df.c (read_modify_subreg_p): Change from static to global.

        * df.c (read_modify_subreg_p): Change from static to global.
        * df.h (read_modify_subreg_p): Add prototype.
        * sched-deps.c (sched_analyze_1): Generate true dependency for
        strict_low_part, certain subregs and zero/sign_extract.

From-SVN: r64164

gcc/ChangeLog

+2003-03-11  Hartmut Penner  <hpenner@de.ibm.com>
+
+	* df.c (read_modify_subreg_p): Change from static to global.
+	* df.h (read_modify_subreg_p): Add prototype.
+	* sched-deps.c (sched_analyze_1): Generate true dependency for
+	strict_low_part, certain subregs and zero/sign_extract. 
+
 2003-03-11  Neil Booth  <neil@daikokuya.co.uk>
 
 	* Makefile.in: Update.

gcc/df.c

@@ -307,7 +307,6 @@ static void hybrid_search_sbitmap PARAMS ((basic_block, sbitmap *, sbitmap *,
 					   enum df_confluence_op,
 					   transfer_function_sbitmap,
 					   sbitmap, sbitmap, void *));
-static inline bool read_modify_subreg_p PARAMS ((rtx));
 
 
 /* Local memory allocation/deallocation routines.  */
@@ -885,7 +884,7 @@ df_ref_record (df, reg, loc, insn, ref_type, ref_flags)
 
 /* Return non-zero if writes to paradoxical SUBREGs, or SUBREGs which
    are too narrow, are read-modify-write.  */
-static inline bool
+bool
 read_modify_subreg_p (x)
      rtx x;
 {

gcc/df.h

@@ -353,3 +353,4 @@ extern void iterative_dataflow_bitmap PARAMS ((bitmap *, bitmap *, bitmap *,
 					       enum df_confluence_op, 
 					       transfer_function_bitmap, 
 					       int *, void *));
+extern bool read_modify_subreg_p PARAMS ((rtx));

gcc/sched-deps.c

@@ -42,6 +42,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 #include "sched-int.h"
 #include "params.h"
 #include "cselib.h"
+#include "df.h"
 
 extern char *reg_known_equiv_p;
 extern rtx *reg_known_value;
@@ -468,6 +469,19 @@ sched_analyze_1 (deps, x, insn)
   while (GET_CODE (dest) == STRICT_LOW_PART || GET_CODE (dest) == SUBREG
 	 || GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SIGN_EXTRACT)
     {
+      if (GET_CODE (dest) == STRICT_LOW_PART
+	 || GET_CODE (dest) == ZERO_EXTRACT
+	 || GET_CODE (dest) == SIGN_EXTRACT
+	 || read_modify_subreg_p (dest))
+        {
+	  /* These both read and modify the result.  We must handle 
+             them as writes to get proper dependencies for following
+             instructions.  We must handle them as reads to get proper
+             dependencies from this to previous instructions.
+             Thus we need to call sched_analyze_2. */
+
+	  sched_analyze_2 (deps, XEXP (dest, 0), insn);  
+	}
       if (GET_CODE (dest) == ZERO_EXTRACT || GET_CODE (dest) == SIGN_EXTRACT)
 	{
 	  /* The second and third arguments are values read by this insn.  */