public inbox for gdb-cvs@sourceware.org help / color / mirror / Atom feed
From: Andrew Burgess <aburgess@sourceware.org> To: gdb-cvs@sourceware.org Subject: [binutils-gdb] sim/erc32: avoid dereferencing type-punned pointer warnings Date: Wed, 19 Oct 2022 13:33:03 +0000 (GMT) [thread overview] Message-ID: <20221019133303.338633858C2D@sourceware.org> (raw) https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=d0a7ca87ab208d72b2c6a9d44e30fe20c3c0542e commit d0a7ca87ab208d72b2c6a9d44e30fe20c3c0542e Author: Andrew Burgess <aburgess@redhat.com> Date: Wed Oct 12 11:45:53 2022 +0100 sim/erc32: avoid dereferencing type-punned pointer warnings When building the erc32 simulator I get a few warnings like this: /tmp/build/sim/../../src/sim/erc32/exec.c:1377:21: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] 1377 | sregs->fs[rd] = *((float32 *) & ddata[0]); | ~^~~~~~~~~~~~~~~~~~~~~~~ The type of '& ddata[0]' will be 'uint32_t *', which is what triggers the warning. This commit makes use of memcpy when performing the type-punning, which resolves the above warnings. With this change, I now see no warnings when compiling exec.c, which means that the line in Makefile.in that disables -Werror can be removed. There should be no change in behaviour after this commit. Diff: --- sim/erc32/Makefile.in | 3 --- sim/erc32/exec.c | 7 ++++--- 2 files changed, 4 insertions(+), 6 deletions(-) diff --git a/sim/erc32/Makefile.in b/sim/erc32/Makefile.in index 786ae1dcc7b..41830aab726 100644 --- a/sim/erc32/Makefile.in +++ b/sim/erc32/Makefile.in @@ -32,9 +32,6 @@ SIM_EXTRA_CLEAN = clean-sis # behaviour of UART interrupt routines ... SIM_EXTRA_CFLAGS += -DFAST_UART -I$(srcroot) -# Some modules don't build cleanly yet. -exec.o: SIM_WERROR_CFLAGS = - ## COMMON_POST_CONFIG_FRAG # `sis' doesn't need interf.o. diff --git a/sim/erc32/exec.c b/sim/erc32/exec.c index ef93692e7a2..26d48c0e46e 100644 --- a/sim/erc32/exec.c +++ b/sim/erc32/exec.c @@ -1345,7 +1345,7 @@ dispatch_instruction(struct pstate *sregs) if (mexc) { sregs->trap = TRAP_DEXC; } else { - sregs->fs[rd] = *((float32 *) & data); + memcpy (&sregs->fs[rd], &data, sizeof (sregs->fs[rd])); } break; case LDDF: @@ -1373,11 +1373,12 @@ dispatch_instruction(struct pstate *sregs) } else { rd &= 0x1E; sregs->flrd = rd; - sregs->fs[rd] = *((float32 *) & ddata[0]); + memcpy (&sregs->fs[rd], &ddata[0], sizeof (sregs->fs[rd])); #ifdef STAT sregs->nload++; /* Double load counts twice */ #endif - sregs->fs[rd + 1] = *((float32 *) & ddata[1]); + memcpy (&sregs->fs[rd + 1], &ddata[1], + sizeof (sregs->fs[rd + 1])); sregs->ltime = ebase.simtime + sregs->icnt + FLSTHOLD + sregs->hold + sregs->fhold; }
reply other threads:[~2022-10-19 13:33 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=20221019133303.338633858C2D@sourceware.org \ --to=aburgess@sourceware.org \ --cc=gdb-cvs@sourceware.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).