public inbox for gcc-cvs@sourceware.org help / color / mirror / Atom feed
From: Roger Sayle <sayle@gcc.gnu.org> To: gcc-cvs@gcc.gnu.org Subject: [gcc r12-8542] PR target/106122: Don't update %esp via the stack with -Oz on x86. Date: Sun, 3 Jul 2022 13:02:25 +0000 (GMT) [thread overview] Message-ID: <20220703130225.CA71F3851154@sourceware.org> (raw) https://gcc.gnu.org/g:55899e33de74082521708a58fdc79510e0c5efad commit r12-8542-g55899e33de74082521708a58fdc79510e0c5efad Author: Roger Sayle <roger@nextmovesoftware.com> Date: Sun Jul 3 14:01:17 2022 +0100 PR target/106122: Don't update %esp via the stack with -Oz on x86. When optimizing for size with -Oz, setting a register can be minimized by pushing an immediate value to the stack and popping it to the destination. Alas the one general register that shouldn't be updated via the stack is the stack pointer itself, where "pop %esp" can't be represented in GCC's RTL ("use of a register mentioned in pre_inc, pre_dec, post_inc or post_dec is not permitted within the same instruction"). This patch fixes PR target/106122 by explicitly checking for SP_REG in the problematic peephole2. 2022-07-O3 Roger Sayle <roger@nextmovesoftware.com> gcc/ChangeLog PR target/106122 * config/i386/i386.md (peephole2): Avoid generating pop %esp when optimizing for size. gcc/testsuite/ChangeLog PR target/106122 * gcc.target/i386/pr106122.c: New test case. Diff: --- gcc/config/i386/i386.md | 3 ++- gcc/testsuite/gcc.target/i386/pr106122.c | 15 +++++++++++++++ 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md index c74edd1aaef..7c9560fc4f0 100644 --- a/gcc/config/i386/i386.md +++ b/gcc/config/i386/i386.md @@ -2519,7 +2519,8 @@ "optimize_insn_for_size_p () && optimize_size > 1 && operands[1] != const0_rtx && IN_RANGE (INTVAL (operands[1]), -128, 127) - && !ix86_red_zone_used" + && !ix86_red_zone_used + && REGNO (operands[0]) != SP_REG" [(set (match_dup 2) (match_dup 1)) (set (match_dup 0) (match_dup 3))] { diff --git a/gcc/testsuite/gcc.target/i386/pr106122.c b/gcc/testsuite/gcc.target/i386/pr106122.c new file mode 100644 index 00000000000..7d24ed3376d --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr106122.c @@ -0,0 +1,15 @@ +/* PR middle-end/106122 */ +/* { dg-do compile } */ +/* { dg-options "-Oz" } */ + +register volatile int a __asm__("%esp"); +void foo (void *); +void bar (void *); + +void +baz (void) +{ + foo (__builtin_return_address (0)); + a = 0; + bar (__builtin_return_address (0)); +}
reply other threads:[~2022-07-03 13:02 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=20220703130225.CA71F3851154@sourceware.org \ --to=sayle@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).