toolchain/gcc/patches/4.7-linaro/400-fix-incorrect-optimization.patch

   1 --- /dev/null
   2 +++ b/make/target/gcc/4.7.0/920-tree-ssa-tail-merge.patch
   3 @@ -0,0 +1,244 @@
   4 +This patch refers to:
   5 +
   6 +http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52734
   7 +http://gcc.gnu.org/bugzilla/attachment.cgi?id=27014&action=diff&context=patch&collapsed=&headers=1&format=raw
   8 +
   9 +--- gcc/tree-ssa-tail-merge.c
  10 ++++ gcc/tree-ssa-tail-merge.c
  11 +@@ -1033,7 +1033,7 @@ set_cluster (basic_block bb1, basic_bloc
  12 +    gimple_bb (s2) are members of SAME_SUCC.  */
  13 +
  14 + static bool
  15 +-gimple_equal_p (same_succ same_succ, gimple s1, gimple s2)
  16 ++gimple_equal_p (same_succ same_succ, gimple s1, gimple s2, bool *gvn_used)
  17 + {
  18 +   unsigned int i;
  19 +   tree lhs1, lhs2;
  20 +@@ -1069,7 +1069,10 @@ gimple_equal_p (same_succ same_succ, gim
  21 +         if (operand_equal_p (t1, t2, 0))
  22 +           continue;
  23 +         if (gvn_uses_equal (t1, t2))
  24 +-          continue;
  25 ++          {
  26 ++            *gvn_used = true;
  27 ++            continue;
  28 ++          }
  29 +         equal = false;
  30 +         break;
  31 +       }
  32 +@@ -1083,12 +1086,16 @@ gimple_equal_p (same_succ same_succ, gim
  33 +       if (lhs1 == NULL_TREE || lhs2 == NULL_TREE)
  34 +       return false;
  35 +       if (TREE_CODE (lhs1) == SSA_NAME && TREE_CODE (lhs2) == SSA_NAME)
  36 +-      return vn_valueize (lhs1) == vn_valueize (lhs2);
  37 ++      {
  38 ++        *gvn_used = true;
  39 ++        return vn_valueize (lhs1) == vn_valueize (lhs2);
  40 ++      }
  41 +       return operand_equal_p (lhs1, lhs2, 0);
  42 +
  43 +     case GIMPLE_ASSIGN:
  44 +       lhs1 = gimple_get_lhs (s1);
  45 +       lhs2 = gimple_get_lhs (s2);
  46 ++      *gvn_used = true;
  47 +       return (TREE_CODE (lhs1) == SSA_NAME
  48 +             && TREE_CODE (lhs2) == SSA_NAME
  49 +             && vn_valueize (lhs1) == vn_valueize (lhs2));
  50 +@@ -1096,15 +1103,23 @@ gimple_equal_p (same_succ same_succ, gim
  51 +     case GIMPLE_COND:
  52 +       t1 = gimple_cond_lhs (s1);
  53 +       t2 = gimple_cond_lhs (s2);
  54 +-      if (!operand_equal_p (t1, t2, 0)
  55 +-        && !gvn_uses_equal (t1, t2))
  56 +-      return false;
  57 ++      if (!operand_equal_p (t1, t2, 0))
  58 ++      {
  59 ++        if (gvn_uses_equal (t1, t2))
  60 ++          *gvn_used = true;
  61 ++        else
  62 ++          return false;
  63 ++      }
  64 +
  65 +       t1 = gimple_cond_rhs (s1);
  66 +       t2 = gimple_cond_rhs (s2);
  67 +-      if (!operand_equal_p (t1, t2, 0)
  68 +-        && !gvn_uses_equal (t1, t2))
  69 +-      return false;
  70 ++      if (!operand_equal_p (t1, t2, 0))
  71 ++      {
  72 ++        if (gvn_uses_equal (t1, t2))
  73 ++          *gvn_used = true;
  74 ++        else
  75 ++          return false;
  76 ++      }
  77 +
  78 +       code1 = gimple_expr_code (s1);
  79 +       code2 = gimple_expr_code (s2);
  80 +@@ -1126,18 +1141,25 @@ gimple_equal_p (same_succ same_succ, gim
  81 + /* Let GSI skip backwards over local defs.  */
  82 +
  83 + static void
  84 +-gsi_advance_bw_nondebug_nonlocal (gimple_stmt_iterator *gsi)
  85 ++gsi_advance_bw_nondebug_nonlocal (gimple_stmt_iterator *gsi, tree *vuse)
  86 + {
  87 +   gimple stmt;
  88 ++  tree lvuse;
  89 +
  90 +   while (true)
  91 +     {
  92 +       if (gsi_end_p (*gsi))
  93 +       return;
  94 +       stmt = gsi_stmt (*gsi);
  95 ++
  96 ++      lvuse = gimple_vuse (stmt);
  97 ++      if (lvuse != NULL_TREE)
  98 ++      *vuse = lvuse;
  99 ++
 100 +       if (!(is_gimple_assign (stmt) && local_def (gimple_get_lhs (stmt))
 101 +           && !gimple_has_side_effects (stmt)))
 102 +       return;
 103 ++
 104 +       gsi_prev_nondebug (gsi);
 105 +     }
 106 + }
 107 +@@ -1146,28 +1168,34 @@ gsi_advance_bw_nondebug_nonlocal (gimple
 108 +    clusters them.  */
 109 +
 110 + static void
 111 +-find_duplicate (same_succ same_succ, basic_block bb1, basic_block bb2)
 112 ++find_duplicate (same_succ same_succ, basic_block bb1, basic_block bb2,
 113 ++              bool gvn_used)
 114 + {
 115 +   gimple_stmt_iterator gsi1 = gsi_last_nondebug_bb (bb1);
 116 +   gimple_stmt_iterator gsi2 = gsi_last_nondebug_bb (bb2);
 117 ++  tree vuse1 = NULL_TREE, vuse2 = NULL_TREE;
 118 +
 119 +-  gsi_advance_bw_nondebug_nonlocal (&gsi1);
 120 +-  gsi_advance_bw_nondebug_nonlocal (&gsi2);
 121 ++  gsi_advance_bw_nondebug_nonlocal (&gsi1, &vuse1);
 122 ++  gsi_advance_bw_nondebug_nonlocal (&gsi2, &vuse2);
 123 +
 124 +   while (!gsi_end_p (gsi1) && !gsi_end_p (gsi2))
 125 +     {
 126 +-      if (!gimple_equal_p (same_succ, gsi_stmt (gsi1), gsi_stmt (gsi2)))
 127 ++      if (!gimple_equal_p (same_succ, gsi_stmt (gsi1), gsi_stmt (gsi2),
 128 ++                         &gvn_used))
 129 +       return;
 130 +
 131 +       gsi_prev_nondebug (&gsi1);
 132 +       gsi_prev_nondebug (&gsi2);
 133 +-      gsi_advance_bw_nondebug_nonlocal (&gsi1);
 134 +-      gsi_advance_bw_nondebug_nonlocal (&gsi2);
 135 ++      gsi_advance_bw_nondebug_nonlocal (&gsi1, &vuse1);
 136 ++      gsi_advance_bw_nondebug_nonlocal (&gsi2, &vuse2);
 137 +     }
 138 +
 139 +   if (!(gsi_end_p (gsi1) && gsi_end_p (gsi2)))
 140 +     return;
 141 +
 142 ++  if (gvn_used && vuse1 != vuse2)
 143 ++    return;
 144 ++
 145 +   if (dump_file)
 146 +     fprintf (dump_file, "find_duplicates: <bb %d> duplicate of <bb %d>\n",
 147 +            bb1->index, bb2->index);
 148 +@@ -1179,7 +1207,7 @@ find_duplicate (same_succ same_succ, bas
 149 +    E2 are equal.  */
 150 +
 151 + static bool
 152 +-same_phi_alternatives_1 (basic_block dest, edge e1, edge e2)
 153 ++same_phi_alternatives_1 (basic_block dest, edge e1, edge e2, bool *gvn_used)
 154 + {
 155 +   int n1 = e1->dest_idx, n2 = e2->dest_idx;
 156 +   gimple_stmt_iterator gsi;
 157 +@@ -1197,7 +1225,10 @@ same_phi_alternatives_1 (basic_block des
 158 +       if (operand_equal_for_phi_arg_p (val1, val2))
 159 +         continue;
 160 +       if (gvn_uses_equal (val1, val2))
 161 +-      continue;
 162 ++      {
 163 ++        *gvn_used = true;
 164 ++        continue;
 165 ++      }
 166 +
 167 +       return false;
 168 +     }
 169 +@@ -1209,7 +1240,8 @@ same_phi_alternatives_1 (basic_block des
 170 +    phi alternatives for BB1 and BB2 are equal.  */
 171 +
 172 + static bool
 173 +-same_phi_alternatives (same_succ same_succ, basic_block bb1, basic_block bb2)
 174 ++same_phi_alternatives (same_succ same_succ, basic_block bb1, basic_block bb2,
 175 ++                     bool *gvn_used)
 176 + {
 177 +   unsigned int s;
 178 +   bitmap_iterator bs;
 179 +@@ -1227,7 +1259,7 @@ same_phi_alternatives (same_succ same_su
 180 +
 181 +       /* For all phis in bb, the phi alternatives for e1 and e2 need to have
 182 +        the same value.  */
 183 +-      if (!same_phi_alternatives_1 (succ, e1, e2))
 184 ++      if (!same_phi_alternatives_1 (succ, e1, e2, gvn_used))
 185 +       return false;
 186 +     }
 187 +
 188 +@@ -1301,6 +1333,7 @@ find_clusters_1 (same_succ same_succ)
 189 +   bitmap_iterator bi, bj;
 190 +   int nr_comparisons;
 191 +   int max_comparisons = PARAM_VALUE (PARAM_MAX_TAIL_MERGE_COMPARISONS);
 192 ++  bool gvn_used;
 193 +
 194 +   EXECUTE_IF_SET_IN_BITMAP (same_succ->bbs, 0, i, bi)
 195 +     {
 196 +@@ -1333,10 +1366,11 @@ find_clusters_1 (same_succ same_succ)
 197 +         if (!deps_ok_for_redirect (bb1, bb2))
 198 +           continue;
 199 +
 200 +-        if (!(same_phi_alternatives (same_succ, bb1, bb2)))
 201 ++        gvn_used = false;
 202 ++        if (!(same_phi_alternatives (same_succ, bb1, bb2, &gvn_used)))
 203 +           continue;
 204 +
 205 +-        find_duplicate (same_succ, bb1, bb2);
 206 ++        find_duplicate (same_succ, bb1, bb2, gvn_used);
 207 +         }
 208 +     }
 209 + }
 210 +--- gcc/testsuite/gcc.dg/pr52734.c
 211 ++++ gcc/testsuite/gcc.dg/pr52734.c
 212 +@@ -0,0 +1,35 @@
 213 ++/* { dg-do run } */
 214 ++/* { dg-options "-O2" } */
 215 ++
 216 ++int bbb = 0;
 217 ++
 218 ++int __attribute__((noinline,noclone)) aaa(void)
 219 ++{
 220 ++    ++bbb;
 221 ++    return 0;
 222 ++}
 223 ++
 224 ++int __attribute__((noinline,noclone)) ccc(void)
 225 ++{
 226 ++  int ddd;
 227 ++  /* bbb == 0 */
 228 ++  if (aaa())
 229 ++    return bbb;
 230 ++
 231 ++  /* bbb == 1 */
 232 ++  ddd = bbb;
 233 ++  /* bbb == ddd == 1 */
 234 ++  if (aaa ())
 235 ++    return 0;
 236 ++  /* bbb == 2, ddd == 1 */
 237 ++
 238 ++  return ddd;
 239 ++}
 240 ++
 241 ++int main(void)
 242 ++{
 243 ++    if (ccc() != 1)
 244 ++      __builtin_abort();
 245 ++    return 0;
 246 ++}
 247 ++