[gcc r12-2981] Add x86 tune to enable v2df vector reduction by paddpd.

[gcc r12-2981] Add x86 tune to enable v2df vector reduction by paddpd.

[hongtao Liu]

https://gcc.gnu.org/g:97d51c1764554fcef05fe94ee6445f5d2252bcff

commit r12-2981-g97d51c1764554fcef05fe94ee6445f5d2252bcff
Author: liuhongt <hongtao.liu@intel.com>
Date:   Tue Aug 17 13:11:26 2021 +0800

    Add x86 tune to enable v2df vector reduction by paddpd.
    
    The tune is disabled by default.
    
    gcc/ChangeLog:
    
            PR target/97147
            * config/i386/i386.h (TARGET_V2DF_REDUCTION_PREFER_HADDPD):
            New macro.
            * config/i386/sse.md (*sse3_haddv2df3_low): Add
            TARGET_V2DF_REDUCTION_PREFER_HADDPD.
            (*sse3_hsubv2df3_low): Ditto.
            * config/i386/x86-tune.def
            (X86_TUNE_V2DF_REDUCTION_PREFER_HADDPD): New tune.
    
    gcc/testsuite/ChangeLog:
    
            PR target/97147
            * gcc.target/i386/pr54400.c: Adjust testcase.
            * gcc.target/i386/pr94147.c: New test.

Diff:
---
 gcc/config/i386/i386.h                  |  2 ++
 gcc/config/i386/sse.md                  |  4 ++--
 gcc/config/i386/x86-tune.def            |  5 +++++
 gcc/testsuite/gcc.target/i386/pr54400.c |  2 +-
 gcc/testsuite/gcc.target/i386/pr94147.c | 22 ++++++++++++++++++++++
 5 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index 21fe51bba40..b3e57a83846 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -418,6 +418,8 @@ extern unsigned char ix86_tune_features[X86_TUNE_LAST];
 	ix86_tune_features[X86_TUNE_EMIT_VZEROUPPER]
 #define TARGET_EXPAND_ABS \
 	ix86_tune_features[X86_TUNE_EXPAND_ABS]
+#define TARGET_V2DF_REDUCTION_PREFER_HADDPD \
+	ix86_tune_features[X86_TUNE_V2DF_REDUCTION_PREFER_HADDPD]
 
 /* Feature tests against the various architecture variations.  */
 enum ix86_arch_indices {
diff --git a/gcc/config/i386/sse.md b/gcc/config/i386/sse.md
index 27e25cc7952..13889687793 100644
--- a/gcc/config/i386/sse.md
+++ b/gcc/config/i386/sse.md
@@ -2771,7 +2771,7 @@
 	  (vec_select:DF
 	    (match_dup 1)
 	    (parallel [(match_operand:SI 3 "const_0_to_1_operand")]))))]
-  "TARGET_SSE3
+  "TARGET_SSE3 && TARGET_V2DF_REDUCTION_PREFER_HADDPD
    && INTVAL (operands[2]) != INTVAL (operands[3])"
   "@
    haddpd\t{%0, %0|%0, %0}
@@ -2790,7 +2790,7 @@
 	  (vec_select:DF
 	    (match_dup 1)
 	    (parallel [(const_int 1)]))))]
-  "TARGET_SSE3"
+  "TARGET_SSE3 && TARGET_V2DF_REDUCTION_PREFER_HADDPD"
   "@
    hsubpd\t{%0, %0|%0, %0}
    vhsubpd\t{%1, %1, %0|%0, %1, %1}"
diff --git a/gcc/config/i386/x86-tune.def b/gcc/config/i386/x86-tune.def
index eb057a67750..8f55da89c92 100644
--- a/gcc/config/i386/x86-tune.def
+++ b/gcc/config/i386/x86-tune.def
@@ -452,6 +452,11 @@ DEF_TUNE (X86_TUNE_AVOID_128FMA_CHAINS, "avoid_fma_chains", m_ZNVER)
    smaller FMA chain.  */
 DEF_TUNE (X86_TUNE_AVOID_256FMA_CHAINS, "avoid_fma256_chains", m_ZNVER2 | m_ZNVER3)
 
+/* X86_TUNE_V2DF_REDUCTION_PREFER_PHADDPD: Prefer haddpd
+   for v2df vector reduction.  */
+DEF_TUNE (X86_TUNE_V2DF_REDUCTION_PREFER_HADDPD,
+	  "v2df_reduction_prefer_haddpd", m_NONE)
+
 /*****************************************************************************/
 /* AVX instruction selection tuning (some of SSE flags affects AVX, too)     */
 /*****************************************************************************/
diff --git a/gcc/testsuite/gcc.target/i386/pr54400.c b/gcc/testsuite/gcc.target/i386/pr54400.c
index 5ed5ba06644..3a450376b9e 100644
--- a/gcc/testsuite/gcc.target/i386/pr54400.c
+++ b/gcc/testsuite/gcc.target/i386/pr54400.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -msse3 -mfpmath=sse" } */
+/* { dg-options "-O2 -msse3 -mfpmath=sse -mtune-ctrl=v2df_reduction_prefer_haddpd" } */
 
 #include <x86intrin.h>
 
diff --git a/gcc/testsuite/gcc.target/i386/pr94147.c b/gcc/testsuite/gcc.target/i386/pr94147.c
new file mode 100644
index 00000000000..8ff5c34834f
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr94147.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -msse3 -mfpmath=sse" } */
+
+#include <x86intrin.h>
+
+double f (__m128d p)
+{
+  return p[0] - p[1];
+}
+
+double g1 (__m128d p)
+{
+  return p[0] + p[1];
+}
+
+double g2 (__m128d p)
+{
+  return p[1] + p[0];
+}
+
+/* { dg-final { scan-assembler-not "hsubpd" } } */
+/* { dg-final { scan-assembler-not "haddpd" } } */