ada: Further optimize interface objects initialized with function calls

This further optimizes the usual case of (class-wide) interface objects that
are initialized with calls to functions whose result type is the type of the
objects (this is not necessary as any result type implementing the interface
would do) by avoiding a back-and-forth displacement of the objects' address.

This exposed a latent issue whereby the displacement was missing in the case
of a simple return statement whose expression is a call to a function whose
result type is a specific tagged type that needs finalization.

And, in order to avoid pessimizing the expanded code, this in turn required
avoiding to create temporaries for allocators by calling Remove_Side_Effects
up front, in the common cases when they are not necessary.

gcc/ada/

	* exp_ch3.adb (Expand_N_Object_Declaration): Do not generate a back-
	and-forth displacement of the object's address when using a renaming
	for an interface object with an expression of the same type.
	* exp_ch4.adb (Expand_Allocator_Expression): Do not remove the side
	effects of the expression up front for the simple allocators. Do not
	call the Adjust primitive if the expression is a function call.
	* exp_ch6.adb (Expand_Ctrl_Function_Call): Do not expand the call
	unnecessarily for a special return object.
	(Expand_Simple_Function_Return): Restore the displacement of the
	return object's address in the case where the expression is the call
	to a function whose result type is a type that needs finalization.
	* exp_util.adb (Expand_Subtype_From_Expr): Do not remove the side
	effects of the expression before calling Make_Subtype_From_Expr.
	(Make_CW_Equivalent_Type): If the expression has the tag of its type
	and this type has a uniform size, use 'Object_Size of this type in
	lieu of 'Size of the expression to compute the expression's size.

0 files changed, 0 insertions, 0 deletions