mips.c (mips16_optimize_gp): Delete.

	* config/mips/mips.c (mips16_optimize_gp): Delete.
	(mips_reorg): Don't call it.

From-SVN: r76623

2 files changed, 6 insertions, 223 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index feb30c8..bbeb017 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2004-01-26  Richard Sandiford  <rsandifo@redhat.com>
+
+	* config/mips/mips.c (mips16_optimize_gp): Delete.
+	(mips_reorg): Don't call it.
+
 2004-01-26  Michael Hayes  <m.hayes@elec.canterbury.ac.nz>
 
 	* config/c4x/c4x.md (addqi3_noclobber): Move up pecking order.
diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
index df338f7..4663ad4 100644
--- a/gcc/config/mips/mips.c
+++ b/gcc/config/mips/mips.c
@@ -267,7 +267,6 @@ static rtx mips_return_fpr_pair (enum machine_mode mode,
 static rtx mips16_gp_pseudo_reg (void);
 static void mips16_fp_args (FILE *, int, int);
 static void build_mips16_function_stub (FILE *);
-static void mips16_optimize_gp (void);
 static rtx add_constant	(struct constant **, rtx, enum machine_mode);
 static void dump_constants (struct constant *, rtx);
 static rtx mips_find_symbol (rtx);
@@ -8306,223 +8305,6 @@ build_mips16_call_stub (rtx retval, rtx fn, rtx arg_size, int fp_code)
   return 0;
 }
 
-/* This function looks through the code for a function, and tries to
-   optimize the usage of the $gp register.  We arrange to copy $gp
-   into a pseudo-register, and then let gcc's normal reload handling
-   deal with the pseudo-register.  Unfortunately, if reload choose to
-   put the pseudo-register into a call-clobbered register, it will
-   emit saves and restores for that register around any function
-   calls.  We don't need the saves, and it's faster to copy $gp than
-   to do an actual restore.  ??? This still means that we waste a
-   stack slot.
-
-   This is an optimization, and the code which gcc has actually
-   generated is correct, so we do not need to catch all cases.  */
-
-static void
-mips16_optimize_gp (void)
-{
-  rtx gpcopy, slot, insn;
-
-  /* Look through the instructions.  Set GPCOPY to the register which
-     holds a copy of $gp.  Set SLOT to the stack slot where it is
-     saved.  If we find an instruction which sets GPCOPY to anything
-     other than $gp or SLOT, then we can't use it.  If we find an
-     instruction which sets SLOT to anything other than GPCOPY, we
-     can't use it.  */
-
-  gpcopy = NULL_RTX;
-  slot = NULL_RTX;
-  for (insn = get_insns (); insn != NULL_RTX; insn = next_active_insn (insn))
-    {
-      rtx set;
-
-      if (! INSN_P (insn))
-	continue;
-
-      set = PATTERN (insn);
-
-      /* We know that all references to memory will be inside a SET,
-         because there is no other way to access memory on the mips16.
-         We don't have to worry about a PARALLEL here, because the
-         mips.md file will never generate them for memory references.  */
-      if (GET_CODE (set) != SET)
-	continue;
-
-      if (gpcopy == NULL_RTX
-	  && GET_CODE (SET_SRC (set)) == CONST
-	  && XEXP (SET_SRC (set), 0) == pic_offset_table_rtx
-	  && GET_CODE (SET_DEST (set)) == REG)
-	gpcopy = SET_DEST (set);
-      else if (slot == NULL_RTX
-	       && gpcopy != NULL_RTX
-	       && GET_CODE (SET_DEST (set)) == MEM
-	       && GET_CODE (SET_SRC (set)) == REG
-	       && REGNO (SET_SRC (set)) == REGNO (gpcopy))
-	{
-	  rtx base, offset;
-
-	  offset = const0_rtx;
-	  base = eliminate_constant_term (XEXP (SET_DEST (set), 0), &offset);
-	  if (GET_CODE (base) == REG
-	      && (REGNO (base) == STACK_POINTER_REGNUM
-		  || REGNO (base) == FRAME_POINTER_REGNUM))
-	    slot = SET_DEST (set);
-	}
-      else if (gpcopy != NULL_RTX
-	       && (GET_CODE (SET_DEST (set)) == REG
-		   || GET_CODE (SET_DEST (set)) == SUBREG)
-	       && reg_overlap_mentioned_p (SET_DEST (set), gpcopy)
-	       && (GET_CODE (SET_DEST (set)) != REG
-		   || REGNO (SET_DEST (set)) != REGNO (gpcopy)
-		   || ((GET_CODE (SET_SRC (set)) != CONST
-			|| XEXP (SET_SRC (set), 0) != pic_offset_table_rtx)
-		       && ! rtx_equal_p (SET_SRC (set), slot))))
-	break;
-      else if (slot != NULL_RTX
-	       && GET_CODE (SET_DEST (set)) == MEM
-	       && rtx_equal_p (SET_DEST (set), slot)
-	       && (GET_CODE (SET_SRC (set)) != REG
-		   || REGNO (SET_SRC (set)) != REGNO (gpcopy)))
-	break;
-    }
-
-  /* If we couldn't find a unique value for GPCOPY or SLOT, then try a
-     different optimization.  Any time we find a copy of $28 into a
-     register, followed by an add of a symbol_ref to that register, we
-     convert it to load the value from the constant table instead.
-     The copy and add will take six bytes, just as the load and
-     constant table entry will take six bytes.  However, it is
-     possible that the constant table entry will be shared.
-
-     This could be a peephole optimization, but I don't know if the
-     peephole code can call force_const_mem.
-
-     Using the same register for the copy of $28 and the add of the
-     symbol_ref is actually pretty likely, since the add instruction
-     requires the destination and the first addend to be the same
-     register.  */
-
-  if (insn != NULL_RTX || gpcopy == NULL_RTX || slot == NULL_RTX)
-    {
-#if 0
-      /* Used below in #if 0 area.  */
-      rtx next;
-#endif
-      /* This optimization is only reasonable if the constant table
-         entries are only 4 bytes.  */
-      if (Pmode != SImode)
-	return;
-
-#if 0
-  /* ??? FIXME.  Rewrite for new UNSPEC_RELOC stuff.  */
-      for (insn = get_insns (); insn != NULL_RTX; insn = next)
-	{
-	  rtx set1, set2;
-
-	  next = insn;
-	  do
-	    {
-	      next = NEXT_INSN (next);
-	    }
-	  while (next != NULL_RTX
-		 && (GET_CODE (next) == NOTE
-		     || (GET_CODE (next) == INSN
-			 && (GET_CODE (PATTERN (next)) == USE
-			     || GET_CODE (PATTERN (next)) == CLOBBER))));
-
-	  if (next == NULL_RTX)
-	    break;
-
-	  if (! INSN_P (insn))
-	    continue;
-
-	  if (! INSN_P (next))
-	    continue;
-
-	  set1 = PATTERN (insn);
-	  if (GET_CODE (set1) != SET)
-	    continue;
-	  set2 = PATTERN (next);
-	  if (GET_CODE (set2) != SET)
-	    continue;
-
-	  if (GET_CODE (SET_DEST (set1)) == REG
-	      && GET_CODE (SET_SRC (set1)) == CONST
-	      && XEXP (SET_SRC (set1), 0) == pic_offset_table_rtx
-	      && rtx_equal_p (SET_DEST (set1), SET_DEST (set2))
-	      && GET_CODE (SET_SRC (set2)) == PLUS
-	      && rtx_equal_p (SET_DEST (set1), XEXP (SET_SRC (set2), 0))
-	      && mips16_gp_offset_p (XEXP (SET_SRC (set2), 1))
-	      && GET_CODE (XEXP (XEXP (SET_SRC (set2), 1), 0)) == MINUS)
-	    {
-	      rtx sym;
-
-	      /* We've found a case we can change to load from the
-                 constant table.  */
-
-	      sym = XEXP (XEXP (XEXP (SET_SRC (set2), 1), 0), 0);
-	      if (GET_CODE (sym) != SYMBOL_REF)
-		abort ();
-	      emit_insn_after (gen_rtx (SET, VOIDmode, SET_DEST (set1),
-					force_const_mem (Pmode, sym)),
-			       next);
-
-	      PUT_CODE (insn, NOTE);
-	      NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
-	      NOTE_SOURCE_FILE (insn) = 0;
-
-	      PUT_CODE (next, NOTE);
-	      NOTE_LINE_NUMBER (next) = NOTE_INSN_DELETED;
-	      NOTE_SOURCE_FILE (next) = 0;
-	    }
-	}
-#endif
-
-      return;
-    }
-  /* We can safely remove all assignments to SLOT from GPCOPY, and
-     replace all assignments from SLOT to GPCOPY with assignments from
-     $28.  */
-
-  for (insn = get_insns (); insn != NULL_RTX; insn = next_active_insn (insn))
-    {
-      rtx set;
-
-      if (! INSN_P (insn))
-	continue;
-
-      set = PATTERN (insn);
-      if (GET_CODE (set) != SET)
-	continue;
-
-      if (GET_CODE (SET_DEST (set)) == MEM
-	  && rtx_equal_p (SET_DEST (set), slot)
-	  && GET_CODE (SET_SRC (set)) == REG
-	  && REGNO (SET_SRC (set)) == REGNO (gpcopy))
-	{
-	  PUT_CODE (insn, NOTE);
-	  NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
-	  NOTE_SOURCE_FILE (insn) = 0;
-	}
-      else if (GET_CODE (SET_DEST (set)) == REG
-	       && REGNO (SET_DEST (set)) == REGNO (gpcopy)
-	       && GET_CODE (SET_SRC (set)) == MEM
-	       && rtx_equal_p (SET_SRC (set), slot))
-	{
-	  enum machine_mode mode;
-	  rtx src;
-
-	  mode = GET_MODE (SET_DEST (set));
-	  src = gen_rtx_CONST (mode, pic_offset_table_rtx);
-	  emit_insn_after (gen_rtx_SET (VOIDmode, SET_DEST (set), src), insn);
-	  PUT_CODE (insn, NOTE);
-	  NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
-	  NOTE_SOURCE_FILE (insn) = 0;
-	}
-    }
-}
-
 /* We keep a list of constants we which we have to add to internal
    constant tables in the middle of large functions.  */
 
@@ -8971,11 +8753,7 @@ static void
 mips_reorg (void)
 {
   if (TARGET_MIPS16)
-    {
-      if (optimize)
-	mips16_optimize_gp ();
-      mips16_lay_out_constants ();
-    }
+    mips16_lay_out_constants ();
   else if (TARGET_EXPLICIT_RELOCS)
     {
       if (mips_flag_delayed_branch)