public inbox for gcc-cvs@sourceware.org help / color / mirror / Atom feed
From: Jakub Jelinek <jakub@gcc.gnu.org> To: gcc-cvs@gcc.gnu.org Subject: [gcc r11-9498] ifcvt: Check for asm goto at the end of then_bb/else_bb in ifcvt [PR103908] Date: Mon, 24 Jan 2022 09:21:07 +0000 (GMT) [thread overview] Message-ID: <20220124092107.64C22385840D@sourceware.org> (raw) https://gcc.gnu.org/g:0dd533da49cf15aa9afd35634ba4bd80e9c96565 commit r11-9498-g0dd533da49cf15aa9afd35634ba4bd80e9c96565 Author: Jakub Jelinek <jakub@redhat.com> Date: Thu Jan 6 09:29:34 2022 +0100 ifcvt: Check for asm goto at the end of then_bb/else_bb in ifcvt [PR103908] On the following testcase, RTL ifcvt sees then_bb (note 7 6 8 3 [bb 3] NOTE_INSN_BASIC_BLOCK) (insn 8 7 9 3 (set (mem/c:SI (symbol_ref:DI ("b") [flags 0x2] <var_decl 0x7fdccf5b0cf0 b>) [1 b+0 S4 A32]) (const_int 1 [0x1])) "pr103908.c":6:7 81 {*movsi_internal} (nil)) (jump_insn 9 8 13 3 (parallel [ (asm_operands/v ("# insn 1") ("") 0 [] [] [ (label_ref:DI 21) ] pr103908.c:7) (clobber (reg:CC 17 flags)) ]) "pr103908.c":7:5 -1 (expr_list:REG_UNUSED (reg:CC 17 flags) (nil)) -> 21) and similarly else_bb (just with a different asm_operands template). It checks that those basic blocks have a single successor and uses last_active_insn which intentionally skips over JUMP_INSNs, sees both basic blocks contain the same set and merges them (or if the sets are different, attempts some other noce optimization). But we can't assume that the jump, even when it has only a single successor, has no side-effects. The following patch fixes it by punting if test_bb ends with a JUMP_INSN that isn't onlyjump_p. 2022-01-06 Jakub Jelinek <jakub@redhat.com> PR rtl-optimization/103908 * ifcvt.c (bb_valid_for_noce_process_p): Punt on bbs ending with asm goto. * gcc.target/i386/pr103908.c: New test. (cherry picked from commit 80ad67e2af0620d58d57d0406dc22693cf5b8ca9) Diff: --- gcc/ifcvt.c | 6 ++++++ gcc/testsuite/gcc.target/i386/pr103908.c | 24 ++++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c index 1ac0c160266..2d98cc2a35a 100644 --- a/gcc/ifcvt.c +++ b/gcc/ifcvt.c @@ -3064,6 +3064,12 @@ bb_valid_for_noce_process_p (basic_block test_bb, rtx cond, if (!insn_valid_noce_process_p (last_insn, cc)) return false; + + /* Punt on blocks ending with asm goto or jumps with other side-effects, + last_active_insn ignores JUMP_INSNs. */ + if (JUMP_P (BB_END (test_bb)) && !onlyjump_p (BB_END (test_bb))) + return false; + last_set = single_set (last_insn); rtx x = SET_DEST (last_set); diff --git a/gcc/testsuite/gcc.target/i386/pr103908.c b/gcc/testsuite/gcc.target/i386/pr103908.c new file mode 100644 index 00000000000..7c57e1ddf6a --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr103908.c @@ -0,0 +1,24 @@ +/* PR rtl-optimization/103908 */ +/* { dg-do compile } */ +/* { dg-options "-O1 -fdisable-tree-cselim -fno-tree-sink" } */ +/* { dg-final { scan-assembler "# insn 1" } } */ +/* { dg-final { scan-assembler "# insn 2" } } */ + +int a, b; + +void +foo (void) +{ + if (a) + { + b = 1; + asm goto ("# insn 1" : : : : lab1); + lab1:; + } + else + { + b = 1; + asm goto ("# insn 2" : : : : lab2); + lab2:; + } +}
reply other threads:[~2022-01-24 9:21 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=20220124092107.64C22385840D@sourceware.org \ --to=jakub@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).