PATCH: type attributes influence other types

[Andrew Haley]

> Date: Tue, 7 Sep 99 11:46:36 EDT
> From: kenner@vlsi1.ultra.nyu.edu (Richard Kenner)
> 
>     In testing I discovered that when compiling builtin functions gcc
>     assumes that alignment is *not* part of a function's type.  Here is an
>     amended patch.
> 
> Well that's true, but I'd think that if two function types had
> different TYPE_ALIGN values, something odd were going on.  Can you say
> more about this?

It's because build_function_type() does this:

  t = type_hash_canon (hashcode, t);

  if (TYPE_SIZE (t) == 0)
    layout_type (t);

Now, when a builtin is first defined, build_function_type() is called,
which calls type_hash_canon() which installs the builtin's type in the
hash table.  Later on when the front end parses a call to a builtin,
it calls build_function_type(), which calls type_hash_canon(), which
uses type_hash_lookup() to see if the type is already in the hash
table.  It does this *before* calling layout_type(), so the alignment
field of the function's type hasn't been set, so type_hash_lookup()
fails.

I suppose that we could solve this by ensuring that layout_type() is
always called before type_hash_lookup() ?

Andrew.