public inbox for gcc-cvs@sourceware.org help / color / mirror / Atom feed
From: Florian Weimer <fw@gcc.gnu.org> To: gcc-cvs@gcc.gnu.org Subject: [gcc r13-3326] libgcc: Move cfa_how into potential padding in struct frame_state_reg_info Date: Mon, 17 Oct 2022 09:20:18 +0000 (GMT) [thread overview] Message-ID: <20221017092018.E27853858D28@sourceware.org> (raw) https://gcc.gnu.org/g:acdb24166d13d87c374e578d2ad5d58249171930 commit r13-3326-gacdb24166d13d87c374e578d2ad5d58249171930 Author: Florian Weimer <fweimer@redhat.com> Date: Mon Oct 17 11:09:17 2022 +0200 libgcc: Move cfa_how into potential padding in struct frame_state_reg_info On many architectures, there is a padding gap after the how array member, and cfa_how can be moved there. This reduces the size of the struct and the amount of memory that uw_frame_state_for has to clear. There is no measurable performance benefit from this on x86-64 (even though the memset goes from 120 to 112 bytes), but it seems to be a good idea to do anyway. libgcc/ * unwind-dw2.h (struct frame_state_reg_info): Move cfa_how member and reduce its size. Diff: --- libgcc/unwind-dw2.h | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/libgcc/unwind-dw2.h b/libgcc/unwind-dw2.h index af34e000f07..a0834b18277 100644 --- a/libgcc/unwind-dw2.h +++ b/libgcc/unwind-dw2.h @@ -50,6 +50,12 @@ typedef struct } reg[__LIBGCC_DWARF_FRAME_REGISTERS__+1]; unsigned char how[__LIBGCC_DWARF_FRAME_REGISTERS__+1]; + enum { + CFA_UNSET, + CFA_REG_OFFSET, + CFA_EXP + } cfa_how : 8; + /* Used to implement DW_CFA_remember_state. */ struct frame_state_reg_info *prev; @@ -58,11 +64,6 @@ typedef struct _Unwind_Sword cfa_offset; _Unwind_Word cfa_reg; const unsigned char *cfa_exp; - enum { - CFA_UNSET, - CFA_REG_OFFSET, - CFA_EXP - } cfa_how; } regs; /* The PC described by the current frame state. */
reply other threads:[~2022-10-17 9:20 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=20221017092018.E27853858D28@sourceware.org \ --to=fw@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).