From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1314) id 40D3E3858D28; Tue, 27 Jun 2023 16:28:17 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 40D3E3858D28 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1687883297; bh=dCIEjaWmYAhfhDwnyRe3DOEn2Fxt8yF7AbBH/H/B/DU=; h=From:To:Subject:Date:From; b=otHS51jpOWrPpdVCVPVDojtLD8lzeb01LOTzEicG53GntrSODIK59cf2wYOD3KGNF /mJdvUvY2xZViygn6vWJZlDdsNR8GSyJLxnhiWcfQCk7VQqUjrmn6KSYL8dSzcxPHV hSclxNgwtFgAJz1NVmBiHwbkfHPPRetoGuIzNkc4= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Andrew Pinski To: gcc-cvs@gcc.gnu.org Subject: [gcc r14-2133] Mark asm goto with outputs as volatile X-Act-Checkin: gcc X-Git-Author: Andrew Pinski X-Git-Refname: refs/heads/trunk X-Git-Oldrev: 4a48a38fa99f067b8f3a3d1a5dc7a1e602db351f X-Git-Newrev: 478840a2ca491fbff44371caee4983d1e7b7b7cf Message-Id: <20230627162817.40D3E3858D28@sourceware.org> Date: Tue, 27 Jun 2023 16:28:17 +0000 (GMT) List-Id: https://gcc.gnu.org/g:478840a2ca491fbff44371caee4983d1e7b7b7cf commit r14-2133-g478840a2ca491fbff44371caee4983d1e7b7b7cf Author: Andrew Pinski Date: Mon Jun 26 17:14:06 2023 -0700 Mark asm goto with outputs as volatile The manual references asm goto as being implicitly volatile already and that was done when asm goto could not have outputs. When outputs were added to `asm goto`, only asm goto without outputs were still being marked as volatile. Now some parts of GCC decide, removing the `asm goto` is ok if the output is not used, though not updating the CFG (this happens on both the RTL level and the gimple level). Since the biggest user of `asm goto` is the Linux kernel and they expect them to be volatile (they use them to copy to/from userspace), we should just mark the inline-asm as volatile. OK? Bootstrapped and tested on x86_64-linux-gnu. PR middle-end/110420 PR middle-end/103979 PR middle-end/98619 gcc/ChangeLog: * gimplify.cc (gimplify_asm_expr): Mark asm with labels as volatile. gcc/testsuite/ChangeLog: * gcc.c-torture/compile/asmgoto-6.c: New test. Diff: --- gcc/gimplify.cc | 7 ++++++- gcc/testsuite/gcc.c-torture/compile/asmgoto-6.c | 26 +++++++++++++++++++++++++ 2 files changed, 32 insertions(+), 1 deletion(-) diff --git a/gcc/gimplify.cc b/gcc/gimplify.cc index 0e24b915b8f..36e5df050b9 100644 --- a/gcc/gimplify.cc +++ b/gcc/gimplify.cc @@ -6935,7 +6935,12 @@ gimplify_asm_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p) stmt = gimple_build_asm_vec (TREE_STRING_POINTER (ASM_STRING (expr)), inputs, outputs, clobbers, labels); - gimple_asm_set_volatile (stmt, ASM_VOLATILE_P (expr) || noutputs == 0); + /* asm is volatile if it was marked by the user as volatile or + there are no outputs or this is an asm goto. */ + gimple_asm_set_volatile (stmt, + ASM_VOLATILE_P (expr) + || noutputs == 0 + || labels); gimple_asm_set_input (stmt, ASM_INPUT_P (expr)); gimple_asm_set_inline (stmt, ASM_INLINE_P (expr)); diff --git a/gcc/testsuite/gcc.c-torture/compile/asmgoto-6.c b/gcc/testsuite/gcc.c-torture/compile/asmgoto-6.c new file mode 100644 index 00000000000..0652bd4e4e1 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/compile/asmgoto-6.c @@ -0,0 +1,26 @@ + +/* { dg-do compile } */ +/* PR middle-end/110420 */ +/* PR middle-end/103979 */ +/* PR middle-end/98619 */ +/* Test that the middle-end does not remove the asm goto + with an output. */ + +static int t; +void g(void); + +void f(void) +{ + int __gu_val; + asm goto("#my asm " + : "=&r"(__gu_val) + : + : + : Efault); + t = __gu_val; + g(); +Efault: +} + +/* Make sure "my asm " is still in the assembly. */ +/* { dg-final { scan-assembler "my asm " } } */