From: Pan Li <pan2.li@intel.com>
Date: Fri, 1 Aug 2025 02:37:58 +0000 (+0800)
Subject: Match: Add form 2 for unsigned SAT_MUL
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=deb0a4c80414697d07e808b1d2500229eb281600;p=thirdparty%2Fgcc.git

Match: Add form 2 for unsigned SAT_MUL

This patch would like to try to match the the unsigned
SAT_MUL form 2, aka below:

  #define DEF_SAT_U_MUL_FMT_2(T)               \
  T __attribute__((noinline))                  \
  sat_u_mul_##T##_fmt_2 (T a, T b)             \
  {                                            \
    T result;                                  \
    if (__builtin_mul_overflow(a, b, &result)) \
      return -1;                               \
    else                                       \
      return result;                           \
  }

While T is uint8_t, uint16_t, uint32_t and uint64_t.

gcc/ChangeLog:

	* match.pd: Add form 2 for unsigned SAT_MUL.

Signed-off-by: Pan Li <pan2.li@intel.com>
---

diff --git a/gcc/match.pd b/gcc/match.pd
index 06a4a91579f..66e8a787449 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3623,6 +3623,18 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
       bool c2_is_max_p = wi::eq_p (c2, max);
      }
      (if (widen_prec > prec && c2_is_max_p)))))
+  (match (unsigned_integer_sat_mul @0 @1)
+   /* SAT_U_MUL (X, Y) = {
+	T result;
+	if (__builtin_mul_overflow (X, Y, &result))
+	  return -1;
+	else
+	  return -(T)overflow_p | result;
+      }
+      while T can be uint8_t, uint16_t, uint32_t and uint64_t.  */
+   (cond^ (ne (imagpart (IFN_MUL_OVERFLOW:c@2 @0 @1)) integer_zerop)
+	   integer_minus_onep (realpart @2))
+   (if (types_match (type, @0, @1))))
 )
 
 /* The boundary condition for case 10: IMM = 1: