[PATCH v1 1/2] Match: Support unsigned scalar SAT_MUL form 13

[pan2 . li]

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

This patch would like to try to match the the unsigned
SAT_MUL form 13, aka below

  #define DEF_SAT_U_MUL_FMT_13(NT, WT)             \
  NT __attribute__((noinline))                     \
  sat_u_mul_##NT##_from_##WT##_fmt_13 (NT a, NT b) \
  {                                                \
    WT x = (WT)a * (WT)b;                          \
    if ((x >> sizeof(a) * 8) != 0)                 \
      return (NT)-1;                               \
    else                                           \
      return (NT)x;                                \
  }

while WT is uint128_t, uint64_t, uint32_t and uint16_t, and
NT is uint64_t, uint32_t, uint16_t or uint8_t.

gcc/ChangeLog:

        * match-sat-alu.pd: Add pattern for unsigned scalar
        SAT_MUL form 13.

Signed-off-by: Pan Li <pan2...@intel.com>
---
 gcc/match-sat-alu.pd | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/gcc/match-sat-alu.pd b/gcc/match-sat-alu.pd
index 6145a0c9948..1f27817a6c0 100644
--- a/gcc/match-sat-alu.pd
+++ b/gcc/match-sat-alu.pd
@@ -524,6 +524,31 @@ along with GCC; see the file COPYING3.  If not see
       bool c2_is_type_precision_p = c2 == prec;
      }
      (if (widen_prec > prec && c2_is_type_precision_p && c4_is_max_p)))))
+  (match (unsigned_integer_sat_mul @0 @1)
+   /* SAT_U_MUL (X, Y) = {
+       WT x = (WT)a * (WT)b;
+       if ((x >> sizeof(a) * 8) != 0)
+         return (T)-1;
+       else
+         return (T)x;
+      }
+      while WT is uint128_t, T is uint8_t, uint16_t, uint32_t or uint64_t.  */
+   (convert (cond^ (ne (rshift (mult:c@3 (convert @0) (convert @1))
+                              INTEGER_CST@2)
+                      integer_zerop)
+                  INTEGER_CST@4 @3))
+   (if (types_match (type, @0, @1))
+    (with
+     {
+      unsigned prec = TYPE_PRECISION (type);
+      unsigned widen_prec = TYPE_PRECISION (TREE_TYPE (@3));
+      wide_int c4 = wi::to_wide (@4);
+      wide_int max = wi::mask (prec, false, widen_prec);
+      bool c4_is_max_p = wi::eq_p (c4, max);
+      unsigned c2 = tree_to_uhwi (@2);
+      bool c2_is_type_precision_p = c2 == prec;
+     }
+     (if (widen_prec > prec && c2_is_type_precision_p && c4_is_max_p)))))
   (match (unsigned_integer_sat_mul @0 @1)
    /* SAT_U_MUL (X, Y) = {
        WT x = (WT)a * (WT)b;
-- 
2.43.0