r259399, which added PROCESSOR_SKYLAKE, disabled many x86 optimizations
which are enabled by PROCESSOR_HASWELL. As the result, -mtune=skylake
generates slower codes on Skylake than before. The same also applies
to Cannonlake and Icelak tuning.
This patch changes -mtune={skylake|cannonlake|icelake} to tune like
-mtune=haswell for until their tuning is properly adjusted. It also
enables -mprefer-vector-width=256 for -mtune=haswell, which has no
impact on codegen when AVX512 isn't enabled.
Performance impacts on SPEC CPU 2017 rate with 1 copy using
-march=native -mfpmath=sse -O2 -m64
are
1. On Broadwell server:
500.perlbench_r -0.56%
502.gcc_r -0.18%
505.mcf_r 0.24%
520.omnetpp_r 0.00%
523.xalancbmk_r -0.32%
525.x264_r -0.17%
531.deepsjeng_r 0.00%
541.leela_r 0.00%
548.exchange2_r 0.12%
557.xz_r 0.00%
geomean 0.00%
503.bwaves_r 0.00%
507.cactuBSSN_r 0.21%
508.namd_r 0.00%
510.parest_r 0.19%
511.povray_r -0.48%
519.lbm_r 0.00%
521.wrf_r 0.28%
526.blender_r 0.19%
527.cam4_r 0.39%
538.imagick_r 0.00%
544.nab_r -0.36%
549.fotonik3d_r 0.51%
554.roms_r 0.00%
geomean 0.17%
On Skylake client:
500.perlbench_r 0.96%
502.gcc_r 0.13%
505.mcf_r -1.03%
520.omnetpp_r -1.11%
523.xalancbmk_r 1.02%
525.x264_r 0.50%
531.deepsjeng_r 2.97%
541.leela_r 0.50%
548.exchange2_r -0.95%
557.xz_r 2.41%
geomean 0.56%
503.bwaves_r 0.49%
507.cactuBSSN_r 3.17%
508.namd_r 4.05%
510.parest_r 0.15%
511.povray_r 0.80%
519.lbm_r 3.15%
521.wrf_r 10.56%
526.blender_r 2.97%
527.cam4_r 2.36%
538.imagick_r 46.40%
544.nab_r 2.04%
549.fotonik3d_r 0.00%
554.roms_r 1.27%
geomean 5.49%
On Skylake server:
500.perlbench_r 0.71%
502.gcc_r -0.51%
505.mcf_r -1.06%
520.omnetpp_r -0.33%
523.xalancbmk_r -0.22%
525.x264_r 1.72%
531.deepsjeng_r -0.26%
541.leela_r 0.57%
548.exchange2_r -0.75%
557.xz_r -1.28%
geomean -0.21%
503.bwaves_r 0.00%
507.cactuBSSN_r 2.66%
508.namd_r 3.67%
510.parest_r 1.25%
511.povray_r 2.26%
519.lbm_r 1.69%
521.wrf_r 11.03%
526.blender_r 3.39%
527.cam4_r 1.69%
538.imagick_r 64.59%
544.nab_r -0.54%
549.fotonik3d_r 2.68%
554.roms_r 0.00%
geomean 6.19%
This patch improves -march=native performance on Skylake up to 60% and
leaves -march=native performance unchanged on Haswell.
OK for trunk?
Thanks.
H.J.
---
gcc/
2018-07-12 H.J. Lu <hongjiu...@intel.com>
Sunil K Pandey <sunil.k.pan...@intel.com>
PR target/84413
* config/i386/i386.c (m_HASWELL): Add PROCESSOR_SKYLAKE,
PROCESSOR_SKYLAKE_AVX512, PROCESSOR_CANNONLAKE,
PROCESSOR_ICELAKE_CLIENT and PROCESSOR_ICELAKE_SERVER.
(m_SKYLAKE): Set to 0.
(m_SKYLAKE_AVX512): Likewise.
(m_CANNONLAKE): Likewise.
(m_ICELAKE_CLIENT): Likewise.
(m_ICELAKE_SERVER): Likewise.
* config/i386/x86-tune.def (avx256_optimal): Also enabled for
m_HASWELL.
gcc/testsuite/
2018-07-12 H.J. Lu <hongjiu...@intel.com>
Sunil K Pandey <sunil.k.pan...@intel.com>
PR target/84413
* gcc.target/i386/pr84413-1.c: New test.
* gcc.target/i386/pr84413-2.c: Likewise.
* gcc.target/i386/pr84413-3.c: Likewise.
* gcc.target/i386/pr84413-4.c: Likewise.
---
gcc/config/i386/i386.c | 17 +++++++++++------
gcc/config/i386/x86-tune.def | 9 ++++++---
gcc/testsuite/gcc.target/i386/pr84413-1.c | 17 +++++++++++++++++
gcc/testsuite/gcc.target/i386/pr84413-2.c | 17 +++++++++++++++++
gcc/testsuite/gcc.target/i386/pr84413-3.c | 17 +++++++++++++++++
gcc/testsuite/gcc.target/i386/pr84413-4.c | 17 +++++++++++++++++
6 files changed, 85 insertions(+), 9 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr84413-1.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr84413-2.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr84413-3.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr84413-4.c
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 9e46b7b136f..762ab89fc9e 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -137,17 +137,22 @@ const struct processor_costs *ix86_cost = NULL;
#define m_CORE2 (HOST_WIDE_INT_1U<<PROCESSOR_CORE2)
#define m_NEHALEM (HOST_WIDE_INT_1U<<PROCESSOR_NEHALEM)
#define m_SANDYBRIDGE (HOST_WIDE_INT_1U<<PROCESSOR_SANDYBRIDGE)
-#define m_HASWELL (HOST_WIDE_INT_1U<<PROCESSOR_HASWELL)
+#define m_HASWELL ((HOST_WIDE_INT_1U<<PROCESSOR_HASWELL) \
+ | (HOST_WIDE_INT_1U<<PROCESSOR_SKYLAKE) \
+ | (HOST_WIDE_INT_1U<<PROCESSOR_SKYLAKE_AVX512) \
+ | (HOST_WIDE_INT_1U<<PROCESSOR_CANNONLAKE) \
+ | (HOST_WIDE_INT_1U<<PROCESSOR_ICELAKE_CLIENT) \
+ | (HOST_WIDE_INT_1U<<PROCESSOR_ICELAKE_SERVER))
#define m_CORE_ALL (m_CORE2 | m_NEHALEM | m_SANDYBRIDGE | m_HASWELL)
#define m_BONNELL (HOST_WIDE_INT_1U<<PROCESSOR_BONNELL)
#define m_SILVERMONT (HOST_WIDE_INT_1U<<PROCESSOR_SILVERMONT)
#define m_KNL (HOST_WIDE_INT_1U<<PROCESSOR_KNL)
#define m_KNM (HOST_WIDE_INT_1U<<PROCESSOR_KNM)
-#define m_SKYLAKE (HOST_WIDE_INT_1U<<PROCESSOR_SKYLAKE)
-#define m_SKYLAKE_AVX512 (HOST_WIDE_INT_1U<<PROCESSOR_SKYLAKE_AVX512)
-#define m_CANNONLAKE (HOST_WIDE_INT_1U<<PROCESSOR_CANNONLAKE)
-#define m_ICELAKE_CLIENT (HOST_WIDE_INT_1U<<PROCESSOR_ICELAKE_CLIENT)
-#define m_ICELAKE_SERVER (HOST_WIDE_INT_1U<<PROCESSOR_ICELAKE_SERVER)
+#define m_SKYLAKE 0
+#define m_SKYLAKE_AVX512 0
+#define m_CANNONLAKE 0
+#define m_ICELAKE_CLIENT 0
+#define m_ICELAKE_SERVER 0
#define m_GOLDMONT (HOST_WIDE_INT_1U<<PROCESSOR_GOLDMONT)
#define m_GOLDMONT_PLUS (HOST_WIDE_INT_1U<<PROCESSOR_GOLDMONT_PLUS)
#define m_TREMONT (HOST_WIDE_INT_1U<<PROCESSOR_TREMONT)
diff --git a/gcc/config/i386/x86-tune.def b/gcc/config/i386/x86-tune.def
index 8a8d5ab2440..c8abaedad8c 100644
--- a/gcc/config/i386/x86-tune.def
+++ b/gcc/config/i386/x86-tune.def
@@ -444,9 +444,12 @@ DEF_TUNE (X86_TUNE_AVX256_UNALIGNED_STORE_OPTIMAL,
"256_unaligned_store_optimal"
DEF_TUNE (X86_TUNE_AVX128_OPTIMAL, "avx128_optimal", m_BDVER | m_BTVER2
| m_ZNVER1)
-/* X86_TUNE_AVX256_OPTIMAL: Use 256-bit AVX instructions instead of 512-bit AVX
- instructions in the auto-vectorizer. */
-DEF_TUNE (X86_TUNE_AVX256_OPTIMAL, "avx256_optimal", m_SKYLAKE_AVX512)
+/* X86_TUNE_AVX256_OPTIMAL: Use 256-bit AVX instructions instead of 512-bit
+ AVX instructions in the auto-vectorizer. NB: This is also enabled for
+ -mtune=haswell so that we can tune Skylake, Cannonlake and Icelake as
+ Haswell. */
+DEF_TUNE (X86_TUNE_AVX256_OPTIMAL, "avx256_optimal", m_SKYLAKE_AVX512
+ | m_HASWELL)
/*****************************************************************************/
/* Historical relics: tuning flags that helps a specific old CPU designs */
diff --git a/gcc/testsuite/gcc.target/i386/pr84413-1.c
b/gcc/testsuite/gcc.target/i386/pr84413-1.c
new file mode 100644
index 00000000000..1c94d7715cf
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr84413-1.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -march=skylake-avx512" } */
+/* { dg-final { scan-assembler-not "%zmm\[0-9\]+" } } */
+/* { dg-final { scan-assembler "vmulpd\[ \\t\]+\[^\n\]*%ymm\[0-9\]+" } } */
+
+#define N 1024
+
+double a[N], b[N], c[N];
+
+void
+avx512f_test (void)
+{
+ int i;
+
+ for (i = 0; i < N; i++)
+ c[i] = a[i] * b[i];
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr84413-2.c
b/gcc/testsuite/gcc.target/i386/pr84413-2.c
new file mode 100644
index 00000000000..adf9b527cd6
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr84413-2.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -march=cannonlake" } */
+/* { dg-final { scan-assembler-not "%zmm\[0-9\]+" } } */
+/* { dg-final { scan-assembler "vmulpd\[ \\t\]+\[^\n\]*%ymm\[0-9\]+" } } */
+
+#define N 1024
+
+double a[N], b[N], c[N];
+
+void
+avx512f_test (void)
+{
+ int i;
+
+ for (i = 0; i < N; i++)
+ c[i] = a[i] * b[i];
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr84413-3.c
b/gcc/testsuite/gcc.target/i386/pr84413-3.c
new file mode 100644
index 00000000000..76bf25fc56b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr84413-3.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -march=icelake-server" } */
+/* { dg-final { scan-assembler-not "%zmm\[0-9\]+" } } */
+/* { dg-final { scan-assembler "vmulpd\[ \\t\]+\[^\n\]*%ymm\[0-9\]+" } } */
+
+#define N 1024
+
+double a[N], b[N], c[N];
+
+void
+avx512f_test (void)
+{
+ int i;
+
+ for (i = 0; i < N; i++)
+ c[i] = a[i] * b[i];
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr84413-4.c
b/gcc/testsuite/gcc.target/i386/pr84413-4.c
new file mode 100644
index 00000000000..031ef0c8916
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr84413-4.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -march=haswell -mavx512f" } */
+/* { dg-final { scan-assembler-not "%zmm\[0-9\]+" } } */
+/* { dg-final { scan-assembler "vmulpd\[ \\t\]+\[^\n\]*%ymm\[0-9\]+" } } */
+
+#define N 1024
+
+double a[N], b[N], c[N];
+
+void
+avx512f_test (void)
+{
+ int i;
+
+ for (i = 0; i < N; i++)
+ c[i] = a[i] * b[i];
+}
--
2.17.1
