bitint: Handle complex types in build_bitint_stmt_ssa_conflicts [PR114425]

The task of the build_bitint_stmt_ssa_conflicts hook for
tree-ssa-coalesce.cc next to special casing the
multiplication/division/modulo is to ignore statements with
large/huge _BitInt lhs which isn't in names bitmap and on the
other side pretend all uses of the stmt are used in a later stmt
(single user of that SSA_NAME or perhaps single user of lhs of
the single user etc.) where the lowering will actually emit the
code.

Unfortunately the function wasn't handling COMPLEX_TYPE of the large/huge
BITINT_TYPE, while the FE doesn't really support such types, they are
used under the hood for __builtin_{add,sub,mul}_overflow{,_p}, they are
also present or absent from the names bitmap and should be treated the same.

Without this patch, the operands of .ADD_OVERFLOW were incorrectly pretended
to be used right in that call statement rather than on the cast stmt from
IMAGPART_EXPR of .ADD_OVERFLOW return value to some integral type.

2024-03-23  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/114425
	* gimple-lower-bitint.cc (build_bitint_stmt_ssa_conflicts): Handle
	_Complex large/huge _BitInt types like the large/huge _BitInt types.

	* gcc.dg/torture/bitint-67.c: New test.

2 files changed, 72 insertions, 28 deletions

diff --git a/gcc/gimple-lower-bitint.cc b/gcc/gimple-lower-bitint.cc
index 8c26800..6f13c65 100644
--- a/gcc/gimple-lower-bitint.cc
+++ b/gcc/gimple-lower-bitint.cc
@@ -5902,20 +5902,25 @@ build_bitint_stmt_ssa_conflicts (gimple *stmt, live_track *live,
   if (is_gimple_assign (stmt))
     {
       lhs = gimple_assign_lhs (stmt);
-      if (TREE_CODE (lhs) == SSA_NAME
-	  && TREE_CODE (TREE_TYPE (lhs)) == BITINT_TYPE
-	  && bitint_precision_kind (TREE_TYPE (lhs)) >= bitint_prec_large)
+      if (TREE_CODE (lhs) == SSA_NAME)
 	{
-	  if (!bitmap_bit_p (names, SSA_NAME_VERSION (lhs)))
-	    return;
-	  switch (gimple_assign_rhs_code (stmt))
+	  tree type = TREE_TYPE (lhs);
+	  if (TREE_CODE (type) == COMPLEX_TYPE)
+	    type = TREE_TYPE (type);
+	  if (TREE_CODE (type) == BITINT_TYPE
+	      && bitint_precision_kind (type) >= bitint_prec_large)
 	    {
-	    case MULT_EXPR:
-	    case TRUNC_DIV_EXPR:
-	    case TRUNC_MOD_EXPR:
-	      muldiv_p = true;
-	    default:
-	      break;
+	      if (!bitmap_bit_p (names, SSA_NAME_VERSION (lhs)))
+		return;
+	      switch (gimple_assign_rhs_code (stmt))
+		{
+		case MULT_EXPR:
+		case TRUNC_DIV_EXPR:
+		case TRUNC_MOD_EXPR:
+		  muldiv_p = true;
+		default:
+		  break;
+		}
 	    }
 	}
     }
@@ -5947,27 +5952,37 @@ build_bitint_stmt_ssa_conflicts (gimple *stmt, live_track *live,
 
   auto_vec<tree, 16> worklist;
   FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_USE)
-    if (TREE_CODE (TREE_TYPE (var)) == BITINT_TYPE
-	&& bitint_precision_kind (TREE_TYPE (var)) >= bitint_prec_large)
-      {
-	if (bitmap_bit_p (names, SSA_NAME_VERSION (var)))
-	  use (live, var);
-	else
-	  worklist.safe_push (var);
-      }
+    {
+      tree type = TREE_TYPE (var);
+      if (TREE_CODE (type) == COMPLEX_TYPE)
+	type = TREE_TYPE (type);
+      if (TREE_CODE (type) == BITINT_TYPE
+	  && bitint_precision_kind (type) >= bitint_prec_large)
+	{
+	  if (bitmap_bit_p (names, SSA_NAME_VERSION (var)))
+	    use (live, var);
+	  else
+	    worklist.safe_push (var);
+	}
+    }
 
   while (worklist.length () > 0)
     {
       tree s = worklist.pop ();
       FOR_EACH_SSA_TREE_OPERAND (var, SSA_NAME_DEF_STMT (s), iter, SSA_OP_USE)
-	if (TREE_CODE (TREE_TYPE (var)) == BITINT_TYPE
-	    && bitint_precision_kind (TREE_TYPE (var)) >= bitint_prec_large)
-	  {
-	    if (bitmap_bit_p (names, SSA_NAME_VERSION (var)))
-	      use (live, var);
-	    else
-	      worklist.safe_push (var);
-	  }
+	{
+	  tree type = TREE_TYPE (var);
+	  if (TREE_CODE (type) == COMPLEX_TYPE)
+	    type = TREE_TYPE (type);
+	  if (TREE_CODE (type) == BITINT_TYPE
+	      && bitint_precision_kind (type) >= bitint_prec_large)
+	    {
+	      if (bitmap_bit_p (names, SSA_NAME_VERSION (var)))
+		use (live, var);
+	      else
+		worklist.safe_push (var);
+	    }
+	}
     }
 
   if (muldiv_p)
diff --git a/gcc/testsuite/gcc.dg/torture/bitint-67.c b/gcc/testsuite/gcc.dg/torture/bitint-67.c
new file mode 100644
index 0000000..b5621e1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/bitint-67.c
@@ -0,0 +1,29 @@
+/* PR tree-optimization/114425 */
+/* { dg-do run { target bitint } } */
+/* { dg-options "-std=c23" } */
+/* { dg-skip-if "" { ! run_expensive_tests }  { "*" } { "-O0" "-O2" } } */
+/* { dg-skip-if "" { ! run_expensive_tests } { "-flto" } { "" } } */
+
+#if __BITINT_MAXWIDTH__ >= 2000
+_BitInt(8) a;
+_BitInt(300) b;
+_BitInt(2000) c;
+
+__attribute__((noipa)) unsigned
+foo (_BitInt(2000) d)
+{
+  int o = __builtin_add_overflow_p (d, 0, b);
+  _BitInt(2000) m = c * a;
+  unsigned u = m;
+  return u + o;
+}
+#endif
+
+int
+main ()
+{
+#if __BITINT_MAXWIDTH__ >= 2000
+  if (foo (0xfa7ac16f2613255eeb217e871c1f02221e26ce11f82d6a33206ec0ad5d4414722019933c0e2wb) != 1)
+    __builtin_abort ();
+#endif
+}