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Re: [PATCH, i386] Fix emitting of prefetch instructions
- From: Uros Bizjak <ubizjak at gmail dot com>
- To: Rainer Orth <ro at cebitec dot uni-bielefeld dot de>
- Cc: "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>, Kirill Yukhin <kirill dot yukhin at gmail dot com>, Ilya Tocar <tocarip dot intel at gmail dot com>
- Date: Tue, 4 Mar 2014 00:31:30 +0100
- Subject: Re: [PATCH, i386] Fix emitting of prefetch instructions
- Authentication-results: sourceware.org; auth=none
- References: <CAFULd4Z+k9f1YMLZqNpWvb7XTMkk9XSKAn3FfwKAEK4pppbHBw at mail dot gmail dot com>
On Mon, Mar 3, 2014 at 11:27 PM, Uros Bizjak <ubizjak@gmail.com> wrote:
>> The new gcc.target/i386/prefetchwt1-1.c test currently FAILs on Solaris 9/x86:
>>
>> FAIL: gcc.target/i386/prefetchwt1-1.c (test for excess errors)
>> Excess errors:
>> /var/gcc/regression/trunk/9-gcc-gas/build/gcc/include/xmmintrin.h:1195:1: error:
>> inlining failed in call to always_inline '_mm_prefetch': target specific option
>> mismatch
>> /vol/gcc/src/hg/trunk/local/gcc/testsuite/gcc.target/i386/prefetchwt1-1.c:12:5:
>> error: called from here
>>
>> gcc.target/i386/prefetchwt1-1.c: output file does not exist
>> UNRESOLVED: gcc.target/i386/prefetchwt1-1.c scan-assembler [ \\t]+prefetchwt1[ \
>> \t]+
>>
>> This can be fixed by compiling with -msse2.
>
> Actually, we should take prefetch instructions out of various GCC
> target pragmas. Patterns that emit these instructions are designed to
> (depending on selected ISA) always emit the most optimal prefetch
> instruction.
>
> The patch also changes the compiler to emit prefetchwt1 only for
> _MM_HINT_T1, while for _MM_HINT_T0, it still emits prefetchw. In
> addition, the patch corrects wrong MM_HINT_T0 value.
>
> Patch was bootstrapped and tested on x86_64-pc-linux-gnu {,-m32} and
> committed to mainline SVN.
>
> 2014-03-03 Uros Bizjak <ubizjak@gmail.com>
>
> * config/i386/xmmintrin.h (enum _mm_hint) <_MM_HINT_ET0>: Correct
> hint value.
> (_mm_prefetch): Move out of GCC target("sse") pragma.
> * config/i386/prfchwintrin.h (_m_prefetchw): Move out of
> GCC target("prfchw") pragma.
> * config/i386/i386.md (prefetch): Emit prefetchwt1 only
> for locality <= 2.
> * config/i386/i386.c (ix86_option_override_internal): Enable
> -mprfchw with -mprefetchwt1.
BTW: There are a couple of new testsuite failures:
FAIL: gcc.target/i386/avx512pf-vscatterpf0dpd-1.c (test for excess errors)
UNRESOLVED: gcc.target/i386/avx512pf-vscatterpf0dpd-1.c
scan-assembler-times vscatterpf0dpd[ \\\\t]+[^\\n]*%ymm[0-9] 2
UNRESOLVED: gcc.target/i386/avx512pf-vscatterpf0dpd-1.c
scan-assembler-times vscatterpf0dpd[ \\\\t]+[^\\n]*{%k[1-7] 1
FAIL: gcc.target/i386/avx512pf-vscatterpf0dps-1.c (test for excess errors)
UNRESOLVED: gcc.target/i386/avx512pf-vscatterpf0dps-1.c
scan-assembler-times vscatterpf0dps[ \\\\t]+[^\\n]*%zmm[0-9] 2
UNRESOLVED: gcc.target/i386/avx512pf-vscatterpf0dps-1.c
scan-assembler-times vscatterpf0dps[ \\\\t]+[^\\n]*{%k[1-7] 1
FAIL: gcc.target/i386/avx512pf-vscatterpf0qpd-1.c (test for excess errors)
UNRESOLVED: gcc.target/i386/avx512pf-vscatterpf0qpd-1.c
scan-assembler-times vscatterpf0qpd[ \\\\t]+[^\\n]*%zmm[0-9] 2
UNRESOLVED: gcc.target/i386/avx512pf-vscatterpf0qpd-1.c
scan-assembler-times vscatterpf0qpd[ \\\\t]+[^\\n]*{%k[1-7] 1
FAIL: gcc.target/i386/avx512pf-vscatterpf0qps-1.c (test for excess errors)
UNRESOLVED: gcc.target/i386/avx512pf-vscatterpf0qps-1.c
scan-assembler-times vscatterpf0qps[ \\\\t]+[^\\n]*%zmm[0-9] 2
UNRESOLVED: gcc.target/i386/avx512pf-vscatterpf0qps-1.c
scan-assembler-times vscatterpf0qps[ \\\\t]+[^\\n]*{%k[1-7] 1
They are all:
FAIL: gcc.target/i386/avx512pf-vscatterpf0dpd-1.c (test for excess errors)
Excess errors:
/ssd/uros/gcc-build/gcc/include/avx512pfintrin.h:108:3: error: the
last argument must be hint 0 or 1
They are due to _MM_HINT_ET0 fix, and probably show that the pattern
was not updated when hint constants were adjusted to 2 and 3.
Kirill, can you please look at this inconsistency?
Uros.