[54/77] Add explicit int checks for alternative optab implementations

expand_unop can expand narrow clz, clrsb, ctz, bswap, parity and
ffs operations using optabs for wider modes.  These expansions
apply only to scalar integer modes (and not for example to vectors),
so the patch adds explicit checks for that.

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

gcc/
	* optabs.c (widen_leading): Change the type of the mode argument
	to scalar_int_mode.  Use opt_scalar_int_mode for the mode iterator.
	(widen_bswap): Likewise.
	(expand_parity): Likewise.
	(expand_ctz): Change the type of the mode argument to scalar_int_mode.
	(expand_ffs): Likewise.
	(epand_unop): Check for scalar integer modes before calling the
	above routines.

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

From-SVN: r251506

gcc/ChangeLog

@@ -2,6 +2,19 @@
 	    Alan Hayward  <alan.hayward@arm.com>
 	    David Sherwood  <david.sherwood@arm.com>
 
+	* optabs.c (widen_leading): Change the type of the mode argument
+	to scalar_int_mode.  Use opt_scalar_int_mode for the mode iterator.
+	(widen_bswap): Likewise.
+	(expand_parity): Likewise.
+	(expand_ctz): Change the type of the mode argument to scalar_int_mode.
+	(expand_ffs): Likewise.
+	(epand_unop): Check for scalar integer modes before calling the
+	above routines.
+
+2017-08-30  Richard Sandiford  <richard.sandiford@linaro.org>
+	    Alan Hayward  <alan.hayward@arm.com>
+	    David Sherwood  <david.sherwood@arm.com>
+
 	* expr.c (const_scalar_mask_from_tree): Add a mode argument.
 	Expand commentary.
 	(expand_expr_real_1): Update call accordingly.

gcc/optabs.c

@@ -2129,14 +2129,12 @@ expand_simple_unop (machine_mode mode, enum rtx_code code, rtx op0,
    A similar operation can be used for clrsb.  UNOPTAB says which operation
    we are trying to expand.  */
 static rtx
-widen_leading (machine_mode mode, rtx op0, rtx target, optab unoptab)
+widen_leading (scalar_int_mode mode, rtx op0, rtx target, optab unoptab)
 {
-  enum mode_class mclass = GET_MODE_CLASS (mode);
-  if (CLASS_HAS_WIDER_MODES_P (mclass))
-    {
-      machine_mode wider_mode;
-      FOR_EACH_WIDER_MODE (wider_mode, mode)
+  opt_scalar_int_mode wider_mode_iter;
+  FOR_EACH_WIDER_MODE (wider_mode_iter, mode)
     {
+      scalar_int_mode wider_mode = wider_mode_iter.require ();
       if (optab_handler (unoptab, wider_mode) != CODE_FOR_nothing)
 	{
 	  rtx xop0, temp;
@@ -2163,7 +2161,6 @@ widen_leading (machine_mode mode, rtx op0, rtx target, optab unoptab)
 	  return temp;
 	}
     }
-    }
   return 0;
 }
 
@@ -2295,22 +2292,21 @@ expand_doubleword_parity (machine_mode mode, rtx op0, rtx target)
    as
 	(lshiftrt:wide (bswap:wide x) ((width wide) - (width narrow))).  */
 static rtx
-widen_bswap (machine_mode mode, rtx op0, rtx target)
+widen_bswap (scalar_int_mode mode, rtx op0, rtx target)
 {
-  enum mode_class mclass = GET_MODE_CLASS (mode);
-  machine_mode wider_mode;
   rtx x;
   rtx_insn *last;
+  opt_scalar_int_mode wider_mode_iter;
 
-  if (!CLASS_HAS_WIDER_MODES_P (mclass))
-    return NULL_RTX;
+  FOR_EACH_WIDER_MODE (wider_mode_iter, mode)
+    if (optab_handler (bswap_optab, wider_mode_iter.require ())
+	!= CODE_FOR_nothing)
+      break;
 
-  FOR_EACH_WIDER_MODE (wider_mode, mode)
-    if (optab_handler (bswap_optab, wider_mode) != CODE_FOR_nothing)
-      goto found;
+  if (!wider_mode_iter.exists ())
     return NULL_RTX;
 
- found:
+  scalar_int_mode wider_mode = wider_mode_iter.require ();
   last = get_last_insn ();
 
   x = widen_operand (op0, wider_mode, mode, true, true);
@@ -2361,14 +2357,13 @@ expand_doubleword_bswap (machine_mode mode, rtx op, rtx target)
 /* Try calculating (parity x) as (and (popcount x) 1), where
    popcount can also be done in a wider mode.  */
 static rtx
-expand_parity (machine_mode mode, rtx op0, rtx target)
+expand_parity (scalar_int_mode mode, rtx op0, rtx target)
 {
   enum mode_class mclass = GET_MODE_CLASS (mode);
-  if (CLASS_HAS_WIDER_MODES_P (mclass))
-    {
-      machine_mode wider_mode;
-      FOR_EACH_MODE_FROM (wider_mode, mode)
+  opt_scalar_int_mode wider_mode_iter;
+  FOR_EACH_MODE_FROM (wider_mode_iter, mode)
     {
+      scalar_int_mode wider_mode = wider_mode_iter.require ();
       if (optab_handler (popcount_optab, wider_mode) != CODE_FOR_nothing)
 	{
 	  rtx xop0, temp;
@@ -2398,7 +2393,6 @@ expand_parity (machine_mode mode, rtx op0, rtx target)
 	    delete_insns_since (last);
 	}
     }
-    }
   return 0;
 }
 
@@ -2415,7 +2409,7 @@ expand_parity (machine_mode mode, rtx op0, rtx target)
    less convenient for expand_ffs anyway.  */
 
 static rtx
-expand_ctz (machine_mode mode, rtx op0, rtx target)
+expand_ctz (scalar_int_mode mode, rtx op0, rtx target)
 {
   rtx_insn *seq;
   rtx temp;
@@ -2458,7 +2452,7 @@ expand_ctz (machine_mode mode, rtx op0, rtx target)
    may have an undefined value in that case.  If they do not give us a
    convenient value, we have to generate a test and branch.  */
 static rtx
-expand_ffs (machine_mode mode, rtx op0, rtx target)
+expand_ffs (scalar_int_mode mode, rtx op0, rtx target)
 {
   HOST_WIDE_INT val = 0;
   bool defined_at_zero = false;
@@ -2715,26 +2709,32 @@ expand_unop (machine_mode mode, optab unoptab, rtx op0, rtx target,
   /* Widening (or narrowing) clz needs special treatment.  */
   if (unoptab == clz_optab)
     {
-      temp = widen_leading (mode, op0, target, unoptab);
+      if (is_a <scalar_int_mode> (mode, &int_mode))
+	{
+	  temp = widen_leading (int_mode, op0, target, unoptab);
 	  if (temp)
 	    return temp;
 
-      if (GET_MODE_SIZE (mode) == 2 * UNITS_PER_WORD
+	  if (GET_MODE_SIZE (int_mode) == 2 * UNITS_PER_WORD
 	      && optab_handler (unoptab, word_mode) != CODE_FOR_nothing)
 	    {
-	  temp = expand_doubleword_clz (mode, op0, target);
+	      temp = expand_doubleword_clz (int_mode, op0, target);
 	      if (temp)
 		return temp;
 	    }
+	}
 
       goto try_libcall;
     }
 
   if (unoptab == clrsb_optab)
     {
-      temp = widen_leading (mode, op0, target, unoptab);
+      if (is_a <scalar_int_mode> (mode, &int_mode))
+	{
+	  temp = widen_leading (int_mode, op0, target, unoptab);
 	  if (temp)
 	    return temp;
+	}
       goto try_libcall;
     }
 
@@ -2806,17 +2806,20 @@ expand_unop (machine_mode mode, optab unoptab, rtx op0, rtx target,
 	  delete_insns_since (last);
 	}
 
-      temp = widen_bswap (mode, op0, target);
+      if (is_a <scalar_int_mode> (mode, &int_mode))
+	{
+	  temp = widen_bswap (int_mode, op0, target);
 	  if (temp)
 	    return temp;
 
-      if (GET_MODE_SIZE (mode) == 2 * UNITS_PER_WORD
+	  if (GET_MODE_SIZE (int_mode) == 2 * UNITS_PER_WORD
 	      && optab_handler (unoptab, word_mode) != CODE_FOR_nothing)
 	    {
 	      temp = expand_doubleword_bswap (mode, op0, target);
 	      if (temp)
 		return temp;
 	    }
+	}
 
       goto try_libcall;
     }
@@ -2916,25 +2919,25 @@ expand_unop (machine_mode mode, optab unoptab, rtx op0, rtx target,
     }
 
   /* Try calculating parity (x) as popcount (x) % 2.  */
-  if (unoptab == parity_optab)
+  if (unoptab == parity_optab && is_a <scalar_int_mode> (mode, &int_mode))
     {
-      temp = expand_parity (mode, op0, target);
+      temp = expand_parity (int_mode, op0, target);
       if (temp)
 	return temp;
     }
 
   /* Try implementing ffs (x) in terms of clz (x).  */
-  if (unoptab == ffs_optab)
+  if (unoptab == ffs_optab && is_a <scalar_int_mode> (mode, &int_mode))
     {
-      temp = expand_ffs (mode, op0, target);
+      temp = expand_ffs (int_mode, op0, target);
       if (temp)
 	return temp;
     }
 
   /* Try implementing ctz (x) in terms of clz (x).  */
-  if (unoptab == ctz_optab)
+  if (unoptab == ctz_optab && is_a <scalar_int_mode> (mode, &int_mode))
     {
-      temp = expand_ctz (mode, op0, target);
+      temp = expand_ctz (int_mode, op0, target);
       if (temp)
 	return temp;
     }