x86: Re-enable partial_reg_dependency and movx for Haswell

r254152 disabled partial_reg_dependency and movx for Haswell and newer
Intel processors.  r258972 restored them for skylake-avx512.  For Haswell,
movx improves performance.  But partial_reg_stall may be better than
partial_reg_dependency in theory.  We will investigate performance impact
of partial_reg_stall vs partial_reg_dependency on Haswell for GCC 9.  In
the meantime, this patch restores both partial_reg_dependency and mox for
Haswell in GCC 8.

On Haswell, improvements for EEMBC benchmarks with

-mtune-ctrl=movx,partial_reg_dependency -Ofast -march=haswell

vs

-Ofast -mtune=haswell

are

automotive
=========
  aifftr01 (default) - goodperf: Runtime improvement of   2.6% (time).
  aiifft01 (default) - goodperf: Runtime improvement of   2.2% (time).

networking
=========
  ip_pktcheckb1m (default) - goodperf: Runtime improvement of   3.8% (time).
  ip_pktcheckb2m (default) - goodperf: Runtime improvement of   5.2% (time).
  ip_pktcheckb4m (default) - goodperf: Runtime improvement of   4.4% (time).
  ip_pktcheckb512k (default) - goodperf: Runtime improvement of   4.2% (time).

telecom
=========
  fft00data_1 (default) - goodperf: Runtime improvement of   8.4% (time).
  fft00data_2 (default) - goodperf: Runtime improvement of   8.6% (time).
  fft00data_3 (default) - goodperf: Runtime improvement of   9.0% (time).

	PR target/85829
	* config/i386/x86-tune.def: Re-enable partial_reg_dependency
	and movx for Haswell.

From-SVN: r261028

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c9cf570599c20c998db3db5fb729ce5171c67497..36c7a86d3902471d30b5f302f4e06c702a0aca24 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2018-05-31  H.J. Lu  <hongjiu.lu@intel.com>
+
+       PR target/85829
+       * config/i386/x86-tune.def: Re-enable partial_reg_dependency
+       and movx for Haswell.
+
 2018-05-31  Chung-Lin Tang  <cltang@codesourcery.com>
            Cesar Philippidis  <cesar@codesourcery.com>
 

diff --git a/gcc/config/i386/x86-tune.def b/gcc/config/i386/x86-tune.def
index 77d99340ebe5c75a4bf993de59330689c67125dc..f95c0701d5dbeea32d566347bd1a4077139214a9 100644 (file)
--- a/gcc/config/i386/x86-tune.def
+++ b/gcc/config/i386/x86-tune.def
@@ -49,7 +49,7 @@ DEF_TUNE (X86_TUNE_SCHEDULE, "schedule",
    over partial stores.  For example preffer MOVZBL or MOVQ to load 8bit
    value over movb.  */
 DEF_TUNE (X86_TUNE_PARTIAL_REG_DEPENDENCY, "partial_reg_dependency",
-          m_P4_NOCONA | m_CORE2 | m_NEHALEM  | m_SANDYBRIDGE
+          m_P4_NOCONA | m_CORE2 | m_NEHALEM  | m_SANDYBRIDGE | m_HASWELL
          | m_BONNELL | m_SILVERMONT | m_GOLDMONT | m_GOLDMONT_PLUS | m_INTEL
          | m_KNL | m_KNM | m_AMD_MULTIPLE | m_SKYLAKE_AVX512 | m_GENERIC)
 
@@ -87,7 +87,7 @@ DEF_TUNE (X86_TUNE_MOVX, "movx",
           m_PPRO | m_P4_NOCONA | m_CORE2 | m_NEHALEM  | m_SANDYBRIDGE
          | m_BONNELL | m_SILVERMONT | m_GOLDMONT | m_KNL | m_KNM | m_INTEL
          | m_GOLDMONT_PLUS | m_GEODE | m_AMD_MULTIPLE | m_SKYLAKE_AVX512
-         | m_GENERIC)
+         | m_HASWELL | m_GENERIC)
 
 /* X86_TUNE_MEMORY_MISMATCH_STALL: Avoid partial stores that are followed by
    full sized loads.  */