[71/77] Use opt_scalar_mode for mode iterators

This patch uses opt_scalar_mode when iterating over scalar modes.

2017-08-30  Richard Sandiford  <richard.sandiford@linaro.org>
	    Alan Hayward  <alan.hayward@arm.com>
	    David Sherwood  <david.sherwood@arm.com>

gcc/
	* coretypes.h (opt_scalar_mode): New typedef.
	* gdbhooks.py (build_pretty_printers): Handle it.
	* machmode.h (mode_iterator::get_2xwider): Add overload for
	opt_mode<T>.
	* emit-rtl.c (init_emit_once): Use opt_scalar_mode when iterating
	over scalar modes.
	* expr.c (convert_mode_scalar): Likewise.
	* omp-low.c (omp_clause_aligned_alignment): Likewise.
	* optabs.c (expand_float): Likewise.
	(expand_fix): Likewise.
	* tree-vect-stmts.c (vectorizable_conversion): Likewise.

gcc/c-family/
	* c-common.c (c_common_fixed_point_type_for_size): Use opt_scalar_mode
	for the mode iterator.

Co-Authored-By: Alan Hayward <alan.hayward@arm.com>
Co-Authored-By: David Sherwood <david.sherwood@arm.com>

From-SVN: r251522

1 files changed, 73 insertions, 64 deletions

diff --git a/gcc/optabs.c b/gcc/optabs.c
index d3ceaba..d30e4c6 100644
--- a/gcc/optabs.c
+++ b/gcc/optabs.c
@@ -4692,6 +4692,7 @@ expand_float (rtx to, rtx from, int unsignedp)
       && is_a <scalar_mode> (GET_MODE (to), &to_mode)
       && is_a <scalar_mode> (GET_MODE (from), &from_mode))
     {
+      opt_scalar_mode fmode_iter;
       rtx_code_label *label = gen_label_rtx ();
       rtx temp;
       REAL_VALUE_TYPE offset;
@@ -4700,12 +4701,15 @@ expand_float (rtx to, rtx from, int unsignedp)
 	 least as wide as the target.  Using FMODE will avoid rounding woes
 	 with unsigned values greater than the signed maximum value.  */
 
-      FOR_EACH_MODE_FROM (fmode, to_mode)
-	if (GET_MODE_PRECISION (from_mode) < GET_MODE_BITSIZE (fmode)
-	    && can_float_p (fmode, from_mode, 0) != CODE_FOR_nothing)
-	  break;
+      FOR_EACH_MODE_FROM (fmode_iter, to_mode)
+	{
+	  scalar_mode fmode = fmode_iter.require ();
+	  if (GET_MODE_PRECISION (from_mode) < GET_MODE_BITSIZE (fmode)
+	      && can_float_p (fmode, from_mode, 0) != CODE_FOR_nothing)
+	    break;
+	}
 
-      if (fmode == VOIDmode)
+      if (!fmode_iter.exists (&fmode))
 	{
 	  /* There is no such mode.  Pretend the target is wide enough.  */
 	  fmode = to_mode;
@@ -4840,6 +4844,7 @@ expand_fix (rtx to, rtx from, int unsignedp)
   enum insn_code icode;
   rtx target = to;
   machine_mode fmode, imode;
+  opt_scalar_mode fmode_iter;
   bool must_trunc = false;
 
   /* We first try to find a pair of modes, one real and one integer, at
@@ -4911,66 +4916,70 @@ expand_fix (rtx to, rtx from, int unsignedp)
   if (unsignedp
       && is_a <scalar_int_mode> (GET_MODE (to), &to_mode)
       && HWI_COMPUTABLE_MODE_P (to_mode))
-    FOR_EACH_MODE_FROM (fmode, GET_MODE (from))
-      if (CODE_FOR_nothing != can_fix_p (to_mode, fmode, 0, &must_trunc)
-	  && (!DECIMAL_FLOAT_MODE_P (fmode)
-	      || GET_MODE_BITSIZE (fmode) > GET_MODE_PRECISION (to_mode)))
-	{
-	  int bitsize;
-	  REAL_VALUE_TYPE offset;
-	  rtx limit;
-	  rtx_code_label *lab1, *lab2;
-	  rtx_insn *insn;
-
-	  bitsize = GET_MODE_PRECISION (to_mode);
-	  real_2expN (&offset, bitsize - 1, fmode);
-	  limit = const_double_from_real_value (offset, fmode);
-	  lab1 = gen_label_rtx ();
-	  lab2 = gen_label_rtx ();
-
-	  if (fmode != GET_MODE (from))
-	    from = convert_to_mode (fmode, from, 0);
-
-	  /* See if we need to do the subtraction.  */
-	  do_pending_stack_adjust ();
-	  emit_cmp_and_jump_insns (from, limit, GE, NULL_RTX, GET_MODE (from),
-				   0, lab1);
-
-	  /* If not, do the signed "fix" and branch around fixup code.  */
-	  expand_fix (to, from, 0);
-	  emit_jump_insn (targetm.gen_jump (lab2));
-	  emit_barrier ();
-
-	  /* Otherwise, subtract 2**(N-1), convert to signed number,
-	     then add 2**(N-1).  Do the addition using XOR since this
-	     will often generate better code.  */
-	  emit_label (lab1);
-	  target = expand_binop (GET_MODE (from), sub_optab, from, limit,
-				 NULL_RTX, 0, OPTAB_LIB_WIDEN);
-	  expand_fix (to, target, 0);
-	  target = expand_binop (to_mode, xor_optab, to,
-				 gen_int_mode
-				 (HOST_WIDE_INT_1 << (bitsize - 1),
-				  to_mode),
-				 to, 1, OPTAB_LIB_WIDEN);
-
-	  if (target != to)
-	    emit_move_insn (to, target);
-
-	  emit_label (lab2);
-
-	  if (optab_handler (mov_optab, to_mode) != CODE_FOR_nothing)
-	    {
-	      /* Make a place for a REG_NOTE and add it.  */
-	      insn = emit_move_insn (to, to);
-	      set_dst_reg_note (insn, REG_EQUAL,
-				gen_rtx_fmt_e (UNSIGNED_FIX, to_mode,
-					       copy_rtx (from)),
-				to);
-	    }
+    FOR_EACH_MODE_FROM (fmode_iter, as_a <scalar_mode> (GET_MODE (from)))
+      {
+	scalar_mode fmode = fmode_iter.require ();
+	if (CODE_FOR_nothing != can_fix_p (to_mode, fmode,
+					   0, &must_trunc)
+	    && (!DECIMAL_FLOAT_MODE_P (fmode)
+		|| (GET_MODE_BITSIZE (fmode) > GET_MODE_PRECISION (to_mode))))
+	  {
+	    int bitsize;
+	    REAL_VALUE_TYPE offset;
+	    rtx limit;
+	    rtx_code_label *lab1, *lab2;
+	    rtx_insn *insn;
+
+	    bitsize = GET_MODE_PRECISION (to_mode);
+	    real_2expN (&offset, bitsize - 1, fmode);
+	    limit = const_double_from_real_value (offset, fmode);
+	    lab1 = gen_label_rtx ();
+	    lab2 = gen_label_rtx ();
 
-	  return;
-	}
+	    if (fmode != GET_MODE (from))
+	      from = convert_to_mode (fmode, from, 0);
+
+	    /* See if we need to do the subtraction.  */
+	    do_pending_stack_adjust ();
+	    emit_cmp_and_jump_insns (from, limit, GE, NULL_RTX,
+				     GET_MODE (from), 0, lab1);
+
+	    /* If not, do the signed "fix" and branch around fixup code.  */
+	    expand_fix (to, from, 0);
+	    emit_jump_insn (targetm.gen_jump (lab2));
+	    emit_barrier ();
+
+	    /* Otherwise, subtract 2**(N-1), convert to signed number,
+	       then add 2**(N-1).  Do the addition using XOR since this
+	       will often generate better code.  */
+	    emit_label (lab1);
+	    target = expand_binop (GET_MODE (from), sub_optab, from, limit,
+				   NULL_RTX, 0, OPTAB_LIB_WIDEN);
+	    expand_fix (to, target, 0);
+	    target = expand_binop (to_mode, xor_optab, to,
+				   gen_int_mode
+				   (HOST_WIDE_INT_1 << (bitsize - 1),
+				    to_mode),
+				   to, 1, OPTAB_LIB_WIDEN);
+
+	    if (target != to)
+	      emit_move_insn (to, target);
+
+	    emit_label (lab2);
+
+	    if (optab_handler (mov_optab, to_mode) != CODE_FOR_nothing)
+	      {
+		/* Make a place for a REG_NOTE and add it.  */
+		insn = emit_move_insn (to, to);
+		set_dst_reg_note (insn, REG_EQUAL,
+				  gen_rtx_fmt_e (UNSIGNED_FIX, to_mode,
+						 copy_rtx (from)),
+				  to);
+	      }
+
+	    return;
+	  }
+      }
 
   /* We can't do it with an insn, so use a library call.  But first ensure
      that the mode of TO is at least as wide as SImode, since those are the