From: <apinski@marvell.com>
To: <gcc-patches@gcc.gnu.org>
Cc: Andrew Pinski <apinski@marvell.com>
Subject: [PATCH] Fix middle-end/103645: empty struct store not removed when using compound literal
Date: Sun, 7 Aug 2022 20:37:06 -0700 [thread overview]
Message-ID: <1659929826-10136-1-git-send-email-apinski@marvell.com> (raw)
From: Andrew Pinski <apinski@marvell.com>
For compound literals empty struct stores are not removed as they go down a
different path of the gimplifier; trying to optimize the init constructor.
This fixes the problem by not adding the gimple assignment at the end
of gimplify_init_constructor if it was an empty type.
Note this updates gcc.dg/pr87052.c where we had:
const char d[0] = { };
And was expecting a store to d but after this, there is no store
as the decl's type is zero in size.
OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
gcc/ChangeLog:
PR middle-end/103645
* gimplify.c (gimplify_init_constructor): Don't build/add
gimple assignment of an empty type.
testsuite/ChangeLog:
* gcc.dg/pr87052.c: Update d var to expect nothing.
---
gcc/gimplify.cc | 7 +++++--
gcc/testsuite/gcc.dg/pr87052.c | 6 +++---
2 files changed, 8 insertions(+), 5 deletions(-)
diff --git a/gcc/gimplify.cc b/gcc/gimplify.cc
index 2ac7ca0855e..f0fbdb48012 100644
--- a/gcc/gimplify.cc
+++ b/gcc/gimplify.cc
@@ -5488,8 +5488,11 @@ gimplify_init_constructor (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p,
if (ret == GS_ERROR)
return GS_ERROR;
/* If we have gimplified both sides of the initializer but have
- not emitted an assignment, do so now. */
- if (*expr_p)
+ not emitted an assignment, do so now. */
+ if (*expr_p
+ /* If the type is an empty type, we don't need to emit the
+ assignment. */
+ && !is_empty_type (TREE_TYPE (TREE_OPERAND (*expr_p, 0))))
{
tree lhs = TREE_OPERAND (*expr_p, 0);
tree rhs = TREE_OPERAND (*expr_p, 1);
diff --git a/gcc/testsuite/gcc.dg/pr87052.c b/gcc/testsuite/gcc.dg/pr87052.c
index 18e092c4674..796fe6440c1 100644
--- a/gcc/testsuite/gcc.dg/pr87052.c
+++ b/gcc/testsuite/gcc.dg/pr87052.c
@@ -23,8 +23,7 @@ void test (void)
const char d[0] = { };
- /* Expect the following:
- d = ""; */
+ /* Expect nothing. */
const char e[0] = "";
@@ -36,6 +35,7 @@ void test (void)
/* { dg-final { scan-tree-dump-times "a = \"\\\\x00ab\";" 1 "gimple" } }
{ dg-final { scan-tree-dump-times "b = \"a\\\\x00bc\";" 1 "gimple" } }
{ dg-final { scan-tree-dump-times "c = \"\";" 1 "gimple" } }
- { dg-final { scan-tree-dump-times "d = { *};" 1 "gimple" } }
+ { dg-final { scan-tree-dump-times "d = " 1 "gimple" } }
+ { dg-final { scan-tree-dump-times "d = {CLOBBER\\(eol\\)}" 1 "gimple" } }
{ dg-final { scan-tree-dump-times "e = " 1 "gimple" } }
{ dg-final { scan-tree-dump-times "e = {CLOBBER\\(eol\\)}" 1 "gimple" } } */
--
2.27.0
next reply other threads:[~2022-08-08 3:37 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-08 3:37 apinski [this message]
2022-08-08 7:59 ` Richard Biener
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=1659929826-10136-1-git-send-email-apinski@marvell.com \
--to=apinski@marvell.com \
--cc=gcc-patches@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: link
Be 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).