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Re: S/390: Fix warnings in "*setmem_long..." patterns.
- From: Andreas Krebbel <krebbel at linux dot vnet dot ibm dot com>
- To: gcc-patches at gcc dot gnu dot org, Ulrich Weigand <Ulrich dot Weigand at de dot ibm dot com>
- Date: Mon, 30 Nov 2015 17:06:50 +0100
- Subject: Re: S/390: Fix warnings in "*setmem_long..." patterns.
- Authentication-results: sourceware.org; auth=none
- References: <20151130151120 dot GA25255 at linux dot vnet dot ibm dot com>
On 11/30/2015 04:11 PM, Dominik Vogt wrote:
> The attached patch fixes some warnings generated by the setmem...
> patterns in s390.md during build and add test cases for the
> patterns. The patch is to be added on to p of the movstr patch:
> https://gcc.gnu.org/ml/gcc-patches/2015-11/msg03485.html
>
> The test cases validate that the patterns are actually used, but
> at the moment the setmem_long_and pattern is never actually used
> and thus the test case would fail. So I've split the patch in two
> (both attached to this message) to activate this part of the test
> once we've fixed that.
>
> The patch has passed the SPEC2006 testsuite without any measurable
> changes in performance.
Shouldn't we instead describe the whole setmem operation as unspec including the other operands as
well? The semantics of the introduced UNSPEC_P_TO_BLK operation is not clear to me. It suggests to
be some kind of "cast" which it isn't. In fact it is not able to do its job without the length which
is specified as use outside the unspec.
Bye,
-Andreas-