re PR rtl-optimization/13041 (linux-2.6/sound/core/oss/rate.c miscompiled)

	PR optimization/13041
	* final.c (frame_pointer_needed): Fix comment.
	* reload1.c (reload): Decrease alignment of the frame
	pointer if it was used for register allocation.

From-SVN: r73978

gcc/ChangeLog

 2003-11-27  Eric Botcazou  <ebotcazou@libertysurf.fr>
 
+	PR optimization/13041
+	* final.c (frame_pointer_needed): Fix comment.
+	* reload1.c (reload): Decrease alignment of the frame
+	pointer if it was used for register allocation.
+
+2003-11-27  Eric Botcazou  <ebotcazou@libertysurf.fr>
+
 	PR target/12900
 	* reg-stack (move_for_stack_reg): New prototype.  Return
 	whether a control flow insn was deleted.

gcc/final.c

@@ -171,8 +171,8 @@ CC_STATUS cc_prev_status;
 char regs_ever_live[FIRST_PSEUDO_REGISTER];
 
 /* Nonzero means current function must be given a frame pointer.
-   Set in stmt.c if anything is allocated on the stack there.
-   Set in reload1.c if anything is allocated on the stack there.  */
+   Initialized in function.c to 0.  Set only in reload1.c as per
+   the needs of the function.  */
 
 int frame_pointer_needed;
 

gcc/reload1.c

@@ -1241,6 +1241,14 @@ reload (rtx first, int global)
      by this, so unshare everything here.  */
   unshare_all_rtl_again (first);
 
+#ifdef STACK_BOUNDARY
+  /* init_emit has set the alignment of the hard frame pointer
+     to STACK_BOUNDARY.  It is very likely no longer valid if
+     the hard frame pointer was used for register allocation.  */
+  if (!frame_pointer_needed)
+    REGNO_POINTER_ALIGN (HARD_FRAME_POINTER_REGNUM) = BITS_PER_UNIT;
+#endif
+
   return failure;
 }