From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 7924) id 32E0C3870C20; Wed, 27 Sep 2023 08:28:19 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 32E0C3870C20 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1695803299; bh=VGNo/B8rZHAHFd0eLBziSYeKDTprM9C/hhat39cjM/g=; h=From:To:Subject:Date:From; b=Qa3TrYsA3kuR5bcKhLWPDgymb+2RjA3U1+l0XahvYnfEREhlt95BqhqbnFEIJCrqh 64ptIrYmVJdpsOKLHNNxnjeQXCR28T5PmbvXBuLWaKUjYGOKo5ZaPHXpI+0S07ELjP LbPEUxjDU7JQYQwukcIoU7KwZNQ2C8oHOXEsTHCg= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Pan Li To: gcc-cvs@gcc.gnu.org Subject: [gcc r14-4291] DSE: Fix ICE when the mode with access_size don't exist on the target[PR111590] X-Act-Checkin: gcc X-Git-Author: Juzhe-Zhong X-Git-Refname: refs/heads/master X-Git-Oldrev: c00b6fef46cdc85e825538e08074f9fcbeb7bf84 X-Git-Newrev: 073849da3dfd5cabbfd4492a40a17b207b4a7630 Message-Id: <20230927082819.32E0C3870C20@sourceware.org> Date: Wed, 27 Sep 2023 08:28:19 +0000 (GMT) List-Id: https://gcc.gnu.org/g:073849da3dfd5cabbfd4492a40a17b207b4a7630 commit r14-4291-g073849da3dfd5cabbfd4492a40a17b207b4a7630 Author: Juzhe-Zhong Date: Wed Sep 27 06:47:12 2023 +0800 DSE: Fix ICE when the mode with access_size don't exist on the target[PR111590] hen doing fortran test with 'V' extension enabled on RISC-V port. I saw multiple ICE: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111590 The root cause is on DSE: internal compiler error: in smallest_mode_for_size, at stor-layout.cc:356 0x1918f70 smallest_mode_for_size(poly_int<2u, unsigned long>, mode_class) ../../../../gcc/gcc/stor-layout.cc:356 0x11f75bb smallest_int_mode_for_size(poly_int<2u, unsigned long>) ../../../../gcc/gcc/machmode.h:916 0x3304141 find_shift_sequence ../../../../gcc/gcc/dse.cc:1738 0x3304f1a get_stored_val ../../../../gcc/gcc/dse.cc:1906 0x3305377 replace_read ../../../../gcc/gcc/dse.cc:2010 0x3306226 check_mem_read_rtx ../../../../gcc/gcc/dse.cc:2310 0x330667b check_mem_read_use ../../../../gcc/gcc/dse.cc:2415 After investigations, DSE is trying to do optimization like this following codes: (insn 86 85 87 9 (set (reg:V4DI 168) (mem/u/c:V4DI (reg/f:DI 171) [0 S32 A128])) "bug.f90":6:18 discrim 6 1167 {*movv4di} (expr_list:REG_EQUAL (const_vector:V4DI [ (const_int 4 [0x4]) (const_int 1 [0x1]) repeated x2 (const_int 3 [0x3]) ]) (nil))) (set (mem) (reg:V4DI 168)) Then it ICE on: auto new_mode = smallest_int_mode_for_size (access_size * BITS_PER_UNIT); The access_size may be 24 or 32. We don't have such integer modes with these size so it ICE. TODO: The better way maybe make DSE use native_encode_rtx/native_decode_rtx but I don't know how to do that. So let's quickly fix this issue, we can improve the fix later. PR target/111590 gcc/ChangeLog: * dse.cc (find_shift_sequence): Check the mode with access_size exist on the target. Diff: --- gcc/dse.cc | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/gcc/dse.cc b/gcc/dse.cc index 8b07be17674..1a85dae1f8c 100644 --- a/gcc/dse.cc +++ b/gcc/dse.cc @@ -1733,7 +1733,8 @@ find_shift_sequence (poly_int64 access_size, /* If a constant was stored into memory, try to simplify it here, otherwise the cost of the shift might preclude this optimization e.g. at -Os, even when no actual shift will be needed. */ - if (store_info->const_rhs) + if (store_info->const_rhs + && known_le (access_size, GET_MODE_SIZE (MAX_MODE_INT))) { auto new_mode = smallest_int_mode_for_size (access_size * BITS_PER_UNIT); auto byte = subreg_lowpart_offset (new_mode, store_mode);