Re: [RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses, take 2

This is a small follow-up change that I had meant to commit for a while (ahem); done now. Thanks for taking the time to write this up! Gerald Index: changes.html === RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-4.7/changes.html,v retrievin

Ping again: [RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses, take 2

> From: Hans-Peter Nilsson > Date: Fri, 29 Jun 2012 15:06:44 +0200 > > From: Hans-Peter Nilsson > > Date: Fri, 22 Jun 2012 04:24:01 +0200 > > > > From: Hans-Peter Nilsson > > > Date: Fri, 15 Jun 2012 04:07:23 +0200 > > > > A ping. > > And another ping, now CCing ARM maintainers, >

Re: Ping: [RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses, take 2

> From: Hans-Peter Nilsson > Date: Fri, 22 Jun 2012 04:24:01 +0200 > > From: Hans-Peter Nilsson > > Date: Fri, 15 Jun 2012 04:07:23 +0200 > > A ping. And another ping, now CCing ARM maintainers, . > > Y is 28 for introduction of the quo

Ping: [RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses, take 2

> From: Hans-Peter Nilsson > Date: Fri, 15 Jun 2012 04:07:23 +0200 A ping. > Y is 28 for introduction of the quoted code in > arch/arm/mm/alignment.c, AFAICT, so how about this one, ok now? > > Index: changes.html > === > RCS file:

[RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses, take 2

Y is 28 for introduction of the quoted code in arch/arm/mm/alignment.c, AFAICT, so how about this one, ok now? Index: changes.html === RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-4.7/changes.html,v retrieving revision 1.113 diff -p -u -r1.1

Re: [RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses

> From: Hans-Peter Nilsson > Date: Mon, 11 Jun 2012 01:16:09 +0200 > +to be compiled with -mno-unaligned-accesses. Better spelled as "-mno-unaligned-access". Bah. brgds, H-P

Re: [RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses

> From: Michael Hope > Date: Wed, 13 Jun 2012 00:43:47 +0200 > On 13 June 2012 02:32, Hans-Peter Nilsson wrote: > >> From: Hans-Peter Nilsson > >> Date: Mon, 11 Jun 2012 00:59:57 +0200 > >> > > user-space code".  Maybe the kernel too, I can't say; there was > >> > > IIRC no sign of it. > > But

Re: [RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses

On 13 June 2012 02:32, Hans-Peter Nilsson wrote: >> From: Hans-Peter Nilsson >> Date: Mon, 11 Jun 2012 00:59:57 +0200 > >> > From: Michael Hope >> > Date: Mon, 11 Jun 2012 00:04:19 +0200 >> >> > On 8 June 2012 16:53, Hans-Peter Nilsson >> > wrote: >> > >> From: Hans-Peter Nilsson >> > >> Date

Re: [RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses

> From: Hans-Peter Nilsson > Date: Mon, 11 Jun 2012 00:59:57 +0200 > > From: Michael Hope > > Date: Mon, 11 Jun 2012 00:04:19 +0200 > > > On 8 June 2012 16:53, Hans-Peter Nilsson > > wrote: > > >> From: Hans-Peter Nilsson > > >> Date: Fri, 8 Jun 2012 06:29:04 +0200 > > > > > >> > From: Micha

Re: [RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses

> From: Gerald Pfeifer > Date: Mon, 11 Jun 2012 00:27:21 +0200 > This is only a review wearing my web hat; it is orthogonal to the > discussion with the ARM guys. ;-) > > On Fri, 8 Jun 2012, Hans-Peter Nilsson wrote: > > +On ARM, when compiling for ARMv6 (but not ARMv6-M), ARMv7-A, > > +

Re: [RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses

> From: Michael Hope > Date: Mon, 11 Jun 2012 00:04:19 +0200 > On 8 June 2012 16:53, Hans-Peter Nilsson wrote: > >> From: Hans-Peter Nilsson > >> Date: Fri, 8 Jun 2012 06:29:04 +0200 > > > >> > From: Michael Hope > >> > Date: Fri, 8 Jun 2012 05:50:52 +0200 > >> >  The combination of > >> > old

Re: [RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses

This is only a review wearing my web hat; it is orthogonal to the discussion with the ARM guys. ;-) On Fri, 8 Jun 2012, Hans-Peter Nilsson wrote: > +On ARM, when compiling for ARMv6 (but not ARMv6-M), ARMv7-A, > +ARMv7-R, or ARMv7-M, the default of the new option > +-munaligned-accesse

Re: [RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses

On 8 June 2012 16:53, Hans-Peter Nilsson wrote: >> From: Hans-Peter Nilsson >> Date: Fri, 8 Jun 2012 06:29:04 +0200 > >> > From: Michael Hope >> > Date: Fri, 8 Jun 2012 05:50:52 +0200 >> >  The combination of >> > older Linux ARM kernels and GCC 4.7 gives a faulty kernel. >> >> We're in agreemen

Re: [RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses

> From: Hans-Peter Nilsson > Date: Fri, 8 Jun 2012 06:29:04 +0200 > > From: Michael Hope > > Date: Fri, 8 Jun 2012 05:50:52 +0200 > > The combination of > > older Linux ARM kernels and GCC 4.7 gives a faulty kernel. > > We're in agreement! Oh wait sorry, my bad, I misread. Instead of "gives

Re: [RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses

> From: Michael Hope > Date: Fri, 8 Jun 2012 05:50:52 +0200 > On 8 June 2012 15:20, Hans-Peter Nilsson wrote: > > So the default for ALIGNMENT_TRAP changed in >3.1? > > ALIGNMENT_TRAP is on by default but the early boot time trap is now > conditional on the architecture level: > > __enable_mmu

Re: [RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses

On 8 June 2012 15:20, Hans-Peter Nilsson wrote: >> From: Michael Hope >> Date: Fri, 8 Jun 2012 04:42:30 +0200 > >> On 8 June 2012 12:15, Hans-Peter Nilsson wrote: >> > The "some source >> > codes" was in the analyzed case a strcpy of a five-byte string >> > (busybox/libbb/procps.c:365 'strcpy(fi

Re: [RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses

> From: Michael Hope > Date: Fri, 8 Jun 2012 04:42:30 +0200 > On 8 June 2012 12:15, Hans-Peter Nilsson wrote: > > The "some source > > codes" was in the analyzed case a strcpy of a five-byte string > > (busybox/libbb/procps.c:365 'strcpy(filename_tail, "stat");' of > > some unknown busybox-versi

Re: [RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses

On 8 June 2012 12:15, Hans-Peter Nilsson wrote: > (CC to ARM maintainer approving the original patch.) > > I'm listing this under "caveats" rather than "improvements" and > before the current top ARM-related caveat (as this one is more > important :) because I don't see performance figures in the

[RFA:] Caveat for ARM in gcc-4.7/changes.html: unaligned accesses

(CC to ARM maintainer approving the original patch.) I'm listing this under "caveats" rather than "improvements" and before the current top ARM-related caveat (as this one is more important :) because I don't see performance figures in the context of the original patch (r178852) backing up this as