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[PATCH 2/3, x86] X86 Silvermont vector cost model tune
- From: Evgeny Stupachenko <evstupac at gmail dot com>
- To: Uros Bizjak <ubizjak at gmail dot com>
- Cc: "H.J. Lu" <hjl dot tools at gmail dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>, uros at gcc dot gnu dot org
- Date: Tue, 15 Apr 2014 20:08:50 +0400
- Subject: [PATCH 2/3, x86] X86 Silvermont vector cost model tune
- Authentication-results: sourceware.org; auth=none
2d part:
2014-04-15 Evgeny Stupachenko <evstupac@gmail.com>
* config/i386/x86-tune.def (TARGET_SLOW_PHUFFB): Target for slow byte
shuffle on some x86 architectures.
* config/i386/i386.h (TARGET_SLOW_PHUFFB): Ditto.
* config/i386/i386.c (expand_vec_perm_even_odd_1): Avoid byte shuffles
in architectures where they are slow (TARGET_SLOW_PHUFFB).
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index bf4d576..0ae3cda 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -44026,7 +44026,7 @@ expand_vec_perm_even_odd_1 (struct
expand_vec_perm_d *d, unsigned odd)
gcc_unreachable ();
case V8HImode:
- if (TARGET_SSSE3)
+ if (TARGET_SSSE3 && !TARGET_SLOW_PSHUFB)
return expand_vec_perm_pshufb2 (d);
else
{
@@ -44049,7 +44049,7 @@ expand_vec_perm_even_odd_1 (struct
expand_vec_perm_d *d, unsigned odd)
break;
case V16QImode:
- if (TARGET_SSSE3)
+ if (TARGET_SSSE3 && !TARGET_SLOW_PSHUFB)
return expand_vec_perm_pshufb2 (d);
else
{
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index 51659de..1a884d8 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -425,6 +425,8 @@ extern unsigned char ix86_tune_features[X86_TUNE_LAST];
ix86_tune_features[X86_TUNE_USE_VECTOR_FP_CONVERTS]
#define TARGET_USE_VECTOR_CONVERTS \
ix86_tune_features[X86_TUNE_USE_VECTOR_CONVERTS]
+#define TARGET_SLOW_PSHUFB \
+ ix86_tune_features[X86_TUNE_SLOW_PSHUFB]
#define TARGET_FUSE_CMP_AND_BRANCH_32 \
ix86_tune_features[X86_TUNE_FUSE_CMP_AND_BRANCH_32]
#define TARGET_FUSE_CMP_AND_BRANCH_64 \
diff --git a/gcc/config/i386/x86-tune.def b/gcc/config/i386/x86-tune.def
index 8399102..9b0ff36 100644
--- a/gcc/config/i386/x86-tune.def
+++ b/gcc/config/i386/x86-tune.def
@@ -386,6 +386,10 @@ DEF_TUNE (X86_TUNE_USE_VECTOR_FP_CONVERTS,
"use_vector_fp_converts",
from integer to FP. */
DEF_TUNE (X86_TUNE_USE_VECTOR_CONVERTS, "use_vector_converts", m_AMDFAM10)
+/* X86_TUNE_SLOW_SHUFB: Indicates tunings with slow pshufb instruction. */
+DEF_TUNE (X86_TUNE_SLOW_PSHUFB, "slow_pshufb",
+ m_BONNELL | m_SILVERMONT | m_INTEL)
+
/*****************************************************************************/
/* AVX instruction selection tuning (some of SSE flags affects AVX, too) */
/*****************************************************************************/
On Thu, Mar 6, 2014 at 12:58 AM, Evgeny Stupachenko <evstupac@gmail.com> wrote:
> slm_cost/intel_cost and TARGET_SLOW_PSHUFB are just preparation to a
> next vectorization patch.
> Changes in ix86_add_stmt_cost gives real performance to Silvermont.
> Let's move all to stage1.
>
> On Wed, Mar 5, 2014 at 9:29 PM, Uros Bizjak <ubizjak@gmail.com> wrote:
>> On Wed, Mar 5, 2014 at 5:46 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>>> On Wed, Mar 5, 2014 at 7:58 AM, Evgeny Stupachenko <evstupac@gmail.com> wrote:
>>>> Hi,
>>>>
>>>> The patch is for x86 Silvermont.
>>>> It improves x86 Silvermont vector cost model.
>>>> It gives +20% on facerec spec on Silvermont.
>>>> It passes make check and bootstrap on x86.
>>>>
>>>> Is this patch ok for stage1?
>>>>
>>>> ChangeLog:
>>>>
>>>> 2014-03-05 Evgeny Stupachenko <evstupac@gmail.com>
>>>>
>>>> * config/i386/x86-tune.def (TARGET_SLOW_PSHUFB): Target for slow byte
>>>> shuffle on some x86 architectures.
>>>> * config/i386/i386.h (TARGET_SLOW_PSHUFB): Ditto.
>>>> * config/i386/i386.c (processor_costs): Fixing vec_to_scalar_cost for
>>>> Silvermont according latency table.
>>>> (expand_vec_perm_even_odd_1): Avoid byte shuffles in architectures
>>>> where they are slow (TARGET_SLOW_PSHUFB).
>>>> (x86_add_stmt_cost): Fixing vector cost model for Silvermont.
>>>>
>>>> Thanks,
>>>> Evgeny
>>>
>>> There are 3 separate changes in this patch:
>>>
>>> 1. Update slm_cost, which doesn't have a ChangeLog entry.
>>> 2. Add TARGET_SLOW_PSHUFB.
>>> 3. Update ix86_add_stmt_cost.
>>>
>>> I suggest you break it into 3 independent patches.
>>
>> I think that slm_cost/intel_cost and TARGET_SLOW_PSHUFB changes can
>> still go into mainline at this stage since they are trivial tuning
>> changes that should not destabilize the compiler.
>>
>> The ix86_add_stmt_cost should wait for stage 1.
>>
>> Uros.