Vect: Support form 1 of vector signed integer .SAT_ADD

This patch would like to support the vector signed ssadd pattern
for the RISC-V backend.  Aka

Form 1:
  #define DEF_VEC_SAT_S_ADD_FMT_1(T, UT, MIN, MAX)           \
  void __attribute__((noinline))                             \
  vec_sat_s_add_##T##_fmt_1 (T *out, T *x, T *y, unsigned n) \
  {                                                          \
    for (unsigned i = 0; i < n; i++)                         \
      {                                                      \
        T sum = (UT)x[i] + (UT)y[i];                         \
        out[i] = (x[i] ^ y[i]) < 0                           \
          ? sum                                              \
          : (sum ^ x[i]) >= 0                                \
            ? sum                                            \
            : x[i] < 0 ? MIN : MAX;                          \
      }                                                      \
  }

DEF_VEC_SAT_S_ADD_FMT_1(int64_t, uint64_t, INT64_MIN, INT64_MAX)

If the backend implemented the vector mode of ssadd, we will see IR diff
similar as below:

Before this patch:
 108   │   _114 = .SELECT_VL (ivtmp_112, POLY_INT_CST [2, 2]);
 109   │   ivtmp_77 = _114 * 8;
 110   │   vect__4.9_80 = .MASK_LEN_LOAD (vectp_x.7_78, 64B, { -1, ...  }, _114, 0);
 111   │   vect__5.10_81 = VIEW_CONVERT_EXPR<vector([2,2]) long unsigned int>(vect__4.9_80);
 112   │   vect__7.13_85 = .MASK_LEN_LOAD (vectp_y.11_83, 64B, { -1, ...  }, _114, 0);
 113   │   vect__8.14_86 = VIEW_CONVERT_EXPR<vector([2,2]) long unsigned int>(vect__7.13_85);
 114   │   vect__9.15_87 = vect__5.10_81 + vect__8.14_86;
 115   │   vect_sum_20.16_88 = VIEW_CONVERT_EXPR<vector([2,2]) long int>(vect__9.15_87);
 116   │   vect__10.17_89 = vect__4.9_80 ^ vect__7.13_85;
 117   │   vect__11.18_90 = vect__4.9_80 ^ vect_sum_20.16_88;
 118   │   mask__46.19_92 = vect__10.17_89 >= { 0, ... };
 119   │   _36 = vect__4.9_80 >> 63;
 120   │   mask__44.26_104 = vect__11.18_90 < { 0, ... };
 121   │   mask__43.27_105 = mask__46.19_92 & mask__44.26_104;
 122   │   _115 = .COND_XOR (mask__43.27_105, _36, { 9223372036854775807, ... }, vect_sum_20.16_88);
 123   │   .MASK_LEN_STORE (vectp_out.29_108, 64B, { -1, ... }, _114, 0, _115);
 124   │   vectp_x.7_79 = vectp_x.7_78 + ivtmp_77;
 125   │   vectp_y.11_84 = vectp_y.11_83 + ivtmp_77;
 126   │   vectp_out.29_109 = vectp_out.29_108 + ivtmp_77;
 127   │   ivtmp_113 = ivtmp_112 - _114;

After this patch:
  94   │   # vectp_x.7_82 = PHI <vectp_x.7_83(6), x_18(D)(5)>
  95   │   # vectp_y.10_86 = PHI <vectp_y.10_87(6), y_19(D)(5)>
  96   │   # vectp_out.14_91 = PHI <vectp_out.14_92(6), out_21(D)(5)>
  97   │   # ivtmp_95 = PHI <ivtmp_96(6), _94(5)>
  98   │   _97 = .SELECT_VL (ivtmp_95, POLY_INT_CST [2, 2]);
  99   │   ivtmp_81 = _97 * 8;
 100   │   vect__4.9_84 = .MASK_LEN_LOAD (vectp_x.7_82, 64B, { -1, ...  }, _97, 0);
 101   │   vect__7.12_88 = .MASK_LEN_LOAD (vectp_y.10_86, 64B, { -1, ...  }, _97, 0);
 102   │   vect_patt_40.13_89 = .SAT_ADD (vect__4.9_84, vect__7.12_88);
 103   │   .MASK_LEN_STORE (vectp_out.14_91, 64B, { -1, ... }, _97, 0, vect_patt_40.13_89);
 104   │   vectp_x.7_83 = vectp_x.7_82 + ivtmp_81;
 105   │   vectp_y.10_87 = vectp_y.10_86 + ivtmp_81;
 106   │   vectp_out.14_92 = vectp_out.14_91 + ivtmp_81;
 107   │   ivtmp_96 = ivtmp_95 - _97;

The below test suites are passed for this patch:
1. The rv64gcv fully regression tests.
2. The x86 bootstrap tests.
3. The x86 fully regression tests.

gcc/ChangeLog:

	* match.pd: Add case 2 for the signed .SAT_ADD consumed by
	vect pattern.
	* tree-vect-patterns.cc (gimple_signed_integer_sat_add): Add new
	matching func decl for signed .SAT_ADD.
	(vect_recog_sat_add_pattern): Add signed .SAT_ADD pattern match.

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

1 files changed, 4 insertions, 1 deletions

diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc
index 3a0d4cb..a2bf90a 100644
--- a/gcc/tree-vect-patterns.cc
+++ b/gcc/tree-vect-patterns.cc
@@ -4497,6 +4497,8 @@ extern bool gimple_unsigned_integer_sat_add (tree, tree*, tree (*)(tree));
 extern bool gimple_unsigned_integer_sat_sub (tree, tree*, tree (*)(tree));
 extern bool gimple_unsigned_integer_sat_trunc (tree, tree*, tree (*)(tree));
 
+extern bool gimple_signed_integer_sat_add (tree, tree*, tree (*)(tree));
+
 static gimple *
 vect_recog_build_binary_gimple_stmt (vec_info *vinfo, stmt_vec_info stmt_info,
 				     internal_fn fn, tree *type_out,
@@ -4557,7 +4559,8 @@ vect_recog_sat_add_pattern (vec_info *vinfo, stmt_vec_info stmt_vinfo,
   tree ops[2];
   tree lhs = gimple_assign_lhs (last_stmt);
 
-  if (gimple_unsigned_integer_sat_add (lhs, ops, NULL))
+  if (gimple_unsigned_integer_sat_add (lhs, ops, NULL)
+      || gimple_signed_integer_sat_add (lhs, ops, NULL))
     {
       if (TREE_CODE (ops[1]) == INTEGER_CST)
 	ops[1] = fold_convert (TREE_TYPE (ops[0]), ops[1]);