnt-le-1.c: Account for commutativity of TST. - * gcc.target/aarch64/popcnt-le-3.c: Likewise AND. - * gcc.target/aarch64/sve/pred-not-gen-1.c: Revert previous patch. - * gcc.target/aarch64/sve/pred-not-gen-4.c: Likewise. - * gcc.target/aarch64/sve/var_stride_2.c: Likewise. - * gcc.target/aarch64/sve/var_stride_4.c: Likewise. - -Co-authored-by: Richard Biener <[email protected]> ---- - gcc/combine.cc | 14 ++++---------- - gcc/testsuite/gcc.target/aarch64/popcnt-le-1.c | 4 ++-- - gcc/testsuite/gcc.target/aarch64/popcnt-le-3.c | 4 ++-- - gcc/testsuite/gcc.target/aarch64/pr100056.c | 4 +++- - .../gcc.target/aarch64/sve/pred-not-gen-1.c | 4 ++-- - .../gcc.target/aarch64/sve/pred-not-gen-4.c | 4 ++-- - .../gcc.target/aarch64/sve/var_stride_2.c | 3 ++- - .../gcc.target/aarch64/sve/var_stride_4.c | 3 ++- - 8 files changed, 19 insertions(+), 21 deletions(-) - -diff --git a/gcc/combine.cc b/gcc/combine.cc -index 1b6c4e314cc9..65a87a45b3be 100644 ---- a/gcc/combine.cc -+++ b/gcc/combine.cc -@@ -4210,16 +4210,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0, - adjust_for_new_dest (i3); - } - -- /* If I2 didn't change, this is not a combination (but a simplification or -- canonicalisation with context), which should not be done here. Doing -- it here explodes the algorithm. Don't. */ -- if (rtx_equal_p (newi2pat, PATTERN (i2))) -- { -- if (dump_file) -- fprintf (dump_file, "i2 didn't change, not doing this\n"); -- undo_all (); -- return 0; -- } -+ bool only_i3_changed = !i0 && !i1 && rtx_equal_p (newi2pat, PATTERN (i2)); - - /* We now know that we can do this combination. Merge the insns and - update the status of registers and LOG_LINKS. */ -@@ -4787,6 +4778,9 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0, - combine_successes++; - undo_commit (); - -+ if (only_i3_changed) -+ return i3; -+ - rtx_insn *ret = newi2pat ? i2 : i3; - if (added_links_insn && DF_INSN_LUID (added_links_insn) < DF_INSN_LUID (ret)) - ret = added_links_insn; -diff --git a/gcc/testsuite/gcc.target/aarch64/popcnt-le-1.c b/gcc/testsuite/gcc.target/aarch64/popcnt-le-1.c -index b4141da982c9..843fdac9fd8e 100644 ---- a/gcc/testsuite/gcc.target/aarch64/popcnt-le-1.c -+++ b/gcc/testsuite/gcc.target/aarch64/popcnt-le-1.c -@@ -8,7 +8,7 @@ - /* - ** le32: - ** sub w([0-9]+), w0, #1 --** tst w0, w\1 -+** tst (?:w0, w\1|w\1, w0) - ** cset w0, eq - ** ret - */ -@@ -20,7 +20,7 @@ unsigned le32 (const unsigned int a) { - /* - ** gt32: - ** sub w([0-9]+), w0, #1 --** tst w0, w\1 -+** tst (?:w0, w\1|w\1, w0) - ** cset w0, ne - ** ret - */ -diff --git a/gcc/testsuite/gcc.target/aarch64/popcnt-le-3.c b/gcc/testsuite/gcc.target/aarch64/popcnt-le-3.c -index b811e6f6e8fe..3b558e95d819 100644 ---- a/gcc/testsuite/gcc.target/aarch64/popcnt-le-3.c -+++ b/gcc/testsuite/gcc.target/aarch64/popcnt-le-3.c -@@ -8,7 +8,7 @@ - /* - ** le16: - ** sub w([0-9]+), w0, #1 --** and w([0-9]+), w0, w\1 -+** and w([0-9]+), (?:w0, w\1|w\1, w0) - ** tst w\2, 65535 - ** cset w0, eq - ** ret -@@ -21,7 +21,7 @@ unsigned le16 (const unsigned short a) { - /* - ** gt16: - ** sub w([0-9]+), w0, #1 --** and w([0-9]+), w0, w\1 -+** and w([0-9]+), (?:w0, w\1|w\1, w0) - ** tst w\2, 65535 - ** cset w0, ne - ** ret -diff --git a/gcc/testsuite/gcc.target/aarch64/pr100056.c b/gcc/testsuite/gcc.target/aarch64/pr100056.c -index 0b77824da457..70499772d285 100644 ---- a/gcc/testsuite/gcc.target/aarch64/pr100056.c -+++ b/gcc/testsuite/gcc.target/aarch64/pr100056.c -@@ -1,7 +1,9 @@ - /* PR target/100056 */ - /* { dg-do compile } */ - /* { dg-options "-O2" } */ --/* { dg-final { scan-assembler-not {\t[us]bfiz\tw[0-9]+, w[0-9]+, 11} } } */ -+/* { dg-final { scan-assembler-not {\t[us]bfiz\tw[0-9]+, w[0-9]+, 11} { xfail *-*-* } } } */ -+/* { dg-final { scan-assembler-times {\t[us]bfiz\tw[0-9]+, w[0-9]+, 11} 2 } } */ -+/* { dg-final { scan-assembler-times {\tadd\tw[0-9]+, w[0-9]+, w[0-9]+, uxtb\n} 2 } } */ - - int - or_shift_u8 (unsigned char i) -diff --git a/gcc/testsuite/gcc.target/aarch64/sve/pred-not-gen-1.c b/gcc/testsuite/gcc.target/aarch64/sve/pred-not-gen-1.c -index a7d2795ebe23..c9a8b82c48ac 100644 ---- a/gcc/testsuite/gcc.target/aarch64/sve/pred-not-gen-1.c -+++ b/gcc/testsuite/gcc.target/aarch64/sve/pred-not-gen-1.c -@@ -19,6 +19,6 @@ void f10(double * restrict z, double * restrict w, double * restrict x, double * - } - } - --/* { dg-final { scan-assembler-not {\tbic\t} { xfail *-*-* } } } */ --/* { dg-final { scan-assembler-times {\tnot\tp[0-9]+\.b, p[0-9]+/z, p[0-9]+\.b\n} 1 { xfail *-*-* } } } */ -+/* { dg-final { scan-assembler-not {\tbic\t} } } */ -+/* { dg-final { scan-assembler-times {\tnot\tp[0-9]+\.b, p[0-9]+/z, p[0-9]+\.b\n} 1 } } */ - /* { dg-final { scan-assembler-times {\tfcmgt\tp[0-9]+\.d, p[0-9]+/z, z[0-9]+\.d, #0} 1 } } */ -diff --git a/gcc/testsuite/gcc.target/aarch64/sve/pred-not-gen-4.c b/gcc/testsuite/gcc.target/aarch64/sve/pred-not-gen-4.c -index 20cbd7550b7e..1845bd3f0f70 100644 ---- a/gcc/testsuite/gcc.target/aarch64/sve/pred-not-gen-4.c -+++ b/gcc/testsuite/gcc.target/aarch64/sve/pred-not-gen-4.c -@@ -8,6 +8,6 @@ void f13(double * restrict z, double * restrict w, double * restrict x, double * - } - } - --/* { dg-final { scan-assembler-not {\tbic\t} { xfail *-*-* } } } */ --/* { dg-final { scan-assembler-times {\tnot\tp[0-9]+\.b, p[0-9]+/z, p[0-9]+\.b\n} 1 { xfail *-*-* } } } */ -+/* { dg-final { scan-assembler-not {\tbic\t} } } */ -+/* { dg-final { scan-assembler-times {\tnot\tp[0-9]+\.b, p[0-9]+/z, p[0-9]+\.b\n} 1 } } */ - /* { dg-final { scan-assembler-times {\tfcmuo\tp[0-9]+\.d, p[0-9]+/z, z[0-9]+\.d, z[0-9]+\.d} 1 } } */ -diff --git a/gcc/testsuite/gcc.target/aarch64/sve/var_stride_2.c b/gcc/testsuite/gcc.target/aarch64/sve/var_stride_2.c -index 33b9f0f197e4..b8afea70207f 100644 ---- a/gcc/testsuite/gcc.target/aarch64/sve/var_stride_2.c -+++ b/gcc/testsuite/gcc.target/aarch64/sve/var_stride_2.c -@@ -16,7 +16,8 @@ f (TYPE *x, TYPE *y, unsigned short n, unsigned short m) - /* { dg-final { scan-assembler {\tldr\tw[0-9]+} } } */ - /* { dg-final { scan-assembler {\tstr\tw[0-9]+} } } */ - /* Should multiply by (257-1)*4 rather than (VF-1)*4 or (VF-2)*4. */ --/* { dg-final { scan-assembler-times {\tadd\tx[0-9]+, x[0-9]+, x[0-9]+, lsl 10\n} 2 } } */ -+/* { dg-final { scan-assembler-times {\tubfiz\tx[0-9]+, x2, 10, 16\n} 1 } } */ -+/* { dg-final { scan-assembler-times {\tubfiz\tx[0-9]+, x3, 10, 16\n} 1 } } */ - /* { dg-final { scan-assembler-not {\tcmp\tx[0-9]+, 0} } } */ - /* { dg-final { scan-assembler-not {\tcmp\tw[0-9]+, 0} } } */ - /* { dg-final { scan-assembler-not {\tcsel\tx[0-9]+} } } */ -diff --git a/gcc/testsuite/gcc.target/aarch64/sve/var_stride_4.c b/gcc/testsuite/gcc.target/aarch64/sve/var_stride_4.c -index 71b826a4c1bb..d2e74f9d4175 100644 ---- a/gcc/testsuite/gcc.target/aarch64/sve/var_stride_4.c -+++ b/gcc/testsuite/gcc.target/aarch64/sve/var_stride_4.c -@@ -16,7 +16,8 @@ f (TYPE *x, TYPE *y, int n, int m) - /* { dg-final { scan-assembler {\tldr\tw[0-9]+} } } */ - /* { dg-final { scan-assembler {\tstr\tw[0-9]+} } } */ - /* Should multiply by (257-1)*4 rather than (VF-1)*4. */ --/* { dg-final { scan-assembler-times {\t(?:lsl\tx[0-9]+, x[0-9]+, 10|sbfiz\tx[0-9]+, x[0-9]+, 10, 32)\n} 2 } } */ -+/* { dg-final { scan-assembler-times {\tsbfiz\tx[0-9]+, x2, 10, 32\n} 1 } } */ -+/* { dg-final { scan-assembler-times {\tsbfiz\tx[0-9]+, x3, 10, 32\n} 1 } } */ - /* { dg-final { scan-assembler {\tcmp\tw2, 0} } } */ - /* { dg-final { scan-assembler {\tcmp\tw3, 0} } } */ - /* { dg-final { scan-assembler-times {\tcsel\tx[0-9]+} 4 } } */ - -base-commit: d25728c98682c058bfda79333c94b0a8cf2a3f49 --- -2.49.0 - diff --git a/15.0.0/gentoo/84_all_combine-Avoid-split_i2i3-search-if-i2-is-unchanged-P.patch b/15.0.0/gentoo/84_all_combine-Avoid-split_i2i3-search-if-i2-is-unchanged-P.patch deleted file mode 100644 index 19d4917..0000000 --- a/15.0.0/gentoo/84_all_combine-Avoid-split_i2i3-search-if-i2-is-unchanged-P.patch +++ /dev/null @@ -1,54 +0,0 @@ -https://inbox.sourceware.org/gcc-patches/[email protected]/ - -From fac8faddc3fca52b6d51c0d1a57323012a1fe4e9 Mon Sep 17 00:00:00 2001 -Message-ID: <fac8faddc3fca52b6d51c0d1a57323012a1fe4e9.1743793443.git....@gentoo.org> -In-Reply-To: <de2f5e9c4ce4bb674fb0da191102838a6bdd92f6.1743793443.git....@gentoo.org> -References: <de2f5e9c4ce4bb674fb0da191102838a6bdd92f6.1743793443.git....@gentoo.org> -From: Richard Sandiford <[email protected]> -Date: Fri, 4 Apr 2025 10:22:12 +0100 -Subject: [PATCH 2/4] combine: Avoid split_i2i3 search if i2 is unchanged - [PR116398] - -When combining a single-set i2 into a multi-set i3, combine -first tries to match the new multi-set in-place. If that fails, -combine considers splitting the multi-set so that one set goes in -i2 and the other set stays in i3. That moves a destination from i3 -to i2 and so combine needs to update any associated log link for that -destination to point to i2 rather than i3. - -However, that kind of split can also occur for 2->2 combinations. -For a 2-instruction combination in which i2 doesn't die in i3, combine -tries a 2->1 combination by turning i3 into a parallel of the original -i2 and the combined i3. If that fails, combine will split the parallel -as above, so that the first set goes in i2 and the second set goes in i3. -But that can often leave i2 unchanged, meaning that no destinations have -moved and so no search is necessary. - -gcc/ - PR testsuite/116398 - * combine.cc (try_combine): Shortcut the split_i2i3 handling if - i2 is unchanged. ---- - gcc/combine.cc | 6 ++++++ - 1 file changed, 6 insertions(+) - -diff --git a/gcc/combine.cc b/gcc/combine.cc -index 65a87a45b3be..e29cff7147d9 100644 ---- a/gcc/combine.cc -+++ b/gcc/combine.cc -@@ -4212,6 +4212,12 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0, - - bool only_i3_changed = !i0 && !i1 && rtx_equal_p (newi2pat, PATTERN (i2)); - -+ /* If only i3 has changed, any split of the combined instruction just -+ restored i2 to its original state. No destinations moved from i3 -+ to i2. */ -+ if (only_i3_changed) -+ split_i2i3 = false; -+ - /* We now know that we can do this combination. Merge the insns and - update the status of registers and LOG_LINKS. */ - --- -2.49.0 - diff --git a/15.0.0/gentoo/85_all_combine-Optimise-distribute_links-search-PR116398.patch b/15.0.0/gentoo/85_all_combine-Optimise-distribute_links-search-PR116398.patch deleted file mode 100644 index f8849ba..0000000 --- a/15.0.0/gentoo/85_all_combine-Optimise-distribute_links-search-PR116398.patch +++ /dev/null @@ -1,99 +0,0 @@ -https://inbox.sourceware.org/gcc-patches/[email protected]/ - -From bc27a2f371602bf897ff4da1620a56eeeeebf8ff Mon Sep 17 00:00:00 2001 -Message-ID: <bc27a2f371602bf897ff4da1620a56eeeeebf8ff.1743793443.git....@gentoo.org> -In-Reply-To: <de2f5e9c4ce4bb674fb0da191102838a6bdd92f6.1743793443.git....@gentoo.org> -References: <de2f5e9c4ce4bb674fb0da191102838a6bdd92f6.1743793443.git....@gentoo.org> -From: Richard Sandiford <[email protected]> -Date: Fri, 4 Apr 2025 10:22:32 +0100 -Subject: [PATCH 3/4] combine: Optimise distribute_links search [PR116398] - -Another problem in PR101523 was that, after each successful 2->2 -combination attempt, distribute_links would search further and further -for the next combinable use of the i2 destination. Each search would -start at i2 itself, making the search quadratic in the worst case. - -In a 2->2 combination, if i2 is unchanged, the search can start at i3 -instead of i2. The same thing applies to i2 when distributing i2's -links, since the only changes to earlier instructions are the deletion -of i0 and i1. - -This change, combined with the previous split_i2i3 patch, gives a -34.6% speedup in combine for the testcase in PR101523. Combine -goes from being 41% to 34% of compile time. - -gcc/ - PR testsuite/116398 - * combine.cc (distribute_links): Take an optional start point. - (try_combine): If only i3 has changed, only distribute i3's links, - not i2's. Start the search for the new use from i3 rather than - from the definition instruction. Likewise start the search for - the new use from i2 when distributing i2's links. ---- - gcc/combine.cc | 27 +++++++++++++++++++-------- - 1 file changed, 19 insertions(+), 8 deletions(-) - -diff --git a/gcc/combine.cc b/gcc/combine.cc -index e29cff7147d9..e99b064c98d4 100644 ---- a/gcc/combine.cc -+++ b/gcc/combine.cc -@@ -472,7 +472,7 @@ static void move_deaths (rtx, rtx, int, rtx_insn *, rtx *); - static bool reg_bitfield_target_p (rtx, rtx); - static void distribute_notes (rtx, rtx_insn *, rtx_insn *, rtx_insn *, - rtx, rtx, rtx); --static void distribute_links (struct insn_link *); -+static void distribute_links (struct insn_link *, rtx_insn * = nullptr); - static void mark_used_regs_combine (rtx); - static void record_promoted_value (rtx_insn *, rtx); - static bool unmentioned_reg_p (rtx, rtx); -@@ -4592,10 +4592,15 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0, - NULL_RTX, NULL_RTX, NULL_RTX); - } - -- distribute_links (i3links); -- distribute_links (i2links); -- distribute_links (i1links); -- distribute_links (i0links); -+ if (only_i3_changed) -+ distribute_links (i3links, i3); -+ else -+ { -+ distribute_links (i3links); -+ distribute_links (i2links, i2); -+ distribute_links (i1links); -+ distribute_links (i0links); -+ } - - if (REG_P (i2dest)) - { -@@ -14986,10 +14991,13 @@ distribute_notes (rtx notes, rtx_insn *from_insn, rtx_insn *i3, rtx_insn *i2, - - /* Similarly to above, distribute the LOG_LINKS that used to be present on - I3, I2, and I1 to new locations. This is also called to add a link -- pointing at I3 when I3's destination is changed. */ -+ pointing at I3 when I3's destination is changed. -+ -+ If START is nonnull and an insn, we know that the next location for each -+ link is no earlier than START. */ - - static void --distribute_links (struct insn_link *links) -+distribute_links (struct insn_link *links, rtx_insn *start) - { - struct insn_link *link, *next_link; - -@@ -15055,7 +15063,10 @@ distribute_links (struct insn_link *links) - I3 to I2. Also note that not much searching is typically done here - since most links don't point very far away. */ - -- for (insn = NEXT_INSN (link->insn); -+ insn = start; -+ if (!insn || NOTE_P (insn)) -+ insn = NEXT_INSN (link->insn); -+ for (; - (insn && (this_basic_block->next_bb == EXIT_BLOCK_PTR_FOR_FN (cfun) - || BB_HEAD (this_basic_block->next_bb) != insn)); - insn = NEXT_INSN (insn)) --- -2.49.0 - diff --git a/15.0.0/gentoo/86_all_combine-Limit-insn-searchs-for-2-2-combinations-PR11.patch b/15.0.0/gentoo/86_all_combine-Limit-insn-searchs-for-2-2-combinations-PR11.patch deleted file mode 100644 index b185cba..0000000 --- a/15.0.0/gentoo/86_all_combine-Limit-insn-searchs-for-2-2-combinations-PR11.patch +++ /dev/null @@ -1,240 +0,0 @@ -https://inbox.sourceware.org/gcc-patches/[email protected]/ - -From 247ac81832821bade9fa36c350d220dca039d383 Mon Sep 17 00:00:00 2001 -Message-ID: <247ac81832821bade9fa36c350d220dca039d383.1743793443.git....@gentoo.org> -In-Reply-To: <de2f5e9c4ce4bb674fb0da191102838a6bdd92f6.1743793443.git....@gentoo.org> -References: <de2f5e9c4ce4bb674fb0da191102838a6bdd92f6.1743793443.git....@gentoo.org> -From: Richard Sandiford <[email protected]> -Date: Fri, 4 Apr 2025 10:23:00 +0100 -Subject: [PATCH 4/4] combine: Limit insn searchs for 2->2 combinations - [PR116398] - -As noted in the previous patch, combine still takes >30% of -compile time in the original testcase for PR101523. The problem -is that try_combine uses linear insn searches for some dataflow -queries, so in the worst case, an unlimited number of 2->2 -combinations for the same i2 can lead to quadratic behaviour. - -This patch limits distribute_links to a certain number -of instructions when i2 is unchanged. As Segher said in the PR trail, -it would make more conceptual sense to apply the limit unconditionally, -but I thought it would be better to change as little as possible at -this development stage. Logically, in stage 1, the --param should -be applied directly by distribute_links with no input from callers. - -As I mentioned in: - - https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116398#c28 - -I think it's safe to drop log links even if a use exists. All -processing of log links seems to handle the absence of a link -for a particular register in a conservative way. - -The initial set-up errs on the side of dropping links, since for example -create_log_links has: - - /* flow.c claimed: - - We don't build a LOG_LINK for hard registers contained - in ASM_OPERANDs. If these registers get replaced, - we might wind up changing the semantics of the insn, - even if reload can make what appear to be valid - assignments later. */ - if (regno < FIRST_PSEUDO_REGISTER - && asm_noperands (PATTERN (use_insn)) >= 0) - continue; - -which excludes combinations by dropping log links, rather than during -try_combine. And: - - /* If this register is being initialized using itself, and the - register is uninitialized in this basic block, and there are - no LOG_LINKS which set the register, then part of the - register is uninitialized. In that case we can't assume - anything about the number of nonzero bits. - - ??? We could do better if we checked this in - reg_{nonzero_bits,num_sign_bit_copies}_for_combine. Then we - could avoid making assumptions about the insn which initially - sets the register, while still using the information in other - insns. We would have to be careful to check every insn - involved in the combination. */ - - if (insn - && reg_referenced_p (x, PATTERN (insn)) - && !REGNO_REG_SET_P (DF_LR_IN (BLOCK_FOR_INSN (insn)), - REGNO (x))) - { - struct insn_link *link; - - FOR_EACH_LOG_LINK (link, insn) - if (dead_or_set_p (link->insn, x)) - break; - if (!link) - { - rsp->nonzero_bits = GET_MODE_MASK (mode); - rsp->sign_bit_copies = 1; - return; - } - } - -treats the lack of a log link as a possible sign of uninitialised data, -but that would be a missed optimisation rather than a correctness issue. - -One question is what the default --param value should be. I went with -Jakub's suggestion of 3000 from: - - https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116398#c25 - -Also, to answer Jakub's question in that comment, I tried bisecting: - - int limit = atoi (getenv ("BISECT")); - -(so applying the limit for all calls from try_combine) with an -abort in distribute_links if the limit caused a link to be skipped. -The minimum BISECT value that allowed an aarch64-linux-gnu bootstrap -to succeed with --enable-languages=all --enable-checking=yes,rtl,extra -was 142, so much lower than the parameter value. I realised too late -that --enable-checking=release would probably have been a more -interesting test. - -The previous patch meant that distribute_links itself is now linear -for a given i2 definition, since each search starts at the previous -last use, rather than at i2 itself. This means that the limit has -to be applied cumulatively across all searches for the same link. - -The patch does that by storing a counter in the insn_link structure. -There was a 32-bit hole there on LP64 hosts. - -gcc/ - PR testsuite/116398 - * params.opt (-param=max-combine-search-insns=): New param. - * doc/invoke.texi: Document it. - * combine.cc (insn_link::insn_count): New field. - (alloc_insn_link): Initialize it. - (distribute_links): Add a limit parameter. - (try_combine): Use the new param to limit distribute_links - when only i3 has changed. ---- - gcc/combine.cc | 21 +++++++++++++++++---- - gcc/doc/invoke.texi | 9 +++++++++ - gcc/params.opt | 4 ++++ - 3 files changed, 30 insertions(+), 4 deletions(-) - -diff --git a/gcc/combine.cc b/gcc/combine.cc -index e99b064c98d4..5f085187cfef 100644 ---- a/gcc/combine.cc -+++ b/gcc/combine.cc -@@ -309,6 +309,7 @@ static int *uid_insn_cost; - struct insn_link { - rtx_insn *insn; - unsigned int regno; -+ int insn_count; - struct insn_link *next; - }; - -@@ -342,6 +343,7 @@ alloc_insn_link (rtx_insn *insn, unsigned int regno, struct insn_link *next) - sizeof (struct insn_link)); - l->insn = insn; - l->regno = regno; -+ l->insn_count = 0; - l->next = next; - return l; - } -@@ -472,7 +474,8 @@ static void move_deaths (rtx, rtx, int, rtx_insn *, rtx *); - static bool reg_bitfield_target_p (rtx, rtx); - static void distribute_notes (rtx, rtx_insn *, rtx_insn *, rtx_insn *, - rtx, rtx, rtx); --static void distribute_links (struct insn_link *, rtx_insn * = nullptr); -+static void distribute_links (struct insn_link *, rtx_insn * = nullptr, -+ int limit = INT_MAX); - static void mark_used_regs_combine (rtx); - static void record_promoted_value (rtx_insn *, rtx); - static bool unmentioned_reg_p (rtx, rtx); -@@ -4593,7 +4596,7 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0, - } - - if (only_i3_changed) -- distribute_links (i3links, i3); -+ distribute_links (i3links, i3, param_max_combine_search_insns); - else - { - distribute_links (i3links); -@@ -14994,10 +14997,12 @@ distribute_notes (rtx notes, rtx_insn *from_insn, rtx_insn *i3, rtx_insn *i2, - pointing at I3 when I3's destination is changed. - - If START is nonnull and an insn, we know that the next location for each -- link is no earlier than START. */ -+ link is no earlier than START. LIMIT is the maximum number of nondebug -+ instructions that can be scanned when looking for the next use of a -+ definition. */ - - static void --distribute_links (struct insn_link *links, rtx_insn *start) -+distribute_links (struct insn_link *links, rtx_insn *start, int limit) - { - struct insn_link *link, *next_link; - -@@ -15063,9 +15068,12 @@ distribute_links (struct insn_link *links, rtx_insn *start) - I3 to I2. Also note that not much searching is typically done here - since most links don't point very far away. */ - -+ int count = 0; - insn = start; - if (!insn || NOTE_P (insn)) - insn = NEXT_INSN (link->insn); -+ else -+ count = link->insn_count; - for (; - (insn && (this_basic_block->next_bb == EXIT_BLOCK_PTR_FOR_FN (cfun) - || BB_HEAD (this_basic_block->next_bb) != insn)); -@@ -15086,6 +15094,11 @@ distribute_links (struct insn_link *links, rtx_insn *start) - } - else if (INSN_P (insn) && reg_set_p (reg, insn)) - break; -+ else if (count >= limit) -+ break; -+ else -+ count += 1; -+ link->insn_count = count; - - /* If we found a place to put the link, place it there unless there - is already a link to the same insn as LINK at that point. */ -diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi -index 4c9af429ab08..0903cd2b7f23 100644 ---- a/gcc/doc/invoke.texi -+++ b/gcc/doc/invoke.texi -@@ -16518,6 +16518,15 @@ in combiner for a pseudo register as last known value of that register. - @item max-combine-insns - The maximum number of instructions the RTL combiner tries to combine. - -+@item max-combine-search-insns -+The maximum number of instructions that the RTL combiner searches in order -+to find the next use of a given register definition. If this limit is reached -+without finding such a use, the combiner will stop trying to optimize the -+definition. -+ -+Currently this limit only applies after certain successful combination -+attempts, but it could be extended to other cases in future. -+ - @item integer-share-limit - Small integer constants can use a shared data structure, reducing the - compiler's memory usage and increasing its speed. This sets the maximum -diff --git a/gcc/params.opt b/gcc/params.opt -index 4f4eb4d7a2a5..422d082b3557 100644 ---- a/gcc/params.opt -+++ b/gcc/params.opt -@@ -477,6 +477,10 @@ The maximum number of instructions to consider to unroll in a loop on average. - Common Joined UInteger Var(param_max_combine_insns) Init(4) IntegerRange(2, 4) Param Optimization - The maximum number of insns combine tries to combine. - -+-param=max-combine-search-insns= -+Common Joined UInteger Var(param_max_combine_search_insns) Init(3000) Param Optimization -+The maximum number of instructions that combine searches in order to find the next use of a particular register. -+ - -param=max-completely-peel-loop-nest-depth= - Common Joined UInteger Var(param_max_unroll_iterations) Init(8) Param Optimization - The maximum depth of a loop nest we completely peel. --- -2.49.0 - diff --git a/15.0.0/gentoo/87_all_simplify-rtx-Fix-shortcut-for-vector-eq-ne.patch b/15.0.0/gentoo/87_all_simplify-rtx-Fix-shortcut-for-vector-eq-ne.patch deleted file mode 100644 index 76c3552..0000000 --- a/15.0.0/gentoo/87_all_simplify-rtx-Fix-shortcut-for-vector-eq-ne.patch +++ /dev/null @@ -1,131 +0,0 @@ -https://inbox.sourceware.org/gcc-patches/[email protected]/ - -From 5cc0c07a938202390b612f4e47934c09a17cad9a Mon Sep 17 00:00:00 2001 -Message-ID: <5cc0c07a938202390b612f4e47934c09a17cad9a.1743817315.git....@gentoo.org> -From: Richard Sandiford <[email protected]> -Date: Tue, 1 Apr 2025 13:16:32 +0100 -Subject: [PATCH] simplify-rtx: Fix shortcut for vector eq/ne - -This patch forestalls a regression in gcc.dg/rtl/x86_64/vector_eq.c -with the patch for PR116398. The test wants: - - (cinsn 3 (set (reg:V4SI <0>) (const_vector:V4SI [(const_int 0) (const_int 0) (const_int 0) (const_int 0)]))) - (cinsn 5 (set (reg:V4SI <2>) - (eq:V4SI (reg:V4SI <0>) (reg:V4SI <1>)))) - -to be folded to a vector of -1s. One unusual thing about the fold -is that the <1> in the second insn is uninitialised; it looks like -it should be replaced by <0>, or that there should be an insn 4 that -copies <0> to <1>. - -As it stands, the test relies on init-regs to insert a zero -initialisation of <1>. This happens after all the cse/pre/fwprop -stuff, with only dce passes between init-regs and combine. -Combine therefore sees: - -(insn 3 2 8 2 (set (reg:V4SI 98) - (const_vector:V4SI [ - (const_int 0 [0]) repeated x4 - ])) 2403 {movv4si_internal} - (nil)) -(insn 8 3 9 2 (clobber (reg:V4SI 99)) -1 - (nil)) -(insn 9 8 5 2 (set (reg:V4SI 99) - (const_vector:V4SI [ - (const_int 0 [0]) repeated x4 - ])) -1 - (nil)) -(insn 5 9 7 2 (set (reg:V4SI 100) - (eq:V4SI (reg:V4SI 98) - (reg:V4SI 99))) 7874 {*sse2_eqv4si3} - (expr_list:REG_DEAD (reg:V4SI 99) - (expr_list:REG_DEAD (reg:V4SI 98) - (expr_list:REG_EQUAL (eq:V4SI (const_vector:V4SI [ - (const_int 0 [0]) repeated x4 - ]) - (reg:V4SI 99)) - (nil))))) - -It looks like the test should then pass through a 3, 9 -> 5 combination, -so that we get an (eq ...) between two zeros and fold it to a vector -of -1s. But although the combination is attempted, the fold doesn't -happen. Instead, combine is left to match the unsimplified (eq ...) -between two zeros, which rightly fails. The test only passes because -late_combine2 happens to try simplifying an (eq ...) between reg X and -reg X, which does fold to a vector of -1s. - -The different handling of registers and constants is due to this -code in simplify_const_relational_operation: - - if (INTEGRAL_MODE_P (mode) && trueop1 != const0_rtx - && (code == EQ || code == NE) - && ! ((REG_P (op0) || CONST_INT_P (trueop0)) - && (REG_P (op1) || CONST_INT_P (trueop1))) - && (tem = simplify_binary_operation (MINUS, mode, op0, op1)) != 0 - /* We cannot do this if tem is a nonzero address. */ - && ! nonzero_address_p (tem)) - return simplify_const_relational_operation (signed_condition (code), - mode, tem, const0_rtx); - -INTEGRAL_MODE_P matches vector integer modes, but everything else -about the condition is written for scalar integers only. Thus if -trueop0 and trueop1 are equal vector constants, we'll bypass all -the exclusions and try simplifying a subtraction. This will succeed, -giving a vector of zeros. The recursive call will then try to simplify -a comparison between the vector of zeros and const0_rtx, which isn't -well-formed. Luckily or unluckily, the ill-formedness doesn't trigger -an ICE, but it does prevent any simplification from happening. - -The least-effort fix would be to replace INTEGRAL_MODE_P with -SCALAR_INT_MODE_P. But the fold does make conceptual sense for -vectors too, so it seemed better to keep the INTEGRAL_MODE_P and -generalise the rest of the condition to match. - -Tested on aarch64-linux-gnu & x86_64-linux-gnu. OK to install? - -I'm hoping to post the actual patch for PR116398 later today. - -Richard - -gcc/ - * simplify-rtx.cc (simplify_const_relational_operation): Generalize - the constant checks in the fold-via-minus path to match the - INTEGRAL_MODE_P condition. ---- - gcc/simplify-rtx.cc | 13 +++++++++---- - 1 file changed, 9 insertions(+), 4 deletions(-) - -diff --git a/gcc/simplify-rtx.cc b/gcc/simplify-rtx.cc -index fe007bc7d96a..6f969effdf99 100644 ---- a/gcc/simplify-rtx.cc -+++ b/gcc/simplify-rtx.cc -@@ -6657,15 +6657,20 @@ simplify_const_relational_operation (enum rtx_code code, - we do not know the signedness of the operation on either the left or - the right hand side of the comparison. */ - -- if (INTEGRAL_MODE_P (mode) && trueop1 != const0_rtx -+ if (INTEGRAL_MODE_P (mode) -+ && trueop1 != CONST0_RTX (mode) - && (code == EQ || code == NE) -- && ! ((REG_P (op0) || CONST_INT_P (trueop0)) -- && (REG_P (op1) || CONST_INT_P (trueop1))) -+ && ! ((REG_P (op0) -+ || CONST_SCALAR_INT_P (trueop0) -+ || CONST_VECTOR_P (trueop0)) -+ && (REG_P (op1) -+ || CONST_SCALAR_INT_P (trueop1) -+ || CONST_VECTOR_P (trueop1))) - && (tem = simplify_binary_operation (MINUS, mode, op0, op1)) != 0 - /* We cannot do this if tem is a nonzero address. */ - && ! nonzero_address_p (tem)) - return simplify_const_relational_operation (signed_condition (code), -- mode, tem, const0_rtx); -+ mode, tem, CONST0_RTX (mode)); - - if (! HONOR_NANS (mode) && code == ORDERED) - return const_true_rtx; - -base-commit: 2f62e66e1444d858e937faa7147f6cd06296b33b --- -2.49.0 - diff --git a/15.0.0/gentoo/README.history b/15.0.0/gentoo/README.history index 20d64c4..51cd6a7 100644 --- a/15.0.0/gentoo/README.history +++ b/15.0.0/gentoo/README.history @@ -1,5 +1,10 @@ 54 ???? + - 83_all_combine-Allow-2-2-combinations-but-with-a-tweak-PR11.patch + - 84_all_combine-Avoid-split_i2i3-search-if-i2-is-unchanged-P.patch + - 85_all_combine-Optimise-distribute_links-search-PR116398.patch + - 86_all_combine-Limit-insn-searchs-for-2-2-combinations-PR11.patch + - 87_all_simplify-rtx-Fix-shortcut-for-vector-eq-ne.patch U 88_all_PR119614.patch 53 7 April 2025
