From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2153) id C6C543858014; Thu, 6 Jan 2022 08:31:12 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org C6C543858014 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Jakub Jelinek To: gcc-cvs@gcc.gnu.org Subject: [gcc r12-6278] ifcvt: Check for asm goto at the end of then_bb/else_bb in ifcvt [PR103908] X-Act-Checkin: gcc X-Git-Author: Jakub Jelinek X-Git-Refname: refs/heads/master X-Git-Oldrev: 1935db296892bbd9fc597889237528bd7e080ab1 X-Git-Newrev: 80ad67e2af0620d58d57d0406dc22693cf5b8ca9 Message-Id: <20220106083112.C6C543858014@sourceware.org> Date: Thu, 6 Jan 2022 08:31:12 +0000 (GMT) X-BeenThere: gcc-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 06 Jan 2022 08:31:12 -0000 https://gcc.gnu.org/g:80ad67e2af0620d58d57d0406dc22693cf5b8ca9 commit r12-6278-g80ad67e2af0620d58d57d0406dc22693cf5b8ca9 Author: Jakub Jelinek 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] ) [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 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. 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 539887c1831..9a3e4539fb7 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:; + } +}