[PATCH][varmap] Preserve bitmaps on SETs in the face of splitters

[Richard Guenther <rguenther@suse.de>]

Applied to var-mappings-branch.

Richard.


2007-11-07  Michael Matz  <matz@suse.de>

	* emit-rtl.c (move_xbitmap): New helper.
	(try_split): Preserve bitmap of names from splitters.

	* gcc.dg/tree-ssa/vars-2.c: New testcase.

Index: var-mappings-branch/gcc/emit-rtl.c
===================================================================
*** var-mappings-branch.orig/gcc/emit-rtl.c	2007-11-12 17:51:42.000000000 +0100
--- var-mappings-branch/gcc/emit-rtl.c	2007-11-12 17:55:40.000000000 +0100
*************** mark_label_nuses (rtx x)
*** 3185,3190 ****
--- 3185,3204 ----
  }
  
  \f
+ static void
+ move_xbitmap (rtx x, const_rtx cset, void *data)
+ {
+   rtx orig_set = (rtx)data;
+   rtx set = (rtx)cset;
+   if (GET_CODE (set) == CLOBBER)
+     return;
+   if (!reg_overlap_mentioned_p (x, SET_DEST (orig_set)))
+     return;
+   if (XBITMAP (set, 2))
+     return;
+   XBITMAP (set, 2) = XBITMAP (orig_set, 2);
+ }
+ 
  /* Try splitting insns that can be split for better scheduling.
     PAT is the pattern which might split.
     TRIAL is the insn providing PAT.
*************** try_split (rtx pat, rtx trial, int last)
*** 3368,3373 ****
--- 3382,3416 ----
  	}
      }
  
+   if (GET_CODE (pat) == SET && XBITMAP (pat, 2))
+     {
+       insn = insn_last;
+       while (insn != NULL_RTX)
+         {
+ 	  if (INSN_P (insn))
+ 	    note_stores (PATTERN (insn), move_xbitmap, pat);
+ 	  insn = PREV_INSN (insn);
+         }
+     }
+   else if (GET_CODE (pat) == PARALLEL)
+     {
+       int i;
+       for (i = 0; i < XVECLEN (pat, 0); i++)
+         if (GET_CODE (XVECEXP (pat, 0, i)) == SET
+ 	    && XBITMAP (XVECEXP (pat, 0, i), 2))
+           {
+ 	    rtx set = XVECEXP (pat, 0, i);
+ 	    insn = insn_last;
+ 	    while (insn != NULL_RTX)
+ 	      {
+ 	        if (INSN_P (insn))
+ 		  note_stores (PATTERN (insn), move_xbitmap, set);
+ 		insn = PREV_INSN (insn);
+ 	      }
+           }
+     }
+ 
+ 
    tem = emit_insn_after_setloc (seq, trial, INSN_LOCATOR (trial));
  
    delete_insn (trial);
Index: var-mappings-branch/gcc/testsuite/gcc.dg/tree-ssa/vars-2.c
===================================================================
*** /dev/null	1970-01-01 00:00:00.000000000 +0000
--- var-mappings-branch/gcc/testsuite/gcc.dg/tree-ssa/vars-2.c	2007-11-12 17:55:40.000000000 +0100
***************
*** 0 ****
--- 1,21 ----
+ /* { dg-do compile } */
+ /* { dg-options "-O -g -fvar-tracking -fdump-tree-final_cleanup-vars -fdump-rtl-vartrack" } */
+ 
+ /* In this test we want to keep the name "j" associated with
+    the expression "i * 2" passed to the inlined function "bar"
+    even in the presence of RTL splitters.  */
+ 
+ static int bar(int j)
+ {
+   return j;
+ }
+ int l;
+ int foo(int i)
+ {
+   l = bar(i*2);
+   return l;
+ }
+ 
+ /* { dg-final { scan-tree-dump "i \\\* 2 E{ j }" "final_cleanup" } } */
+ /* { dg-final { scan-rtl-dump "\\\[orig:.* j \\\]" "vartrack" } } */
+ /* { dg-final { cleanup-tree-dump "final_cleanup" } } */