reload.c: (find_reloads): Skip alternatives according to the "enabled" attribute.

2008-05-27  Andreas Krebbel  <krebbel1@de.ibm.com>

	* reload.c: (find_reloads): Skip alternatives according to the
	"enabled" attribute. Constify the constraint variable.
	* recog.c (get_attr_enabled): Add default implementation.
	(extract_insn): Set the alternative_enabled_p array
	in the recog_data struct.
	(preprocess_constraints, constrain_operands): Skip
	alternatives according to the "enabled" attribute
	* recog.h (struct recog_data): New field alternative_enabled_p.
	(skip_alternative): New inline function.
	* regclass.c: (record_operand_costs): Check the "enabled"
	attribute.
	(record_reg_classes): Skip alternative according to the
	"enabled" attribute.

	* doc/md.texi: Add documention for the "enabled" attribute.

From-SVN: r136012

1 files changed, 19 insertions, 0 deletions

diff --git a/gcc/recog.h b/gcc/recog.h
index a7e22e6e349..6a2a2caf1da 100644
--- a/gcc/recog.h
+++ b/gcc/recog.h
@@ -143,6 +143,19 @@ recog_memoized (rtx insn)
 }
 #endif
 
+/* Skip chars until the next ',' or the end of the string.  This is
+   useful to skip alternatives in a constraint string.  */
+static inline const char *
+skip_alternative (const char *p)
+{
+  const char *r = p;
+  while (*r != '\0' && *r != ',')
+    r++;
+  if (*r == ',')
+    r++;
+  return r;
+}
+
 /* Nonzero means volatile operands are recognized.  */
 extern int volatile_ok;
 
@@ -202,6 +215,12 @@ struct recog_data
   /* The number of alternatives in the constraints for the insn.  */
   char n_alternatives;
 
+  /* Specifies whether an insn alternative is enabled using the
+     `enabled' attribute in the insn pattern definition.  For back
+     ends not using the `enabled' attribute the array fields are
+     always set to `true' in expand_insn.  */
+  bool alternative_enabled_p [MAX_RECOG_ALTERNATIVES];
+
   /* In case we are caching, hold insn data was generated for.  */
   rtx insn;
 };