public inbox for gcc-cvs@sourceware.org help / color / mirror / Atom feed
From: Richard Biener <rguenth@gcc.gnu.org> To: gcc-cvs@gcc.gnu.org Subject: [gcc r11-9657] debug/104337 - avoid messing with the abstract origin chain in NRV Date: Wed, 16 Mar 2022 08:22:12 +0000 (GMT) [thread overview] Message-ID: <20220316082212.DAFE2385ED40@sourceware.org> (raw) https://gcc.gnu.org/g:24ec11aec20fd621a74c4a3bc7d61aaddf8ef8c8 commit r11-9657-g24ec11aec20fd621a74c4a3bc7d61aaddf8ef8c8 Author: Richard Biener <rguenther@suse.de> Date: Thu Feb 3 11:20:59 2022 +0100 debug/104337 - avoid messing with the abstract origin chain in NRV The following avoids NRV from massaging DECL_ABSTRACT_ORIGIN after variable creation since NRV runs _after_ the function was inlined and thus affects the inlined variables copy indirectly. We may adjust the abstract origin of a variable only at the point we create it, not further along the path since otherwise the (new) invariant that the abstract origin is always the ultimate origin cannot be maintained. The intent of what NRV does is OK I guess and it may improve the debug experience. But I also notice we do SET_DECL_VALUE_EXPR (found, result); DECL_HAS_VALUE_EXPR_P (found) = 1; the code is there since the merge from tree-ssa which added tree-nrv.c. Jakub added the DECL_VALUE_EXPR in g:938650d8fddb878f623e315f0b7fd94b217efa96 and Jason added the abstract origin setting conditional in g:7716876bbd3a The follwoing takes the radical approach and remove the attempt to "optimize" the debug info. The gdb testsuites show no regressions. 2022-02-03 Richard Biener <rguenther@suse.de> PR debug/104337 * tree-nrv.c (pass_nrv::execute): Remove tieing result and found together via DECL_ABSTRACT_ORIGIN. * gcc.dg/debug/pr104337.c: New testcase. (cherry picked from commit 1d5c7584fd6e72bfdbede86cef5ff04ae35f9744) Diff: --- gcc/testsuite/gcc.dg/debug/pr104337.c | 15 +++++++++++++++ gcc/tree-nrv.c | 13 ------------- 2 files changed, 15 insertions(+), 13 deletions(-) diff --git a/gcc/testsuite/gcc.dg/debug/pr104337.c b/gcc/testsuite/gcc.dg/debug/pr104337.c new file mode 100644 index 00000000000..d15680fbf1a --- /dev/null +++ b/gcc/testsuite/gcc.dg/debug/pr104337.c @@ -0,0 +1,15 @@ +/* { dg-do compile } */ + +struct a { + unsigned b : 7; +}; +inline __attribute__((optimize(3))) __attribute__((always_inline)) struct a +c() { + struct a d; + return d; +} +void e() { + for (;;) + c(); +} +int main() {} diff --git a/gcc/tree-nrv.c b/gcc/tree-nrv.c index bcfa6bfa1d5..9602a640628 100644 --- a/gcc/tree-nrv.c +++ b/gcc/tree-nrv.c @@ -236,19 +236,6 @@ pass_nrv::execute (function *fun) fprintf (dump_file, "\n"); } - /* At this point we know that all the return statements return the - same local which has suitable attributes for NRV. Copy debugging - information from FOUND to RESULT if it will be useful. But don't set - DECL_ABSTRACT_ORIGIN to point at another function. */ - if (!DECL_IGNORED_P (found) - && !(DECL_ABSTRACT_ORIGIN (found) - && DECL_CONTEXT (DECL_ABSTRACT_ORIGIN (found)) != current_function_decl)) - { - DECL_NAME (result) = DECL_NAME (found); - DECL_SOURCE_LOCATION (result) = DECL_SOURCE_LOCATION (found); - DECL_ABSTRACT_ORIGIN (result) = DECL_ABSTRACT_ORIGIN (found); - } - TREE_ADDRESSABLE (result) |= TREE_ADDRESSABLE (found); /* Now walk through the function changing all references to VAR to be
reply other threads:[~2022-03-16 8:22 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=20220316082212.DAFE2385ED40@sourceware.org \ --to=rguenth@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).