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Re: [PING*2][PATCH] Extend mode-switching to support toggle (1/2)
- From: Oleg Endo <oleg dot endo at t-online dot de>
- To: Joern Rennecke <joern dot rennecke at embecosm dot com>
- Cc: Christian Bruel <christian dot bruel at st dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>, Jeff Law <law at redhat dot com>, Kaz Kojima <kkojima at rr dot iij4u dot or dot jp>
- Date: Tue, 13 May 2014 00:39:12 +0200
- Subject: Re: [PING*2][PATCH] Extend mode-switching to support toggle (1/2)
- Authentication-results: sourceware.org; auth=none
- References: <535E0C86 dot 400 at st dot com> <537089D8 dot 8040106 at st dot com> <53708F1D dot 1080308 at st dot com> <CAMqJFCpxG2RyOZ0NsYiBV5PUU4A+8kWaq22am+GR=e22i-uf0g at mail dot gmail dot com> <5370BB9D dot 1090803 at st dot com> <CAMqJFCovAjbuJK6puakdUZu-mDdUdWS92exwLdz3fKGO+goMZA at mail dot gmail dot com>
On Mon, 2014-05-12 at 13:51 +0100, Joern Rennecke wrote:
> On 12 May 2014 13:16, Christian Bruel <firstname.lastname@example.org> wrote:
> > Just for my curiosity, which other targets have multi-way toggling
> > support ?
> The epiphany has, sort of: you read a control register, AND and/or OR
> some mask(s) to the value,
> and write it back.
> If we knew the previous mode, we might elide and AND or an OR.
> I think this is actually quite a common issue.
This is the same as changing/setting the FP modes (PR, SZ) on SH while
preserving the other FPSCR bits, or did I miss something?