2005-05-25 Adrian Straetling <straetling@de.ibm.com>

	* loop-doloop.c: Include "target.h".
	  (doloop_valid_p): Move tests to function in targhooks.c.
	* target.h (struct gcc_target): New target hook
	  "insn_valid_within_doloop".
	* target-def.h: Define default value for "insn_valid_within_doloop".
	  (TARGET_INITIALIZER): Insert new target hook into initializer.
	* targhooks.c (default_insn_valid_within_doloop): New function.
	* targhooks.h (default_insn_valid_within_doloop): Declare.
	* hooks.c (hook_bool_rtx_true): New function.
	* hooks.h (hook_bool_rtx_true): Declare.
	* doc/tm.texi: Add documentation for new target hook.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@100143 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 7 insertions, 19 deletions

diff --git a/gcc/loop-doloop.c b/gcc/loop-doloop.c
index c6ef37e84d6..4a2bb8774ee 100644
--- a/gcc/loop-doloop.c
+++ b/gcc/loop-doloop.c
@@ -33,6 +33,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 #include "cfgloop.h"
 #include "output.h"
 #include "params.h"
+#include "target.h"
 
 /* This module is used to modify loops with a determinable number of
    iterations to use special low-overhead looping instructions.
@@ -187,27 +188,14 @@ doloop_valid_p (struct loop *loop, struct niter_desc *desc)
 	   insn != NEXT_INSN (BB_END (bb));
 	   insn = NEXT_INSN (insn))
 	{
-	  /* A called function may clobber any special registers required for
-	     low-overhead looping.  */
-	  if (CALL_P (insn))
-	    {
-	      if (dump_file)
-		fprintf (dump_file, "Doloop: Function call in loop.\n");
+	  /* Different targets have different necessities for low-overhead
+	     looping.  Call the back end for each instruction within the loop
+	     to let it decide whether the insn is valid.  */
+	  if (!targetm.insn_valid_within_doloop (insn))
+	  {
 	      result = false;
 	      goto cleanup;
-	    }
-
-	  /* Some targets (eg, PPC) use the count register for branch on table
-	     instructions.  ??? This should be a target specific check.  */
-	  if (JUMP_P (insn)
-	      && (GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
-		  || GET_CODE (PATTERN (insn)) == ADDR_VEC))
-	    {
-	      if (dump_file)
-		fprintf (dump_file, "Doloop: Computed branch in the loop.\n");
-	      result = false;
-	      goto cleanup;
-	    }
+	  }
 	}
     }
   result = true;