Revert:

	2017-03-17  Bernd Schmidt  <bschmidt@redhat.com>

	* combine.c (record_used_regs): New static function.
	(try_combine): Handle situations where there is an additional
	instruction between I2 and I3 which needs to have a LOG_LINK
	updated.

	Revert:
	2017-03-17  Jim Wilson  <jim.wilson@linaro.org>

	* combine.c (try_combine): Delete redundant i1 test.  Call
	prev_nonnote_nondebug_insn instead of prev_nonnote_insn.

From-SVN: r246296

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4b45637..55e9bc8 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,19 @@
+2017-03-20  Segher Boessenkool  <segher@kernel.crashing.org>
+
+       Revert:
+       2017-03-17  Bernd Schmidt  <bschmidt@redhat.com>
+
+       * combine.c (record_used_regs): New static function.
+       (try_combine): Handle situations where there is an additional
+       instruction between I2 and I3 which needs to have a LOG_LINK
+       updated.
+
+       Revert:
+       2017-03-17  Jim Wilson  <jim.wilson@linaro.org>
+
+       * combine.c (try_combine): Delete redundant i1 test.  Call
+       prev_nonnote_nondebug_insn instead of prev_nonnote_insn.
+
 2017-03-20  Aaron Sawdey  <acsawdey@linux.vnet.ibm.com>
 
        PR target/80083

diff --git a/gcc/combine.c b/gcc/combine.c
index 463737f..66215a6 100644 (file)
--- a/gcc/combine.c
+++ b/gcc/combine.c
@@ -2559,57 +2559,6 @@ can_split_parallel_of_n_reg_sets (rtx_insn *insn, int n)
   return true;
 }
 
-/* Set up a set of registers used in an insn.  Called through note_uses,
-   arguments as described for that function.  */
-
-static void
-record_used_regs (rtx *xptr, void *data)
-{
-  bitmap set = (bitmap)data;
-  int i, j;
-  enum rtx_code code;
-  const char *fmt;
-  rtx x = *xptr;
-
-  /* repeat is used to turn tail-recursion into iteration since GCC
-     can't do it when there's no return value.  */
- repeat:
-  if (x == 0)
-    return;
-
-  code = GET_CODE (x);
-  if (REG_P (x))
-    {
-      unsigned regno = REGNO (x);
-      unsigned end_regno = END_REGNO (x);
-      while (regno < end_regno)
-       bitmap_set_bit (set, regno++);
-      return;
-    }
-
-  /* Recursively scan the operands of this expression.  */
-
-  for (i = GET_RTX_LENGTH (code) - 1, fmt = GET_RTX_FORMAT (code); i >= 0; i--)
-    {
-      if (fmt[i] == 'e')
-       {
-         /* If we are about to do the last recursive call
-            needed at this level, change it into iteration.
-            This function is called enough to be worth it.  */
-         if (i == 0)
-           {
-             x = XEXP (x, 0);
-             goto repeat;
-           }
-
-         record_used_regs (&XEXP (x, i), data);
-       }
-      else if (fmt[i] == 'E')
-       for (j = 0; j < XVECLEN (x, i); j++)
-         record_used_regs (&XVECEXP (x, i, j), data);
-    }
-}
-
 /* Try to combine the insns I0, I1 and I2 into I3.
    Here I0, I1 and I2 appear earlier than I3.
    I0 and I1 can be zero; then we combine just I2 into I3, or I1 and I2 into
@@ -2793,26 +2742,6 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
 
   added_links_insn = 0;
 
-  /* For combinations that may result in two insns, we have to gather
-     some extra information about registers used, so that we can
-     update all relevant LOG_LINKS later.  */
-  auto_bitmap i2_regset, i3_regset, links_regset;
-  if (i1)
-    {
-      note_uses (&PATTERN (i2), record_used_regs, (bitmap)i2_regset);
-      note_uses (&PATTERN (i3), record_used_regs, (bitmap)i3_regset);
-      insn_link *ll;
-      FOR_EACH_LOG_LINK (ll, i3)
-       bitmap_set_bit (links_regset, ll->regno);
-      FOR_EACH_LOG_LINK (ll, i2)
-       bitmap_set_bit (links_regset, ll->regno);
-      FOR_EACH_LOG_LINK (ll, i1)
-       bitmap_set_bit (links_regset, ll->regno);
-      if (i0)
-       FOR_EACH_LOG_LINK (ll, i0)
-         bitmap_set_bit (links_regset, ll->regno);
-    }
-
   /* First check for one important special case that the code below will
      not handle.  Namely, the case where I1 is zero, I2 is a PARALLEL
      and I3 is a SET whose SET_SRC is a SET_DEST in I2.  In that case,
@@ -4122,33 +4051,6 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
       return 0;
     }
 
-  auto_bitmap new_regs_in_i2;
-  if (newi2pat)
-    {
-      /* We need to discover situations where we introduce a use of a
-        register into I2, where none of the existing LOG_LINKS contain
-        a reference to it.  This can happen if previously I3 referenced
-        the reg, and there is an additional use between I2 and I3.  We
-        must remove the LOG_LINKS entry from that additional use and
-        distribute it along with our own ones.  */
-       note_uses (&newi2pat, record_used_regs, (bitmap)new_regs_in_i2);
-       bitmap_and_compl_into (new_regs_in_i2, i2_regset);
-       bitmap_and_compl_into (new_regs_in_i2, links_regset);
-
-       /* Here, we first look for situations where a hard register use
-          moved, and just give up.  This should happen approximately
-          never, and it's not worth it to deal with possibilities like
-          multi-word registers.  Later, when fixing up LOG_LINKS, we
-          deal with the case where a pseudo use moved.  */
-       if (!bitmap_empty_p (new_regs_in_i2)
-           && prev_nonnote_nondebug_insn (i3) != i2
-           && bitmap_first_set_bit (new_regs_in_i2) < FIRST_PSEUDO_REGISTER)
-         {
-           undo_all ();
-           return 0;
-         }
-    }
-
   if (MAY_HAVE_DEBUG_INSNS)
     {
       struct undo *undo;
@@ -4591,45 +4493,6 @@ try_combine (rtx_insn *i3, rtx_insn *i2, rtx_insn *i1, rtx_insn *i0,
                            NULL_RTX, NULL_RTX, NULL_RTX);
       }
 
-    if (newi2pat)
-      {
-       bitmap_iterator iter;
-       unsigned int i;
-
-       /* See comments above where we calculate the bitmap.  */
-       EXECUTE_IF_SET_IN_BITMAP ((bitmap)new_regs_in_i2,
-                                 LAST_VIRTUAL_REGISTER, i, iter)
-         {
-           rtx reg = regno_reg_rtx[i];
-           rtx_insn *other;
-           for (other = NEXT_INSN (i2); other != i3; other = NEXT_INSN (other))
-             if (NONDEBUG_INSN_P (other)
-                 && (reg_overlap_mentioned_p (reg, PATTERN (other))
-                     || (CALL_P (other) && find_reg_fusage (other, USE, reg))))
-               {
-                 if (dump_file)
-                   fprintf (dump_file,
-                            "found extra use of reg %d at insn %d\n", i,
-                            INSN_UID (other));
-                 insn_link **plink;
-                 for (plink = &LOG_LINKS (other);
-                      *plink;
-                      plink = &(*plink)->next)
-                   {
-                     insn_link *link = *plink;
-                     if (link->regno == i)
-                       {
-                         *plink = link->next;
-                         link->next = i3links;
-                         i3links = link;
-                         break;
-                       }
-                   }
-                 break;
-               }
-         }
-      }
-
     distribute_links (i3links);
     distribute_links (i2links);
     distribute_links (i1links);