[PATCH, i386] Fix emitting of prefetch instructions

[Uros Bizjak]

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.