[gcc r14-7124] Optimize A < B ? A : B to MIN_EXPR.

[hongtao Liu]

https://gcc.gnu.org/g:6686e16fda419067b91614835dd743ebb82717ea

commit r14-7124-g6686e16fda419067b91614835dd743ebb82717ea
Author: liuhongt <hongtao.liu@intel.com>
Date:   Tue Dec 19 10:39:06 2023 +0800

    Optimize A < B ? A : B to MIN_EXPR.
    
    Similar for A < B ? B : A to MAX_EXPR.
    There're codes in the frontend to optimize such pattern but failed to
    handle testcase in the PR since it's exposed at gimple level when
    folding backend builtins.
    
    pr95906 now can be optimized to MAX_EXPR as it's commented in the
    testcase.
    
    // FIXME: this should further optimize to a MAX_EXPR
     typedef signed char v16i8 __attribute__((vector_size(16)));
     v16i8 f(v16i8 a, v16i8 b)
    
    gcc/ChangeLog:
    
            PR target/104401
            * match.pd (VEC_COND_EXPR: A < B ? A : B -> MIN_EXPR): New patten match.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.target/i386/pr104401.c: New test.
            * gcc.dg/tree-ssa/pr95906.c: Adjust testcase.

Diff:
---
 gcc/match.pd                             | 21 +++++++++++++++++++++
 gcc/testsuite/gcc.dg/tree-ssa/pr95906.c  |  3 +--
 gcc/testsuite/gcc.target/i386/pr104401.c | 27 +++++++++++++++++++++++++++
 3 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/gcc/match.pd b/gcc/match.pd
index d75babd86c2..876a9d1c06e 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -5684,6 +5684,27 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
       (if (VECTOR_TYPE_P (type))
        (view_convert @c0)
        (convert @c0))))))))
+
+/* This is for VEC_COND_EXPR
+   Optimize A < B ? A : B to MIN (A, B)
+	    A > B ? A : B to MAX (A, B).  */
+(for cmp (lt le ungt unge gt ge unlt unle)
+     minmax (min min min min max max max max)
+     MINMAX (MIN_EXPR MIN_EXPR MIN_EXPR MIN_EXPR MAX_EXPR MAX_EXPR MAX_EXPR MAX_EXPR)
+ (simplify
+  (vec_cond (cmp @0 @1) @0 @1)
+   (if (VECTOR_INTEGER_TYPE_P (type)
+       && target_supports_op_p (type, MINMAX, optab_vector))
+    (minmax @0 @1))))
+
+(for cmp (lt le ungt unge gt ge unlt unle)
+     minmax (max max max max min min min min)
+     MINMAX (MAX_EXPR MAX_EXPR MAX_EXPR MAX_EXPR MIN_EXPR MIN_EXPR MIN_EXPR MIN_EXPR)
+ (simplify
+  (vec_cond (cmp @0 @1) @1 @0)
+   (if (VECTOR_INTEGER_TYPE_P (type)
+       && target_supports_op_p (type, MINMAX, optab_vector))
+    (minmax @0 @1))))
 #endif
 
 (for cnd (cond vec_cond)
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr95906.c b/gcc/testsuite/gcc.dg/tree-ssa/pr95906.c
index 3d820a58e93..d15670f3e9e 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/pr95906.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr95906.c
@@ -1,7 +1,6 @@
 /* { dg-do compile } */
 /* { dg-options "-O2 -fdump-tree-forwprop3-raw -w -Wno-psabi" } */
 
-// FIXME: this should further optimize to a MAX_EXPR
 typedef signed char v16i8 __attribute__((vector_size(16)));
 v16i8 f(v16i8 a, v16i8 b)
 {
@@ -10,4 +9,4 @@ v16i8 f(v16i8 a, v16i8 b)
 }
 
 /* { dg-final { scan-tree-dump-not "bit_(and|ior)_expr" "forwprop3" } } */
-/* { dg-final { scan-tree-dump-times "vec_cond_expr" 1 "forwprop3" } } */
+/* { dg-final { scan-tree-dump-times "max_expr" 1 "forwprop3" } } */
diff --git a/gcc/testsuite/gcc.target/i386/pr104401.c b/gcc/testsuite/gcc.target/i386/pr104401.c
new file mode 100644
index 00000000000..8ce7ff88d9e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr104401.c
@@ -0,0 +1,27 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -msse4.1" } */
+/* { dg-final { scan-assembler-times "pminsd" 2 } } */
+/* { dg-final { scan-assembler-times "pmaxsd" 2 } } */
+
+#include <smmintrin.h>
+
+__m128i min32(__m128i value, __m128i input)
+{
+  return _mm_blendv_epi8(input, value, _mm_cmplt_epi32(value, input));
+}
+
+__m128i max32(__m128i value, __m128i input)
+{
+  return _mm_blendv_epi8(input, value, _mm_cmpgt_epi32(value, input));
+}
+
+__m128i min32_1(__m128i value, __m128i input)
+{
+  return _mm_blendv_epi8(input, value, _mm_cmpgt_epi32(input, value));
+}
+
+__m128i max32_1(__m128i value, __m128i input)
+{
+  return _mm_blendv_epi8(input, value, _mm_cmplt_epi32(input, value));
+}
+