From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by sourceware.org (Postfix) with ESMTP id 120CF385772C for ; Thu, 7 Dec 2023 01:40:29 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 120CF385772C Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=loongson.cn ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 120CF385772C Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=114.242.206.163 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1701913233; cv=none; b=WocBEGW8Xuv2q4AALUhHDSHLt0I7nC/j9K19NsmMGJ8qblQ4k0JGU3c2DCOyxOZPIvLeVJEGCBjwEdKe6FS50YuOueeC7CTjr6BNGALk1ZVrFoC0ehhg4rBuy2wI1Cv6gajXK26gipC6gh55fNEcoNx5p7HUmd32m5afy0bAxI8= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1701913233; c=relaxed/simple; bh=EK32GUXY5NRddnUhkZ7jzI38Br0ntJx2r90frxsH/tA=; h=From:To:Subject:Date:Message-ID:MIME-Version; b=rviwkAUHrKaPi0opdXZpC3MQkuZ0omlNBxqRdiuwLr8KAaeNWXakKJlwVlSIVZGgaiNG2o38VujWmQapJ3ZlSGv4Ke8xbKqOEzulOFxLJcJB074m7jVquopxoaZyHv/SnhHhRROeMCUum+iGNshQrRP7vwXKBY8unpYEnc56ELk= ARC-Authentication-Results: i=1; server2.sourceware.org Received: from loongson.cn (unknown [114.243.111.185]) by gateway (Coremail) with SMTP id _____8Cx7+uJInFlDH8_AA--.60377S3; Thu, 07 Dec 2023 09:40:25 +0800 (CST) Received: from localhost.localdomain (unknown [114.243.111.185]) by localhost.localdomain (Coremail) with SMTP id AQAAf8Axrt6FInFleg5XAA--.9857S3; Thu, 07 Dec 2023 09:40:22 +0800 (CST) From: Yang Yujie To: gcc-patches@gcc.gnu.org Cc: chenglulu@loongson.cn, xuchenghua@loongson.cn, Yang Yujie Subject: [PATCH v3] LoongArch: Fix eh_return epilogue for normal returns Date: Thu, 7 Dec 2023 09:40:11 +0800 Message-ID: <20231207014011.1512-2-yangyujie@loongson.cn> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231207014011.1512-1-yangyujie@loongson.cn> References: <20231207014011.1512-1-yangyujie@loongson.cn> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:AQAAf8Axrt6FInFleg5XAA--.9857S3 X-CM-SenderInfo: 51dqw5pxmlvqxorr0wxvrqhubq/1tbiAQASAGVv2iwMSgAAsp X-Coremail-Antispam: 1Uk129KBj93XoW3XryrKw4kAr4xGFy5GFW8KrX_yoWxtw18pr ZrZr93Ar48Jwnxtr1DJ345XFn5ArZ2gr1av3W3tryxCw47Zr9rZFn7tF9FqF1ktw48ur1I qF4kJa1Yv3WUG3cCm3ZEXasCq-sJn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUkjb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Gr0_Xr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_ Gr0_Gr1UM2AIxVAIcxkEcVAq07x20xvEncxIr21l57IF6xkI12xvs2x26I8E6xACxx1l5I 8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r126r1DMcIj6I8E87Iv67AK xVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41l42xK82IYc2Ij64 vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8G jcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r126r1DMIIYrxkI7VAKI48JMIIF0xvE2I x0cI8IcVAFwI0_JFI_Gr1lIxAIcVC0I7IYx2IY6xkF7I0E14v26r1j6r4UMIIF0xvE42xK 8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I 0E14v26r1j6r4UYxBIdaVFxhVjvjDU0xZFpf9x07UMpBfUUUUU= X-Spam-Status: No, score=-10.5 required=5.0 tests=BAYES_00,GIT_PATCH_0,KAM_DMARC_STATUS,KAM_SHORT,RCVD_IN_BARRACUDACENTRAL,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On LoongArch, the regitsters $r4 - $r7 (EH_RETURN_DATA_REGNO) will be saved and restored in the function prologue and epilogue if the given function calls __builtin_eh_return. This causes the return value to be overwritten on normal return paths and breaks a rare case of libgcc's _Unwind_RaiseException. gcc/ChangeLog: * config/loongarch/loongarch.cc: Do not restore the saved eh_return data registers ($r4-$r7) for a normal return of a function that calls __builtin_eh_return elsewhere. * config/loongarch/loongarch-protos.h: Same. * config/loongarch/loongarch.md: Same. gcc/testsuite/ChangeLog: * gcc.target/loongarch/eh_return-normal-return.c: New test. --- gcc/config/loongarch/loongarch-protos.h | 2 +- gcc/config/loongarch/loongarch.cc | 41 ++++++++++++------- gcc/config/loongarch/loongarch.md | 18 +++++++- .../loongarch/eh_return-normal-return.c | 32 +++++++++++++++ 4 files changed, 76 insertions(+), 17 deletions(-) create mode 100644 gcc/testsuite/gcc.target/loongarch/eh_return-normal-return.c diff --git a/gcc/config/loongarch/loongarch-protos.h b/gcc/config/loongarch/loongarch-protos.h index cb8fc36b086..af20b5d7132 100644 --- a/gcc/config/loongarch/loongarch-protos.h +++ b/gcc/config/loongarch/loongarch-protos.h @@ -60,7 +60,7 @@ enum loongarch_symbol_type { extern rtx loongarch_emit_move (rtx, rtx); extern HOST_WIDE_INT loongarch_initial_elimination_offset (int, int); extern void loongarch_expand_prologue (void); -extern void loongarch_expand_epilogue (bool); +extern void loongarch_expand_epilogue (int); extern bool loongarch_can_use_return_insn (void); extern bool loongarch_symbolic_constant_p (rtx, enum loongarch_symbol_type *); diff --git a/gcc/config/loongarch/loongarch.cc b/gcc/config/loongarch/loongarch.cc index 3545e66a10e..9c0e0dd1b73 100644 --- a/gcc/config/loongarch/loongarch.cc +++ b/gcc/config/loongarch/loongarch.cc @@ -1015,20 +1015,30 @@ loongarch_save_restore_reg (machine_mode mode, int regno, HOST_WIDE_INT offset, static void loongarch_for_each_saved_reg (HOST_WIDE_INT sp_offset, - loongarch_save_restore_fn fn) + loongarch_save_restore_fn fn, + bool skip_eh_data_regs_p) { HOST_WIDE_INT offset; /* Save the link register and s-registers. */ offset = cfun->machine->frame.gp_sp_offset - sp_offset; for (int regno = GP_REG_FIRST; regno <= GP_REG_LAST; regno++) - if (BITSET_P (cfun->machine->frame.mask, regno - GP_REG_FIRST)) - { - if (!cfun->machine->reg_is_wrapped_separately[regno]) - loongarch_save_restore_reg (word_mode, regno, offset, fn); + { + /* Special care needs to be taken for $r4-$r7 (EH_RETURN_DATA_REGNO) + when returning normally from a function that calls __builtin_eh_return. + In this case, these registers are saved but should not be restored, + or the return value may be clobbered. */ - offset -= UNITS_PER_WORD; - } + if (BITSET_P (cfun->machine->frame.mask, regno - GP_REG_FIRST)) + { + if (!(cfun->machine->reg_is_wrapped_separately[regno] + || (skip_eh_data_regs_p + && GP_ARG_FIRST <= regno && regno < GP_ARG_FIRST + 4))) + loongarch_save_restore_reg (word_mode, regno, offset, fn); + + offset -= UNITS_PER_WORD; + } + } /* This loop must iterate over the same space as its companion in loongarch_compute_frame_info. */ @@ -1297,7 +1307,7 @@ loongarch_expand_prologue (void) GEN_INT (-step1)); RTX_FRAME_RELATED_P (emit_insn (insn)) = 1; size -= step1; - loongarch_for_each_saved_reg (size, loongarch_save_reg); + loongarch_for_each_saved_reg (size, loongarch_save_reg, false); } /* Set up the frame pointer, if we're using one. */ @@ -1382,11 +1392,11 @@ loongarch_can_use_return_insn (void) return reload_completed && cfun->machine->frame.total_size == 0; } -/* Expand an "epilogue" or "sibcall_epilogue" pattern; SIBCALL_P - says which. */ +/* Expand function epilogue for the following insn patterns: + "epilogue" (style == 0) / "sibcall_epilogue" (1) / "eh_return" (2). */ void -loongarch_expand_epilogue (bool sibcall_p) +loongarch_expand_epilogue (int style) { /* Split the frame into two. STEP1 is the amount of stack we should deallocate before restoring the registers. STEP2 is the amount we @@ -1403,7 +1413,8 @@ loongarch_expand_epilogue (bool sibcall_p) bool need_barrier_p = (get_frame_size () + cfun->machine->frame.arg_pointer_offset) != 0; - if (!sibcall_p && loongarch_can_use_return_insn ()) + /* Handle simple returns. */ + if (style == 0 && loongarch_can_use_return_insn ()) { emit_jump_insn (gen_return ()); return; @@ -1479,7 +1490,8 @@ loongarch_expand_epilogue (bool sibcall_p) /* Restore the registers. */ loongarch_for_each_saved_reg (frame->total_size - step2, - loongarch_restore_reg); + loongarch_restore_reg, + crtl->calls_eh_return && style != 2); if (need_barrier_p) loongarch_emit_stack_tie (); @@ -1504,7 +1516,8 @@ loongarch_expand_epilogue (bool sibcall_p) emit_insn (gen_add3_insn (stack_pointer_rtx, stack_pointer_rtx, EH_RETURN_STACKADJ_RTX)); - if (!sibcall_p) + /* Emit return unless doing sibcall. */ + if (style != 1) emit_jump_insn (gen_simple_return_internal (ra)); } diff --git a/gcc/config/loongarch/loongarch.md b/gcc/config/loongarch/loongarch.md index 7a101dd64b7..61b27293489 100644 --- a/gcc/config/loongarch/loongarch.md +++ b/gcc/config/loongarch/loongarch.md @@ -3197,7 +3197,7 @@ (define_expand "epilogue" [(const_int 2)] "" { - loongarch_expand_epilogue (false); + loongarch_expand_epilogue (0); DONE; }) @@ -3205,7 +3205,7 @@ (define_expand "sibcall_epilogue" [(const_int 2)] "" { - loongarch_expand_epilogue (true); + loongarch_expand_epilogue (1); DONE; }) @@ -3262,6 +3262,20 @@ (define_expand "eh_return" emit_insn (gen_eh_set_ra_di (operands[0])); else emit_insn (gen_eh_set_ra_si (operands[0])); + + emit_jump_insn (gen_eh_return_internal ()); + emit_barrier (); + DONE; +}) + +(define_insn_and_split "eh_return_internal" + [(eh_return)] + "" + "#" + "epilogue_completed" + [(const_int 0)] +{ + loongarch_expand_epilogue (2); DONE; }) diff --git a/gcc/testsuite/gcc.target/loongarch/eh_return-normal-return.c b/gcc/testsuite/gcc.target/loongarch/eh_return-normal-return.c new file mode 100644 index 00000000000..da7e98a35bd --- /dev/null +++ b/gcc/testsuite/gcc.target/loongarch/eh_return-normal-return.c @@ -0,0 +1,32 @@ +/* { dg-do run } */ +/* { dg-options "-O2" } */ + +#include + +int foo () __attribute__((noinline)); +int main (); + +int +foo () { + + int t; + + /* prevent optimization using asm */ + asm ("" : "=r" (t) : "0" (-1)); + asm ("" : "=r" (t) : "0" (t ? 1 : 0)); + + if (t == 0) + /* never reached */ + __builtin_eh_return (0, __builtin_return_address (0)); + else + return 202312; +} + +int +main () +{ + if (foo() == 202312) + return 0; + else + abort (); +} -- 2.43.0