Re: C6X port 9/11: Allow defining attributes in terms of another

[Bernd Schmidt]

On 05/10/2011 03:47 PM, Bernd Schmidt wrote:
> I've found it useful to use a construct such as the following:
> 
> (define_attr "units64"
>   "unknown,d,d_addr,l,m,s,dl,ds,dls,ls"
>   (const_string "unknown"))
> 
> (define_attr "units64p"
>   "unknown,d,d_addr,l,m,s,dl,ds,dls,ls"
>   (attr "units64"))
> 
> to define one attribute in terms of another by default, allowing
> individual insn patterns to override the definition of "units64p" where
> necessary. This patch adds support for this in genattrtab.

Here's a new version, which emits casts to avoid C/C++ warnings when
compiled with --enable-werror-always.

Bootstrapped on i686-linux, and cross-compilers built for arm and c6x.
An i686-linux testrun is in progress.


Bernd

        * genattrtab.c (evaluate_eq_attr): Allow an attribute to be defined
        in terms of another.
        (write_attr_value): Write a cast if necessary.

Index: gcc/genattrtab.c
===================================================================
--- gcc/genattrtab.c.orig
+++ gcc/genattrtab.c
@@ -1916,6 +1916,37 @@ evaluate_eq_attr (rtx exp, struct attr_d
   rtx newexp;
   int i;
 
+  while (GET_CODE (value) == ATTR)
+    {
+      struct attr_value *av = NULL;
+
+      attr = find_attr (&XSTR (value, 0), 0);
+
+      if (insn_code_values)
+        {
+          struct attr_value_list *iv;
+          for (iv = insn_code_values[insn_code]; iv; iv = iv->next)
+            if (iv->attr == attr)
+              {
+                av = iv->av;
+                break;
+              }
+        }
+      else
+        {
+          struct insn_ent *ie;
+          for (av = attr->first_value; av; av = av->next)
+            for (ie = av->first_insn; ie; ie = ie->next)
+              if (ie->def->insn_code == insn_code)
+                goto got_av;
+        }
+      if (av)
+        {
+        got_av:
+          value = av->value;
+        }
+    }
+
   switch (GET_CODE (value))
     {
     case CONST_STRING:
@@ -4119,6 +4150,13 @@ write_attr_value (struct attr_desc *attr
     case ATTR:
       {
        struct attr_desc *attr2 = find_attr (&XSTR (value, 0), 0);
+       if (attr->enum_name)
+         printf ("(enum %s)", attr->enum_name);
+       else if (!attr->is_numeric)
+         printf ("(enum attr_%s)", attr->name);
+       else if (!attr2->is_numeric)
+         printf ("(int)");
+
        printf ("get_attr_%s (%s)", attr2->name,
                (attr2->is_const ? "" : "insn"));
       }