On Wed, Mar 18, 2015 at 5:22 AM, Alan Modra <amo...@gmail.com> wrote: > On Tue, Mar 17, 2015 at 01:28:41PM -0600, Jeff Law wrote: >> On 03/14/2015 07:02 AM, Alan Modra wrote: >> > PR target/65408 >> > PR target/58744 >> > PR middle-end/36043 >> > * calls.c (load_register_parameters): Don't load past end of >> > mem unless suitably aligned. >> I think this is probably a stage1 item. Richi, Jakub, Joseph, do any of you >> think we should try to push this into gcc-5? > > Some (severity) background to PR65408. The bug came from SAP HANA > (en.wikipedia.org/wiki/SAP_HANA), a crash that happens on powerpc64 > and powerpc64le. aarch64 would also be susceptible to the crash since > it also loads 16 bytes for the 12-byte struct. x86_64 only loads 12 > bytes (i386.c:construct_container generates a parallel with a DImode > and SImode load). However the underlying bug is there and hits x86_64 > too for the pr58744 and pr36043 testcases..
It's a very very very old bug though. I'd be interested in any odd code-generation difference for compiling, say, the linux kernel (you _can_ get quite ugly code generated because of this fix). I'm leaning towards waiting for stage1 and then consider a backport to 5.1. I'm sure the HAHA guys can work-around by forcing an extra temporary on the stack and passing that. Richard. > -- > Alan Modra > Australia Development Lab, IBM
