RE: [PATCH] Relax check against commuting XOR and ASHIFTRT in combine.c

[Alan Lawrence <alan.lawrence@arm.com>]

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Mmmm, I've made a few attempts at filtering according to LP64 and ILP32, but not 
managed to get anything working so far (that is, I've ended up with the test not 
being executed on platforms where it should)....ah, I see now where I've been 
going wrong, patch attached.

The original intent was pretty much to execute the test on everything with the 
appropriate word size, i.e. where a 64-bit comparison would be done in 64 bits 
rather than emulated in 2*32; and for 32-bit where that was not sign-extended to 
64 (or some other such problem). The architectures I wrote in the file, were 
those on which I tested the rtl dump, excluding some archs where you get (neg 
(lt 0 x)) rather than (neg (ge x 0)); but the latter really shouldn't be a 
problem, it should be possible to use a regex matching either form, and then 
drop the target selection.

However, as a quick first step, does adding the ilp32 / lp64 (and keeping the 
architectures list for now) solve the immediate problem? Patch attached, OK for 
trunk?

gcc/testsuite/ChangeLog:

	* gcc.dg/combine_ashiftrt_1.c: require-effective-target LP64
	* gcc.dg/combine_ashiftrt_2.c: require-effective-target ILP32

--Alan
________________________________________
From: Rainer Orth [ro@cebitec.uni-bielefeld.de]
Sent: 23 October 2014 14:10
To: Andreas Schwab
Cc: Alan Lawrence; Jeff Law; gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] Relax check against commuting XOR and ASHIFTRT in combine.c

Andreas Schwab <schwab@linux-m68k.org> writes:

> Alan Lawrence <alan.lawrence@arm.com> writes:
>
>> diff --git a/gcc/testsuite/gcc.dg/combine_ashiftrt_1.c
>> b/gcc/testsuite/gcc.dg/combine_ashiftrt_1.c
>> new file mode 100644
>> index
>> 0000000000000000000000000000000000000000..90e64fd10dc358f10ad03a90041605bc3ccb7011
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/combine_ashiftrt_1.c
>> @@ -0,0 +1,18 @@
>> +/* { dg-do compile {target sparc64*-*-* aarch64*-*-* x86_64-*-*
>> powerpc64*-*-*} } */
>
> You should check for lp64 instead of matching 64 in target names, to
> reject -m32.
>
>> diff --git a/gcc/testsuite/gcc.dg/combine_ashiftrt_2.c
>> b/gcc/testsuite/gcc.dg/combine_ashiftrt_2.c
>> new file mode 100644
>> index
>> 0000000000000000000000000000000000000000..fd6827caed230ea5dd2d6ec4431b11bf826531ea
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/combine_ashiftrt_2.c
>> @@ -0,0 +1,18 @@
>> +/* { dg-do compile {target arm*-*-* i?86-*-* powerpc-*-* sparc-*-*} } */
>
> Likewise, using ilp32 to reject -m64.

Right, the current target lists are simply bogus on biarch targets.

Alan, what's the reasoning behind your current target lists here?  Any
reason the test couldn't work elsewhere?  If not, it would be way better
to introduce a corresponding effective-target keyword than listing
particular targets without explanation.

This needs to be fixed: the issue is knowns for three weeks now and
causes testsuite noise on many platforms.

         Rainer

--
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Rainer Orth, Center for Biotechnology, Bielefeld University

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commit 43e8585f475dff386d245cb150940755cd9b43d9
Author: Alan Lawrence <alan.lawrence@arm.com>
Date:   Thu Oct 23 17:41:28 2014 +0100

    Add ILP32 / LP64

diff --git a/gcc/testsuite/gcc.dg/combine_ashiftrt_1.c b/gcc/testsuite/gcc.dg/combine_ashiftrt_1.c
index 90e64fd..cb669c9 100644
--- a/gcc/testsuite/gcc.dg/combine_ashiftrt_1.c
+++ b/gcc/testsuite/gcc.dg/combine_ashiftrt_1.c
@@ -1,4 +1,5 @@
 /* { dg-do compile {target sparc64*-*-* aarch64*-*-* x86_64-*-* powerpc64*-*-*} } */
+/* { dg-require-effective-target lp64 } */
 /* { dg-options "-O2 -fdump-rtl-combine-all" } */
 
 typedef long long int int64_t;
diff --git a/gcc/testsuite/gcc.dg/combine_ashiftrt_2.c b/gcc/testsuite/gcc.dg/combine_ashiftrt_2.c
index fd6827c..6bd6f2f 100644
--- a/gcc/testsuite/gcc.dg/combine_ashiftrt_2.c
+++ b/gcc/testsuite/gcc.dg/combine_ashiftrt_2.c
@@ -1,4 +1,5 @@
 /* { dg-do compile {target arm*-*-* i?86-*-* powerpc-*-* sparc-*-*} } */
+/* { dg-require-effective-target ilp32} */
 /* { dg-options "-O2 -fdump-rtl-combine-all" } */
 
 typedef long int32_t;