gcc/ChangeLog:

PR debug/42630
* loop-unroll.c (referenced_in_one_insn_in_loop_p): Count debug
uses in new incoming argument.  Free body.
(reset_debug_uses_in_loop): New.
(analyze_insn_to_expand_var): Call the latter if the former found
anything.  Fix whitespace.  Reject invalid dest overlaps before
going through all insns in the loop.
gcc/testsuite/ChangeLog:
PR debug/42630
* gcc.dg/pr42630.c: New.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@155764 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e93c9f1..b386622 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,15 @@
 2010-01-09  Alexandre Oliva  <aoliva@redhat.com>
 
+       PR debug/42630
+       * loop-unroll.c (referenced_in_one_insn_in_loop_p): Count debug
+       uses in new incoming argument.  Free body.
+       (reset_debug_uses_in_loop): New.
+       (analyze_insn_to_expand_var): Call the latter if the former found
+       anything.  Fix whitespace.  Reject invalid dest overlaps before
+       going through all insns in the loop.
+
+2010-01-09  Alexandre Oliva  <aoliva@redhat.com>
+
        PR debug/42629
        * haifa-sched.c (dying_use_p): Debug insns don't count.
 

diff --git a/gcc/loop-unroll.c b/gcc/loop-unroll.c
index 6b7fe8a..231d12d 100644 (file)
--- a/gcc/loop-unroll.c
+++ b/gcc/loop-unroll.c
@@ -1,5 +1,5 @@
 /* Loop unrolling and peeling.
-   Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008
+   Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008, 2010
    Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -142,7 +142,7 @@ static void opt_info_start_duplication (struct opt_info *);
 static void apply_opt_in_copies (struct opt_info *, unsigned, bool, bool);
 static void free_opt_info (struct opt_info *);
 static struct var_to_expand *analyze_insn_to_expand_var (struct loop*, rtx);
-static bool referenced_in_one_insn_in_loop_p (struct loop *, rtx);
+static bool referenced_in_one_insn_in_loop_p (struct loop *, rtx, int *);
 static struct iv_to_split *analyze_iv_to_split_insn (rtx);
 static void expand_var_during_unrolling (struct var_to_expand *, rtx);
 static void insert_var_expansion_initialization (struct var_to_expand *,
@@ -1525,10 +1525,13 @@ ve_info_eq (const void *ivts1, const void *ivts2)
   return i1->insn == i2->insn;
 }
 
-/* Returns true if REG is referenced in one insn in LOOP.  */
+/* Returns true if REG is referenced in one nondebug insn in LOOP.
+   Set *DEBUG_USES to the number of debug insns that reference the
+   variable.  */
 
 bool
-referenced_in_one_insn_in_loop_p (struct loop *loop, rtx reg)
+referenced_in_one_insn_in_loop_p (struct loop *loop, rtx reg,
+                                 int *debug_uses)
 {
   basic_block *body, bb;
   unsigned i;
@@ -1541,14 +1544,45 @@ referenced_in_one_insn_in_loop_p (struct loop *loop, rtx reg)
       bb = body[i];
 
       FOR_BB_INSNS (bb, insn)
-      {
-        if (rtx_referenced_p (reg, insn))
-          count_ref++;
-      }
+       if (!rtx_referenced_p (reg, insn))
+         continue;
+       else if (DEBUG_INSN_P (insn))
+         ++*debug_uses;
+       else if (++count_ref > 1)
+         break;
     }
+  free (body);
   return (count_ref  == 1);
 }
 
+/* Reset the DEBUG_USES debug insns in LOOP that reference REG.  */
+
+static void
+reset_debug_uses_in_loop (struct loop *loop, rtx reg, int debug_uses)
+{
+  basic_block *body, bb;
+  unsigned i;
+  rtx insn;
+
+  body = get_loop_body (loop);
+  for (i = 0; debug_uses && i < loop->num_nodes; i++)
+    {
+      bb = body[i];
+
+      FOR_BB_INSNS (bb, insn)
+       if (!DEBUG_INSN_P (insn) || !rtx_referenced_p (reg, insn))
+         continue;
+       else
+         {
+           validate_change (insn, &INSN_VAR_LOCATION_LOC (insn),
+                            gen_rtx_UNKNOWN_VAR_LOC (), 0);
+           if (!--debug_uses)
+             break;
+         }
+    }
+  free (body);
+}
+
 /* Determine whether INSN contains an accumulator
    which can be expanded into separate copies,
    one for each copy of the LOOP body.
@@ -1579,6 +1613,7 @@ analyze_insn_to_expand_var (struct loop *loop, rtx insn)
   struct var_to_expand *ves;
   enum machine_mode mode1, mode2;
   unsigned accum_pos;
+  int debug_uses = 0;
 
   set = single_set (insn);
   if (!set)
@@ -1624,15 +1659,15 @@ analyze_insn_to_expand_var (struct loop *loop, rtx insn)
      the expansions at the end of the computation will yield wrong results
      for (x = something - x) thus avoid using it in that case.  */
   if (accum_pos == 1
-    && GET_CODE (src) == MINUS)
+      && GET_CODE (src) == MINUS)
    return NULL;
 
-  something = (accum_pos == 0)? op2 : op1;
+  something = (accum_pos == 0) ? op2 : op1;
 
-  if (!referenced_in_one_insn_in_loop_p (loop, dest))
+  if (rtx_referenced_p (dest, something))
     return NULL;
 
-  if (rtx_referenced_p (dest, something))
+  if (!referenced_in_one_insn_in_loop_p (loop, dest, &debug_uses))
     return NULL;
 
   mode1 = GET_MODE (dest);
@@ -1650,6 +1685,17 @@ analyze_insn_to_expand_var (struct loop *loop, rtx insn)
     fprintf (dump_file, "\n");
   }
 
+  if (debug_uses)
+    /* Instead of resetting the debug insns, we could replace each
+       debug use in the loop with the sum or product of all expanded
+       accummulators.  Since we'll only know of all expansions at the
+       end, we'd have to keep track of which vars_to_expand a debug
+       insn in the loop references, take note of each copy of the
+       debug insn during unrolling, and when it's all done, compute
+       the sum or product of each variable and adjust the original
+       debug insn and each copy thereof.  What a pain!  */
+    reset_debug_uses_in_loop (loop, dest, debug_uses);
+
   /* Record the accumulator to expand.  */
   ves = XNEW (struct var_to_expand);
   ves->insn = insn;

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 4d62e32..f9074e3 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,10 @@
 2010-01-09  Alexandre Oliva  <aoliva@redhat.com>
 
+       PR debug/42630
+       * gcc.dg/pr42630.c: New.
+
+2010-01-09  Alexandre Oliva  <aoliva@redhat.com>
+
        PR debug/42629
        * gcc.dg/pr42629.c: New.
 

diff --git a/gcc/testsuite/gcc.dg/pr42630.c b/gcc/testsuite/gcc.dg/pr42630.c
new file mode 100644 (file)
index 0000000..34543da
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr42630.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-O1 -fvariable-expansion-in-unroller -funroll-loops -fcompare-debug" } */
+
+int sum(int *buf, int len)
+{
+  int s = 0;
+  while (--len > 0) s += *buf++;
+  return s;
+}