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From: "amodra at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/65408] powerpc64 function argument passing may access invalid memory Date: Wed, 18 Mar 2015 11:07:00 -0000 [thread overview] Message-ID: <bug-65408-4-GMDB772uhQ@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-65408-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65408 --- Comment #6 from Alan Modra <amodra at gmail dot com> --- Code quality for both powerpc64le and x86_64 looks passable for the testcase here and other structs with at least one int field (ie. when the struct size is a multiple of 4, and alignment is 4). You get DImode loads followed by an SImode load if the struct isn't a multiple of 8 in size. Code quality does suffer a little for big-endian since any SImode load at the end of the struct needs to be shifted, whereas a DImode loading past the end of the struct needs no shifting. For cases where the struct size isn't a multiple of 4, code quality certainly does suffer, worst case being a struct of size 7 that would now be loaded by 7 byte loads.. Should we care more about that than a segfault in real-world user code? Hmm. Answering my own question, I guess that since pr36043 is nearly seven years old, we don't care too much about segfaults!
next prev parent reply other threads:[~2015-03-18 11:07 UTC|newest] Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <bug-65408-4@http.gcc.gnu.org/bugzilla/> 2015-03-12 17:52 ` ktkachov at gcc dot gnu.org 2015-03-13 0:42 ` amodra at gmail dot com 2015-03-13 9:27 ` rguenth at gcc dot gnu.org 2015-03-14 3:19 ` amodra at gmail dot com 2015-03-18 9:59 ` rguenth at gcc dot gnu.org 2015-03-18 11:07 ` amodra at gmail dot com [this message] 2015-04-15 7:29 ` amodra at gcc dot gnu.org 2015-04-30 7:33 ` rguenth at gcc dot gnu.org 2015-04-30 11:12 ` amodra at gcc dot gnu.org 2015-04-30 11:15 ` amodra at gmail dot com 2015-04-30 11:15 ` amodra at gmail dot com
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