https://gcc.gnu.org/g:09ca98e854dca41ae0987b878a1eaab59b31383d

commit r16-5609-g09ca98e854dca41ae0987b878a1eaab59b31383d
Author: Pan Li <[email protected]>
Date:   Tue Nov 25 15:18:38 2025 +0800

    Match: Add unsigned SAT_MUL for form 7
    
    This patch would like to try to match the the unsigned
    SAT_MUL form 7, aka below:
    
      #define DEF_SAT_U_MUL_FMT_7(NT, WT)             \
      NT __attribute__((noinline))                    \
      sat_u_mul_##NT##_from_##WT##_fmt_7 (NT a, NT b) \
      {                                               \
        WT x = (WT)a * (WT)b;                         \
        NT max = -1;                                  \
        bool overflow_p = x > (WT)(max);              \
        return -(NT)(overflow_p) | (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.pd: Add pattern for SAT_MUL form 7 include
            mul and widen_mul.
    
    Signed-off-by: Pan Li <[email protected]>

Diff:
---
 gcc/match.pd | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/gcc/match.pd b/gcc/match.pd
index 36d8f2f72750..2877f81e7a51 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3793,6 +3793,25 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
       bool c2_is_type_precision_p = tree_to_uhwi (@2) == prec;
      }
      (if (c2_is_type_precision_p)))))
+  (match (unsigned_integer_sat_mul @0 @1)
+   /* SAT_U_MUL (X, Y) = {
+       WT x = (WT)a * (WT)b;
+       NT max = -1;
+       bool overflow_p = x > (WT)max;
+       return -(NT)(overflow_p) | (NT)x;
+      } while WT is uint128_t, uint64_t, uint32_t, uint16_t,
+       and T is uint64_t, uint32_t, uint16_t, uint8_t.  */
+   (bit_ior:c (negate (convert (gt @3 INTEGER_CST@2)))
+             (convert (usmul_widen_mult@3 @0 @1)))
+   (if (types_match (type, @0, @1))
+    (with
+     {
+      unsigned prec = TYPE_PRECISION (type);
+      unsigned widen_prec = TYPE_PRECISION (TREE_TYPE (@3));
+      wide_int max = wi::mask (prec, false, widen_prec);
+      bool c2_is_max_p = wi::eq_p (wi::to_wide (@2), max);
+     }
+     (if (c2_is_max_p)))))
 )
 
 /* The boundary condition for case 10: IMM = 1:

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