[PATCH v1 1/2] Match: Introduce mul based pattern for unsigned SAT_MUL

[pan2 . li]

From: Pan Li <pan2...@intel.com>

Like widen_mul based pattern, we would like introduce the mul based
pattern as well.  The pattern is quite simple compares to the
widen_mul, thus add new instead of the for loop in match.pd.

gcc/ChangeLog:

        * match.pd: Add mul based unsigned SAT_MUL.

Signed-off-by: Pan Li <pan2...@intel.com>
---
 gcc/match.pd | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/gcc/match.pd b/gcc/match.pd
index 4903552c82a..f8d74fd52ad 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3611,6 +3611,18 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
       bool widen_mult_p = cvt5_prec == cvt6_prec && widen_prec == cvt6_prec * 
2;
      }
      (if (widen_prec > prec && c2_is_max_p && widen_mult_p)))))
+  (match (unsigned_integer_sat_mul @0 @1)
+   (convert@4 (min (mult:c@3 (convert @0) (convert @1)) INTEGER_CST@2))
+   (if (types_match (type, @0, @1) && types_match (type, @4))
+    (with
+     {
+      unsigned prec = TYPE_PRECISION (type);
+      unsigned widen_prec = TYPE_PRECISION (TREE_TYPE (@3));
+      wide_int c2 = wi::to_wide (@2);
+      wide_int max = wi::mask (prec, false, widen_prec);
+      bool c2_is_max_p = wi::eq_p (c2, max);
+     }
+     (if (widen_prec > prec && c2_is_max_p)))))
 )
 
 /* The boundary condition for case 10: IMM = 1:
-- 
2.43.0