dse.c (find_shift_sequence): Reinstate "<= UNITS_PER_WORD" condition.

gcc/
	* dse.c (find_shift_sequence): Reinstate "<= UNITS_PER_WORD" condition.
	* var-tracking.c (micro_operation_def): Update comment on u.loc.
	(mode_for_reg_attrs, var_lowpart): New functions.
	(add_uses): Consider recording a lowpart of LOC for MO_USE.
	(add_stores): Likewise MO_SET and MO_COPY.  If the source of a set
	or copy is known, set LOC to the SET that performs the set, instead
	of the destination.
	(find_src_status, find_src_set_src): Remove LOC parameter.
	Replace INSN with the source value.
	(compute_bb_dataflow, emit_notes_in_bb): Check for a SET u.loc when
	handling MO_SET and MO_COPY.  Update the calls to find_src_status
	and find_src_set_src.

From-SVN: r129269

gcc/ChangeLog

+2007-10-12  Richard Sandiford  <rsandifo@nildram.co.uk>
+
+	* dse.c (find_shift_sequence): Reinstate "<= UNITS_PER_WORD" condition.
+	* var-tracking.c (micro_operation_def): Update comment on u.loc.
+	(mode_for_reg_attrs, var_lowpart): New functions.
+	(add_uses): Consider recording a lowpart of LOC for MO_USE.
+	(add_stores): Likewise MO_SET and MO_COPY.  If the source of a set
+	or copy is known, set LOC to the SET that performs the set, instead
+	of the destination.
+	(find_src_status, find_src_set_src): Remove LOC parameter.
+	Replace INSN with the source value.
+	(compute_bb_dataflow, emit_notes_in_bb): Check for a SET u.loc when
+	handling MO_SET and MO_COPY.  Update the calls to find_src_status
+	and find_src_set_src.
+
 2007-10-12  Nathan Froyd  <froydnj@codesourcery.com>
 
 	PR 11001

gcc/dse.c

@@ -1415,7 +1415,7 @@ find_shift_sequence (rtx read_reg,
      justify the value we want to read but is available in one insn on
      the machine.  */
 
-  for (; access_size < UNITS_PER_WORD; access_size *= 2)
+  for (; access_size <= UNITS_PER_WORD; access_size *= 2)
     {
       rtx target, new_reg, shift_seq, insn;
       enum machine_mode new_mode;