Fix IdentityExp comparison for complex floats

https://bugzilla.gdcproject.org/show_bug.cgi?id=309

gcc/d/expr.cc

@@ -255,6 +255,24 @@ class ExprVisitor : public Visitor
     this->result_ = build_condition (build_ctype (e->type), cond, t1, t2);
   }
 
+  /* Helper function for floating point identity comparison. Compare
+     only well-defined bits, ignore padding (e.g. for X86 80bit real).  */
+
+  static tree build_float_identity (tree_code code, tree e1, tree e2)
+  {
+    /* For floating-point values, identity is defined as the bits in the
+       operands being identical.  */
+    tree t1 = d_save_expr (e1);
+    tree t2 = d_save_expr (e2);
+
+    tree tmemcmp = builtin_decl_explicit (BUILT_IN_MEMCMP);
+    tree size = size_int (TYPE_PRECISION (TREE_TYPE (t1)) / BITS_PER_UNIT);
+
+    tree result = build_call_expr (tmemcmp, 3, build_address (t1),
+				   build_address (t2), size);
+    return build_boolop (code, result, integer_zero_node);
+  }
+
   /* Build an identity comparison expression.  Operands go through the
      usual conversions to bring them to a common type before comparison.
      The result type is bool.  */
@@ -275,19 +293,27 @@ class ExprVisitor : public Visitor
 	this->result_ = d_convert (build_ctype (e->type),
 				   build_boolop (code, t1, t2));
       }
-    else if (tb1->isfloating () && tb1->ty != Tvector)
+    else if (tb1->iscomplex () && tb1->ty != Tvector)
       {
-	/* For floating-point values, identity is defined as the bits in the
-	   operands being identical.  */
-	tree t1 = d_save_expr (build_expr (e->e1));
-	tree t2 = d_save_expr (build_expr (e->e2));
+	tree e1 = build_expr (e->e1);
+	tree e2 = build_expr (e->e2);
+	tree re1 = real_part (e1);
+	tree im1 = imaginary_part (e1);
+	tree re2 = real_part (e2);
+	tree im2 = imaginary_part (e2);
 
-	tree tmemcmp = builtin_decl_explicit (BUILT_IN_MEMCMP);
-	tree size = size_int (TYPE_PRECISION (TREE_TYPE (t1)) / BITS_PER_UNIT);
+	tree req = build_float_identity (code, re1, re2);
+	tree ieq = build_float_identity (code, im1, im2);
 
-	tree result = build_call_expr (tmemcmp, 3, build_address (t1),
-				       build_address (t2), size);
-	this->result_ = build_boolop (code, result, integer_zero_node);
+	if (code == EQ_EXPR)
+	  this->result_ = build_boolop (TRUTH_ANDIF_EXPR, req, ieq);
+	else
+	  this->result_ = build_boolop (TRUTH_ORIF_EXPR, req, ieq);
+      }
+    else if (tb1->isfloating () && tb1->ty != Tvector)
+      {
+	this->result_ = build_float_identity (code, build_expr (e->e1),
+					      build_expr (e->e2));
       }
     else if (tb1->ty == Tstruct)
       {

gcc/testsuite/gdc.dg/runnable.d

@@ -1533,6 +1533,27 @@ void test286()
         assert(0);
 }
 
+/******************************************/
+// https://bugzilla.gdcproject.org/show_bug.cgi?id=309
+
+void test309()
+{
+    creal f1 = +0.0 + 0.0i;
+    creal f2 = +0.0 - 0.0i;
+    creal f3 = -0.0 + 0.0i;
+    creal f4 = +0.0 + 0.0i;
+
+    assert(f1 !is f2);
+    assert(f1 !is f3);
+    assert(f2 !is f3);
+    assert(f1 is f4);
+
+    assert(!(f1 is f2));
+    assert(!(f1 is f3));
+    assert(!(f2 is f3));
+    assert(!(f1 !is f4));
+}
+
 /******************************************/
 
 void main()
@@ -1570,6 +1591,7 @@ void main()
     test273();
     test285();
     test286();
+    test309();
 
     printf("Success!\n");
 }