re PR middle-end/77925 (Add __builtin_issubnormal)

2017-06-08  Tamar Christina  <tamar.christina@arm.com>

	PR middle-end/77925
	PR middle-end/77926
	PR middle-end/66462

	* gcc/builtins.c (fold_builtin_fpclassify): Remove.
	(fold_builtin_interclass_mathfn): Remove.
	(expand_builtin): Add builtins to lowering list.
	(fold_builtin_n): Remove fold_builtin_varargs.
	(fold_builtin_varargs): Remove.
	* gcc/builtins.def (BUILT_IN_ISZERO, BUILT_IN_ISSUBNORMAL): New.
	* gcc/real.h (get_min_float): New.
	(real_format): Add is_ieee_compatible field.
	* gcc/real.c (get_min_float): New.
	(ieee_single_format): Set is_ieee_compatible flag.
	* gcc/gimple-low.c (lower_stm): Define BUILT_IN_FPCLASSIFY,
	CASE_FLT_FN (BUILT_IN_ISINF), BUILT_IN_ISINFD32, BUILT_IN_ISINFD64,
	BUILT_IN_ISINFD128, BUILT_IN_ISNAND32, BUILT_IN_ISNAND64,
	BUILT_IN_ISNAND128, BUILT_IN_ISNAN, BUILT_IN_ISNORMAL, BUILT_IN_ISZERO,
	BUILT_IN_ISSUBNORMAL, CASE_FLT_FN (BUILT_IN_FINITE), BUILT_IN_FINITED32
	BUILT_IN_FINITED64, BUILT_IN_FINITED128, BUILT_IN_ISFINITE.
	(lower_builtin_fpclassify, is_nan, is_normal, is_infinity): New.
	(is_zero, is_subnormal, is_finite, use_ieee_int_mode): Likewise.
	(lower_builtin_isnan, lower_builtin_isinfinite): Likewise.
	(lower_builtin_isnormal, lower_builtin_iszero): Likewise.
	(lower_builtin_issubnormal, lower_builtin_isfinite): Likewise.
	(emit_tree_cond, get_num_as_int, emit_tree_and_return_var): New.
	(mips_single_format): Likewise.
	(motorola_single_format): Likewise.
	(spu_single_format): Likewise.
	(ieee_double_format): Likewise.
	(mips_double_format): Likewise.
	(motorola_double_format): Likewise.
	(ieee_extended_motorola_format): Likewise.
	(ieee_extended_intel_128_format): Likewise.
	(ieee_extended_intel_96_round_53_format): Likewise.
	(ibm_extended_format): Likewise.
	(mips_extended_format): Likewise.
	(ieee_quad_format): Likewise.
	(mips_quad_format): Likewise.
	(vax_f_format): Likewise.
	(vax_d_format): Likewise.
	(vax_g_format): Likewise.
	(decimal_single_format): Likewise.
	(decimal_quad_format): Likewise.
	(iee_half_format): Likewise.
	(mips_single_format): Likewise.
	(arm_half_format): Likewise.
	(real_internal_format): Likewise.
	* gcc/doc/extend.texi: Add documentation for built-ins.
	* gcc/c/c-typeck.c (convert_arguments): Add BUILT_IN_ISZERO
	and BUILT_IN_ISSUBNORMAL.

gcc/testsuite/
2017-06-08  Tamar Christina  <tamar.christina@arm.com>

	* gcc.target/aarch64/builtin-fpclassify.c: New codegen test.
	* gcc.dg/fold-notunord.c: Removed.
	* gcc.dg/torture/floatn-tg-4.h: Add tests for iszero and issubnormal.
	* gcc.dg/torture/float128-tg-4.c: Likewise.
	* gcc.dg/torture/float128x-tg-4: Likewise.
	* gcc.dg/torture/float16-tg-4.c: Likewise.
	* gcc.dg/torture/float32-tg-4.c: Likewise.
	* gcc.dg/torture/float32x-tg-4.c: Likewise.
	* gcc.dg/torture/float64-tg-4.c: Likewise.
	* gcc.dg/torture/float64x-tg-4.c: Likewise.
	* gcc.dg/pr28796-1.c: Add -O2.
	* gcc.dg/builtins-43.c: Check lower instead of gimple.
	* gcc.dg/tg-tests.h: Add iszero and issubnormal.
	* gcc.dg/pr77925.c: Add to test safe cases.

From-SVN: r249005

1 files changed, 903 insertions, 7 deletions

diff --git a/gcc/gimple-low.c b/gcc/gimple-low.c
index 619b9d7..1cc4a4d 100644
--- a/gcc/gimple-low.c
+++ b/gcc/gimple-low.c
@@ -30,6 +30,9 @@ along with GCC; see the file COPYING3.  If not see
 #include "calls.h"
 #include "gimple-iterator.h"
 #include "gimple-low.h"
+#include "stor-layout.h"
+#include "target.h"
+#include "gimplify.h"
 
 /* The differences between High GIMPLE and Low GIMPLE are the
    following:
@@ -72,6 +75,13 @@ static void lower_gimple_bind (gimple_stmt_iterator *, struct lower_data *);
 static void lower_try_catch (gimple_stmt_iterator *, struct lower_data *);
 static void lower_gimple_return (gimple_stmt_iterator *, struct lower_data *);
 static void lower_builtin_setjmp (gimple_stmt_iterator *);
+static void lower_builtin_fpclassify (gimple_stmt_iterator *);
+static void lower_builtin_isnan (gimple_stmt_iterator *);
+static void lower_builtin_isinfinite (gimple_stmt_iterator *);
+static void lower_builtin_isnormal (gimple_stmt_iterator *);
+static void lower_builtin_iszero (gimple_stmt_iterator *);
+static void lower_builtin_issubnormal (gimple_stmt_iterator *);
+static void lower_builtin_isfinite (gimple_stmt_iterator *);
 static void lower_builtin_posix_memalign (gimple_stmt_iterator *);
 
 
@@ -330,18 +340,69 @@ lower_stmt (gimple_stmt_iterator *gsi, struct lower_data *data)
 	if (decl
 	    && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL)
 	  {
-	    if (DECL_FUNCTION_CODE (decl) == BUILT_IN_SETJMP)
+	    switch (DECL_FUNCTION_CODE (decl))
 	      {
+	      case BUILT_IN_SETJMP:
 		lower_builtin_setjmp (gsi);
 		data->cannot_fallthru = false;
 		return;
-	      }
-	    else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_POSIX_MEMALIGN
-		     && flag_tree_bit_ccp
-		     && gimple_builtin_call_types_compatible_p (stmt, decl))
-	      {
-		lower_builtin_posix_memalign (gsi);
+
+	      case BUILT_IN_POSIX_MEMALIGN:
+		if (flag_tree_bit_ccp
+		    && gimple_builtin_call_types_compatible_p (stmt, decl))
+		  {
+			lower_builtin_posix_memalign (gsi);
+			return;
+		  }
+		break;
+
+	      case BUILT_IN_FPCLASSIFY:
+		lower_builtin_fpclassify (gsi);
+		data->cannot_fallthru = false;
+		return;
+
+	      CASE_FLT_FN (BUILT_IN_ISINF):
+	      case BUILT_IN_ISINFD32:
+	      case BUILT_IN_ISINFD64:
+	      case BUILT_IN_ISINFD128:
+		lower_builtin_isinfinite (gsi);
+		data->cannot_fallthru = false;
+		return;
+
+	      case BUILT_IN_ISNAND32:
+	      case BUILT_IN_ISNAND64:
+	      case BUILT_IN_ISNAND128:
+	      CASE_FLT_FN (BUILT_IN_ISNAN):
+		lower_builtin_isnan (gsi);
+		data->cannot_fallthru = false;
+		return;
+
+	      case BUILT_IN_ISNORMAL:
+		lower_builtin_isnormal (gsi);
+		data->cannot_fallthru = false;
+		return;
+
+	      case BUILT_IN_ISZERO:
+		lower_builtin_iszero (gsi);
+		data->cannot_fallthru = false;
+		return;
+
+	      case BUILT_IN_ISSUBNORMAL:
+		lower_builtin_issubnormal (gsi);
+		data->cannot_fallthru = false;
+		return;
+
+	      CASE_FLT_FN (BUILT_IN_FINITE):
+	      case BUILT_IN_FINITED32:
+	      case BUILT_IN_FINITED64:
+	      case BUILT_IN_FINITED128:
+	      case BUILT_IN_ISFINITE:
+		lower_builtin_isfinite (gsi);
+		data->cannot_fallthru = false;
 		return;
+
+	      default:
+		break;
 	      }
 	  }
 
@@ -822,6 +883,841 @@ lower_builtin_setjmp (gimple_stmt_iterator *gsi)
   gsi_remove (gsi, false);
 }
 
+/* This function will if ARG is not already a variable or SSA_NAME,
+   create a new temporary TMP and bind ARG to TMP.  This new binding is then
+   emitted into SEQ and TMP is returned.  */
+static tree
+emit_tree_and_return_var (gimple_seq *seq, tree arg)
+{
+  if (TREE_CODE (arg) == SSA_NAME || VAR_P (arg))
+    return arg;
+
+  tree tmp = create_tmp_reg (TREE_TYPE (arg));
+  gassign *stm = gimple_build_assign (tmp, arg);
+  gimple_seq_add_stmt (seq, stm);
+  return tmp;
+}
+
+/* This function builds an if statement that ends up using explicit branches
+   instead of becoming a ternary conditional select.  This function assumes you
+   will fall through to the next statements after the condition for the false
+   branch.  The code emitted looks like:
+
+   if (COND)
+     RESULT_VARIABLE = TRUE_BRANCH
+     GOTO EXIT_LABEL
+   else
+     ...
+
+   SEQ is the gimple sequence/buffer to emit any new bindings to.
+   RESULT_VARIABLE is the value to set if COND.
+   EXIT_LABEL is the label to jump to in case COND.
+   COND is condition to use in the conditional statement of the if.
+   TRUE_BRANCH is the value to set RESULT_VARIABLE to if COND.  */
+static void
+emit_tree_cond (gimple_seq *seq, tree result_variable, tree exit_label,
+		tree cond, tree true_branch)
+{
+  /* Create labels for fall through.  */
+  tree true_label = create_artificial_label (UNKNOWN_LOCATION);
+  tree false_label = create_artificial_label (UNKNOWN_LOCATION);
+  gcond *stmt = gimple_build_cond_from_tree (cond, true_label, false_label);
+  gimple_seq_add_stmt (seq, stmt);
+
+  /* Build the true case.  */
+  gimple_seq_add_stmt (seq, gimple_build_label (true_label));
+  tree value = TREE_CONSTANT (true_branch)
+	     ? true_branch
+	     : emit_tree_and_return_var (seq, true_branch);
+  gimple_seq_add_stmt (seq, gimple_build_assign (result_variable, value));
+  gimple_seq_add_stmt (seq, gimple_build_goto (exit_label));
+
+  /* Build the false case.  */
+  gimple_seq_add_stmt (seq, gimple_build_label (false_label));
+}
+
+/* This function returns a variable containing an reinterpreted ARG as an
+   integer.
+
+   SEQ is the gimple sequence/buffer to write any new bindings to.
+   ARG is the floating point number to reinterpret as an integer.
+   LOC is the location to use when doing folding operations.  */
+static tree
+get_num_as_int (gimple_seq *seq, tree arg, location_t loc)
+{
+  tree type = TREE_TYPE (arg);
+
+  const HOST_WIDE_INT type_width = TYPE_PRECISION (type);
+
+  /* Re-interpret the float as an unsigned integer type
+     with equal precision.  */
+  tree int_arg_type = build_nonstandard_integer_type (type_width, true);
+  tree conv_arg = fold_build1_loc (loc, VIEW_CONVERT_EXPR, int_arg_type, arg);
+  return emit_tree_and_return_var (seq, conv_arg);
+}
+
+/* Check if ARG which is the floating point number being classified is close
+   enough to IEEE 754 format to be able to go in the early exit code.  */
+static bool
+use_ieee_int_mode (tree arg)
+{
+  tree type = TREE_TYPE (arg);
+  machine_mode mode = TYPE_MODE (type);
+
+  const real_format *format = REAL_MODE_FORMAT (mode);
+  machine_mode imode = int_mode_for_mode (mode);
+  bool is_ibm_extended = MODE_COMPOSITE_P (mode);
+
+  return (format->is_binary_ieee_compatible
+	  && FLOAT_WORDS_BIG_ENDIAN == WORDS_BIG_ENDIAN
+	  /* Check if there's a usable integer mode.  */
+	  && imode != BLKmode
+	  && targetm.scalar_mode_supported_p (imode)
+	  && !is_ibm_extended);
+}
+
+/* Perform some IBM extended format fixups on ARG for use by FP functions.
+   This is done by ignoring the lower 64 bits of the number.
+
+   MODE is the machine mode of ARG.
+   TYPE is the type of ARG.
+   LOC is the location to be used in fold functions.  Usually is the location
+   of the definition of ARG.  */
+static bool
+perform_ibm_extended_fixups (tree *arg, machine_mode *mode,
+			     tree *type, location_t loc)
+{
+  bool is_ibm_extended = MODE_COMPOSITE_P (*mode);
+  if (is_ibm_extended)
+    {
+      /* NaN and Inf are encoded in the high-order double value
+	 only.  The low-order value is not significant.  */
+      *type = double_type_node;
+      *mode = DFmode;
+      *arg = fold_build1_loc (loc, NOP_EXPR, *type, *arg);
+    }
+
+  return is_ibm_extended;
+}
+
+/* Generates code to check if ARG is a normal number.  For the FP case we check
+   MIN_VALUE(ARG) <= ABS(ARG) > INF and for the INT value we check the exp and
+   mantissa bits.  Returns a variable containing a boolean which has the result
+   of the check.
+
+   SEQ is the buffer to use to emit the gimple instructions into.
+   LOC is the location to use during fold calls.  */
+static tree
+is_normal (gimple_seq *seq, tree arg, location_t loc)
+{
+  tree type = TREE_TYPE (arg);
+
+  machine_mode mode = TYPE_MODE (type);
+  const real_format *format = REAL_MODE_FORMAT (mode);
+  const tree bool_type = boolean_type_node;
+
+
+  /* If not using optimized route then exit early.  */
+  if (!use_ieee_int_mode (arg))
+    {
+      tree orig_arg = arg;
+      machine_mode orig_mode = mode;
+      if (TREE_CODE (arg) != SSA_NAME
+	  && (TREE_ADDRESSABLE (arg) != 0
+	    || (TREE_CODE (arg) != PARM_DECL
+	        && (!VAR_P (arg) || TREE_STATIC (arg)))))
+	orig_arg = save_expr (arg);
+
+      /* Perform IBM extended format fixups if required.  */
+      bool is_ibm_extended = perform_ibm_extended_fixups (&arg, &mode,
+							  &type, loc);
+
+      REAL_VALUE_TYPE rinf, rmin;
+      tree arg_p = fold_build1_loc (loc, ABS_EXPR, type, arg);
+
+      tree const islt_fn = builtin_decl_explicit (BUILT_IN_ISLESS);
+      tree const isgt_fn = builtin_decl_explicit (BUILT_IN_ISGREATER);
+      tree const isge_fn = builtin_decl_explicit (BUILT_IN_ISGREATEREQUAL);
+
+      char buf[128];
+      real_inf (&rinf);
+      get_min_float (REAL_MODE_FORMAT (orig_mode), buf, sizeof (buf));
+      real_from_string (&rmin, buf);
+
+      tree inf_exp = build_call_expr (islt_fn, 2, arg_p,
+				      build_real (type, rinf));
+      tree min_exp = build_real (type, rmin);
+      if (is_ibm_extended)
+	{
+	  /* Testing the high end of the range is done just using
+	     the high double, using the same test as isfinite().
+	     For the subnormal end of the range we first test the
+	     high double, then if its magnitude is equal to the
+	     limit of 0x1p-969, we test whether the low double is
+	     non-zero and opposite sign to the high double.  */
+	  tree gt_min = build_call_expr (isgt_fn, 2, arg_p, min_exp);
+	  tree eq_min = fold_build2 (EQ_EXPR, integer_type_node,
+				     arg_p, min_exp);
+	  tree as_complex = build1 (VIEW_CONVERT_EXPR,
+				    complex_double_type_node, orig_arg);
+	  tree hi_dbl = build1 (REALPART_EXPR, type, as_complex);
+	  tree lo_dbl = build1 (IMAGPART_EXPR, type, as_complex);
+	  tree zero = build_real (type, dconst0);
+	  tree hilt = build_call_expr (islt_fn, 2, hi_dbl, zero);
+	  tree lolt = build_call_expr (islt_fn, 2, lo_dbl, zero);
+	  tree logt = build_call_expr (isgt_fn, 2, lo_dbl, zero);
+	  tree ok_lo = fold_build1 (TRUTH_NOT_EXPR, integer_type_node,
+				    fold_build3 (COND_EXPR,
+						 integer_type_node,
+						 hilt, logt, lolt));
+	  eq_min = fold_build2 (TRUTH_ANDIF_EXPR, integer_type_node,
+				eq_min, ok_lo);
+	  min_exp = fold_build2 (TRUTH_ORIF_EXPR, integer_type_node,
+				 gt_min, eq_min);
+	}
+	else
+	{
+	  min_exp = build_call_expr (isge_fn, 2, arg_p, min_exp);
+	}
+
+      push_gimplify_context ();
+      gimplify_expr (&min_exp, seq, NULL, is_gimple_val, fb_either);
+      gimplify_expr (&inf_exp, seq, NULL, is_gimple_val, fb_either);
+
+      tree res
+	= fold_build2_loc (loc, BIT_AND_EXPR, bool_type,
+			   emit_tree_and_return_var (seq,
+						     gimple_boolify (min_exp)),
+			   emit_tree_and_return_var (seq,
+						     gimple_boolify (inf_exp)));
+      pop_gimplify_context (NULL);
+
+      return emit_tree_and_return_var (seq, res);
+    }
+
+  const tree int_type = unsigned_type_node;
+  const int exp_bits  = (GET_MODE_SIZE (mode) * BITS_PER_UNIT) - format->p;
+  const int exp_mask  = (1 << exp_bits) - 1;
+
+  /* Get the number reinterpreted as an integer.  */
+  tree int_arg = get_num_as_int (seq, arg, loc);
+
+  /* Extract exp bits from the float, where we expect the exponent to be.
+     We create a new type because BIT_FIELD_REF does not allow you to
+     extract less bits than the precision of the storage variable.  */
+  tree exp_tmp
+    = fold_build3_loc (loc, BIT_FIELD_REF,
+		       build_nonstandard_integer_type (exp_bits, true),
+		       int_arg,
+		       build_int_cstu (int_type, exp_bits),
+		       build_int_cstu (int_type, format->p - 1));
+  tree exp_bitfield = emit_tree_and_return_var (seq, exp_tmp);
+
+  /* Re-interpret the extracted exponent bits as a 32 bit int.
+     This allows us to continue doing operations as int_type.  */
+  tree exp
+    = emit_tree_and_return_var (seq, fold_build1_loc (loc, NOP_EXPR, int_type,
+						      exp_bitfield));
+
+  /* exp_mask & ~1.  */
+  tree mask_check
+     = fold_build2_loc (loc, BIT_AND_EXPR, int_type,
+			build_int_cstu (int_type, exp_mask),
+			fold_build1_loc (loc, BIT_NOT_EXPR, int_type,
+					 build_int_cstu (int_type, 1)));
+
+  /* (exp + 1) & mask_check.
+     Check to see if exp is not all 0 or all 1.  */
+  tree exp_check
+    = fold_build2_loc (loc, BIT_AND_EXPR, int_type,
+		       emit_tree_and_return_var (seq,
+				fold_build2_loc (loc, PLUS_EXPR, int_type, exp,
+						 build_int_cstu (int_type, 1))),
+		       mask_check);
+
+  tree res = fold_build2_loc (loc, NE_EXPR, boolean_type_node,
+			      build_int_cstu (int_type, 0),
+			      emit_tree_and_return_var (seq, exp_check));
+
+  return emit_tree_and_return_var (seq, res);
+}
+
+/* Generates code to check if ARG is a zero. For both the FP and INT case we
+   check if ARG == 0 (modulo sign bit).  Returns a variable containing a boolean
+   which has the result of the check.
+
+   SEQ is the buffer to use to emit the gimple instructions into.
+   LOC is the location to use during fold calls.  */
+static tree
+is_zero (gimple_seq *seq, tree arg, location_t loc)
+{
+  tree type = TREE_TYPE (arg);
+
+  /* If not using optimized route then exit early.  */
+  if (!use_ieee_int_mode (arg))
+    {
+      machine_mode mode = TYPE_MODE (type);
+      /* Perform IBM extended format fixups if required.  */
+      perform_ibm_extended_fixups (&arg, &mode, &type, loc);
+
+      tree res = fold_build2_loc (loc, EQ_EXPR, boolean_type_node, arg,
+				  build_real (type, dconst0));
+      return emit_tree_and_return_var (seq, res);
+    }
+
+  const HOST_WIDE_INT type_width = TYPE_PRECISION (type);
+
+  tree int_arg_type = build_nonstandard_integer_type (type_width, true);
+
+  /* Get the number reinterpreted as an integer.
+     Shift left to remove the sign.  */
+  tree int_arg
+    = fold_build2_loc (loc, LSHIFT_EXPR, int_arg_type,
+		       get_num_as_int (seq, arg, loc),
+		       build_int_cstu (int_arg_type, 1));
+
+  /* num << 1 == 0.
+     This checks to see if the number is zero.  */
+  tree zero_check
+    = fold_build2_loc (loc, EQ_EXPR, boolean_type_node,
+		       build_int_cstu (int_arg_type, 0),
+		       emit_tree_and_return_var (seq, int_arg));
+
+  return emit_tree_and_return_var (seq, zero_check);
+}
+
+/* Generates code to check if ARG is a subnormal number.  In the FP case we test
+   fabs (ARG) != 0 && fabs (ARG) < MIN_VALUE (ARG) and in the INT case we check
+   the exp and mantissa bits on ARG. Returns a variable containing a boolean
+   which has the result of the check.
+
+   SEQ is the buffer to use to emit the gimple instructions into.
+   LOC is the location to use during fold calls.  */
+static tree
+is_subnormal (gimple_seq *seq, tree arg, location_t loc)
+{
+  const tree bool_type = boolean_type_node;
+
+  tree type = TREE_TYPE (arg);
+
+  machine_mode mode = TYPE_MODE (type);
+  const real_format *format = REAL_MODE_FORMAT (mode);
+  const HOST_WIDE_INT type_width = TYPE_PRECISION (type);
+
+  tree int_arg_type = build_nonstandard_integer_type (type_width, true);
+
+  /* If not using optimized route then exit early.  */
+  if (!use_ieee_int_mode (arg))
+    {
+      tree const islt_fn = builtin_decl_explicit (BUILT_IN_ISLESS);
+      tree const isgt_fn = builtin_decl_explicit (BUILT_IN_ISGREATER);
+
+      tree arg_p
+	= emit_tree_and_return_var (seq, fold_build1_loc (loc, ABS_EXPR, type,
+							  arg));
+      REAL_VALUE_TYPE r;
+      char buf[128];
+      get_min_float (REAL_MODE_FORMAT (mode), buf, sizeof (buf));
+      real_from_string (&r, buf);
+      tree subnorm = build_call_expr (islt_fn, 2, arg_p, build_real (type, r));
+
+      tree zero = build_call_expr (isgt_fn, 2, arg_p,
+				   build_real (type, dconst0));
+
+      push_gimplify_context ();
+      gimplify_expr (&subnorm, seq, NULL, is_gimple_val, fb_either);
+      gimplify_expr (&zero, seq, NULL, is_gimple_val, fb_either);
+
+      tree res
+	= fold_build2_loc (loc, BIT_AND_EXPR, bool_type,
+			   emit_tree_and_return_var (seq,
+						     gimple_boolify (subnorm)),
+			   emit_tree_and_return_var (seq,
+						     gimple_boolify (zero)));
+      pop_gimplify_context (NULL);
+
+      return emit_tree_and_return_var (seq, res);
+  }
+
+  /* Get the number reinterpreted as an integer.
+     Shift left to remove the sign.  */
+  tree int_arg
+    = fold_build2_loc (loc, LSHIFT_EXPR, int_arg_type,
+		       get_num_as_int (seq, arg, loc),
+		       build_int_cstu (int_arg_type, 1));
+
+  /* Check for a zero exponent and non-zero mantissa.
+     This can be done with two comparisons by first apply a
+     removing the sign bit and checking if the value is larger
+     than the mantissa mask.  */
+
+  /* This creates a mask to be used to check the mantissa value in the shifted
+     integer representation of the fpnum.  */
+  tree significant_bit = build_int_cstu (int_arg_type, format->p - 1);
+  tree mantissa_mask
+    = fold_build2_loc (loc, MINUS_EXPR, int_arg_type,
+		       fold_build2_loc (loc, LSHIFT_EXPR, int_arg_type,
+					build_int_cstu (int_arg_type, 2),
+					significant_bit),
+		       build_int_cstu (int_arg_type, 1));
+
+  /* Check if exponent is zero and mantissa is not.  */
+  tree subnorm_cond_tmp
+    = fold_build2_loc (loc, LE_EXPR, bool_type,
+		       emit_tree_and_return_var (seq, int_arg),
+		       mantissa_mask);
+
+  tree subnorm_cond = emit_tree_and_return_var (seq, subnorm_cond_tmp);
+
+  tree zero_cond
+    = fold_build2_loc (loc, GT_EXPR, boolean_type_node,
+		       emit_tree_and_return_var (seq, int_arg),
+		       build_int_cstu (int_arg_type, 0));
+
+  tree subnorm_check
+    = fold_build2_loc (loc, BIT_AND_EXPR, boolean_type_node,
+		       emit_tree_and_return_var (seq, subnorm_cond),
+		       emit_tree_and_return_var (seq, zero_cond));
+
+  return emit_tree_and_return_var (seq, subnorm_check);
+}
+
+/* Generates code to check if ARG is an infinity.  In the FP case we test
+   FABS(ARG) == INF and in the INT case we check the bits on the exp and
+   mantissa.  Returns a variable containing a boolean which has the result
+   of the check.
+
+   SEQ is the buffer to use to emit the gimple instructions into.
+   LOC is the location to use during fold calls.  */
+static tree
+is_infinity (gimple_seq *seq, tree arg, location_t loc)
+{
+  tree type = TREE_TYPE (arg);
+
+  machine_mode mode = TYPE_MODE (type);
+  const tree bool_type = boolean_type_node;
+
+  if (!HONOR_INFINITIES (mode))
+    {
+      return build_int_cst (bool_type, false);
+    }
+
+  /* If not using optimized route then exit early.  */
+  if (!use_ieee_int_mode (arg))
+    {
+      /* Perform IBM extended format fixups if required.  */
+      perform_ibm_extended_fixups (&arg, &mode, &type, loc);
+
+      tree arg_p
+	= emit_tree_and_return_var (seq, fold_build1_loc (loc, ABS_EXPR, type,
+							arg));
+      REAL_VALUE_TYPE r;
+      real_inf (&r);
+      tree res = fold_build2_loc (loc, EQ_EXPR, bool_type, arg_p,
+				  build_real (type, r));
+
+      return emit_tree_and_return_var (seq, res);
+    }
+
+  const real_format *format = REAL_MODE_FORMAT (mode);
+  const HOST_WIDE_INT type_width = TYPE_PRECISION (type);
+
+  tree int_arg_type = build_nonstandard_integer_type (type_width, true);
+
+  /* This creates a mask to be used to check the exp value in the shifted
+     integer representation of the fpnum.  */
+  const int exp_bits  = (GET_MODE_SIZE (mode) * BITS_PER_UNIT) - format->p;
+  gcc_assert (format->p > 0);
+
+  tree significant_bit = build_int_cstu (int_arg_type, format->p);
+  tree exp_mask
+    = fold_build2_loc (loc, MINUS_EXPR, int_arg_type,
+		       fold_build2_loc (loc, LSHIFT_EXPR, int_arg_type,
+					build_int_cstu (int_arg_type, 2),
+					build_int_cstu (int_arg_type,
+							exp_bits - 1)),
+		       build_int_cstu (int_arg_type, 1));
+
+  /* Get the number reinterpreted as an integer.
+     Shift left to remove the sign.  */
+  tree int_arg
+    = fold_build2_loc (loc, LSHIFT_EXPR, int_arg_type,
+		       get_num_as_int (seq, arg, loc),
+		       build_int_cstu (int_arg_type, 1));
+
+  /* This mask checks to see if the exp has all bits set and mantissa no
+     bits set.  */
+  tree inf_mask
+    = fold_build2_loc (loc, LSHIFT_EXPR, int_arg_type,
+		       exp_mask, significant_bit);
+
+  /* Check if exponent has all bits set and mantissa is 0.  */
+  tree inf_check
+    = emit_tree_and_return_var(seq,
+	fold_build2_loc (loc, EQ_EXPR, bool_type,
+			 emit_tree_and_return_var(seq, int_arg),
+			 inf_mask));
+
+  return emit_tree_and_return_var (seq, inf_check);
+}
+
+/* Generates code to check if ARG is a finite number.  In the FP case we check
+   if FABS(ARG) <= MAX_VALUE(ARG) and in the INT case we check the exp and
+   mantissa bits.  Returns a variable containing a boolean which has the result
+   of the check.
+
+   SEQ is the buffer to use to emit the gimple instructions into.
+   LOC is the location to use during fold calls.  */
+static tree
+is_finite (gimple_seq *seq, tree arg, location_t loc)
+{
+  tree type = TREE_TYPE (arg);
+
+  machine_mode mode = TYPE_MODE (type);
+  const tree bool_type = boolean_type_node;
+
+  if (!HONOR_NANS (arg) && !HONOR_INFINITIES (arg))
+    {
+      return build_int_cst (bool_type, true);
+    }
+
+  /* If not using optimized route then exit early.  */
+  if (!use_ieee_int_mode (arg))
+    {
+
+      /* Perform IBM extended format fixups if required.  */
+      perform_ibm_extended_fixups (&arg, &mode, &type, loc);
+
+      tree const isle_fn = builtin_decl_explicit (BUILT_IN_ISLESSEQUAL);
+
+      tree arg_p
+	= emit_tree_and_return_var (seq, fold_build1_loc (loc, ABS_EXPR, type,
+							  arg));
+      REAL_VALUE_TYPE rmax;
+      char buf[128];
+      get_max_float (REAL_MODE_FORMAT (mode), buf, sizeof (buf));
+      real_from_string (&rmax, buf);
+
+      tree res = build_call_expr (isle_fn, 2,  arg_p, build_real (type, rmax));
+
+      push_gimplify_context ();
+      gimplify_expr (&res, seq, NULL, is_gimple_val, fb_either);
+      pop_gimplify_context (NULL);
+
+      return emit_tree_and_return_var (seq, gimple_boolify(res));
+    }
+
+  const real_format *format = REAL_MODE_FORMAT (mode);
+  const HOST_WIDE_INT type_width = TYPE_PRECISION (type);
+
+  tree int_arg_type = build_nonstandard_integer_type (type_width, true);
+
+  /* This creates a mask to be used to check the exp value in the shifted
+     integer representation of the fpnum.  */
+  const int exp_bits  = (GET_MODE_SIZE (mode) * BITS_PER_UNIT) - format->p;
+  gcc_assert (format->p > 0);
+
+  tree significant_bit = build_int_cstu (int_arg_type, format->p);
+  tree exp_mask
+    = fold_build2_loc (loc, MINUS_EXPR, int_arg_type,
+		       fold_build2_loc (loc, LSHIFT_EXPR, int_arg_type,
+					build_int_cstu (int_arg_type, 2),
+					build_int_cstu (int_arg_type,
+							exp_bits - 1)),
+		       build_int_cstu (int_arg_type, 1));
+
+  /* Get the number reinterpreted as an integer.
+     Shift left to remove the sign. */
+  tree int_arg
+    = fold_build2_loc (loc, LSHIFT_EXPR, int_arg_type,
+		       get_num_as_int (seq, arg, loc),
+		       build_int_cstu (int_arg_type, 1));
+
+  /* This mask checks to see if the exp has all bits set and mantissa no
+     bits set.  */
+  tree inf_mask
+    = fold_build2_loc (loc, LSHIFT_EXPR, int_arg_type,
+		       exp_mask, significant_bit);
+
+  /* Check if exponent has all bits set and mantissa is 0. */
+  tree inf_check_tmp
+    = fold_build2_loc (loc, LT_EXPR, bool_type,
+		       emit_tree_and_return_var (seq, int_arg),
+		       inf_mask);
+
+  tree inf_check = emit_tree_and_return_var (seq, inf_check_tmp);
+
+  return emit_tree_and_return_var (seq, inf_check);
+}
+
+/* Generates code to check if ARG is a NaN. In the FP case we simply check if
+   ARG != ARG and in the INT case we check the bits in the exp and mantissa.
+   Returns a variable containing a boolean which has the result of the check.
+
+   SEQ is the buffer to use to emit the gimple instructions into.
+   LOC is the location to use during fold calls.  */
+static tree
+is_nan (gimple_seq *seq, tree arg, location_t loc)
+{
+  tree type = TREE_TYPE (arg);
+
+  machine_mode mode = TYPE_MODE (type);
+  const tree bool_type = boolean_type_node;
+
+  if (!HONOR_NANS (mode))
+    {
+      return build_int_cst (bool_type, false);
+    }
+
+  const real_format *format = REAL_MODE_FORMAT (mode);
+
+  /* If not using optimized route then exit early.  */
+  if (!use_ieee_int_mode (arg))
+    {
+      /* Perform IBM extended format fixups if required.  */
+      perform_ibm_extended_fixups (&arg, &mode, &type, loc);
+
+      tree arg_p
+	= emit_tree_and_return_var (seq, fold_build1_loc (loc, ABS_EXPR, type,
+							  arg));
+      tree res
+	= fold_build2_loc (loc, UNORDERED_EXPR, bool_type,arg_p, arg_p);
+
+      return emit_tree_and_return_var (seq, res);
+  }
+
+  const HOST_WIDE_INT type_width = TYPE_PRECISION (type);
+  tree int_arg_type = build_nonstandard_integer_type (type_width, true);
+
+  /* This creates a mask to be used to check the exp value in the shifted
+     integer representation of the fpnum.  */
+  const int exp_bits  = (GET_MODE_SIZE (mode) * BITS_PER_UNIT) - format->p;
+  tree significant_bit = build_int_cstu (int_arg_type, format->p);
+  tree exp_mask
+    = fold_build2_loc (loc, MINUS_EXPR, int_arg_type,
+		       fold_build2_loc (loc, LSHIFT_EXPR, int_arg_type,
+					build_int_cstu (int_arg_type, 2),
+					build_int_cstu (int_arg_type,
+							exp_bits - 1)),
+		       build_int_cstu (int_arg_type, 1));
+
+  /* Get the number reinterpreted as an integer.
+     Shift left to remove the sign.  */
+  tree int_arg
+    = fold_build2_loc (loc, LSHIFT_EXPR, int_arg_type,
+		       get_num_as_int (seq, arg, loc),
+		       build_int_cstu (int_arg_type, 1));
+
+  /* This mask checks to see if the exp has all bits set and mantissa no
+     bits set.  */
+  tree inf_mask
+    = fold_build2_loc (loc, LSHIFT_EXPR, int_arg_type,
+		       exp_mask, significant_bit);
+
+  /* Check if exponent has all bits set and mantissa is not 0.  */
+  tree nan_check
+    = emit_tree_and_return_var(seq,
+	fold_build2_loc (loc, GT_EXPR, bool_type,
+			 emit_tree_and_return_var(seq, int_arg),
+			 inf_mask));
+
+  return emit_tree_and_return_var (seq, nan_check);
+}
+
+/* Validates a single argument from the arguments list CALL at position INDEX.
+   The extracted parameter is compared against the expected type CODE.
+
+   A boolean is returned indicating if the parameter exist and if of the
+   expected type.  */
+static bool
+gimple_validate_arg (gimple* call, int index, enum tree_code code)
+{
+  const tree arg = gimple_call_arg (call, index);
+  if (!arg)
+    return false;
+  else if (code == POINTER_TYPE)
+    return POINTER_TYPE_P (TREE_TYPE (arg));
+  else if (code == INTEGER_TYPE)
+    return INTEGRAL_TYPE_P (TREE_TYPE (arg));
+  return code == TREE_CODE (TREE_TYPE (arg));
+}
+
+/* Lowers calls to __builtin_fpclassify to
+   fpclassify (x) ->
+     isnormal(x) ? FP_NORMAL :
+       iszero (x) ? FP_ZERO :
+	 isnan (x) ? FP_NAN :
+	   isinfinite (x) ? FP_INFINITE :
+	     FP_SUBNORMAL.
+
+   The code may use integer arithmentic if it decides
+   that the produced assembly would be faster. This can only be done
+   for numbers that are similar to IEEE-754 in format.
+
+   This builtin will generate code to return the appropriate floating
+   point classification depending on the value of the floating point
+   number passed in.  The possible return values must be supplied as
+   int arguments to the call in the following order: FP_NAN, FP_INFINITE,
+   FP_NORMAL, FP_SUBNORMAL and FP_ZERO.  The ellipses is for exactly
+   one floating point argument which is "type generic".
+
+   GSI is the gimple iterator containing the fpclassify call to lower.
+   The call will be expanded and replaced inline in the given GSI.  */
+static void
+lower_builtin_fpclassify (gimple_stmt_iterator *gsi)
+{
+  gimple *call = gsi_stmt (*gsi);
+  location_t loc = gimple_location (call);
+
+  /* Verify the required arguments in the original call.  */
+  if (gimple_call_num_args (call) != 6
+      || !gimple_validate_arg (call, 0, INTEGER_TYPE)
+      || !gimple_validate_arg (call, 1, INTEGER_TYPE)
+      || !gimple_validate_arg (call, 2, INTEGER_TYPE)
+      || !gimple_validate_arg (call, 3, INTEGER_TYPE)
+      || !gimple_validate_arg (call, 4, INTEGER_TYPE)
+      || !gimple_validate_arg (call, 5, REAL_TYPE))
+    return;
+
+  /* Collect the arguments from the call.  */
+  tree fp_nan = gimple_call_arg (call, 0);
+  tree fp_infinite = gimple_call_arg (call, 1);
+  tree fp_normal = gimple_call_arg (call, 2);
+  tree fp_subnormal = gimple_call_arg (call, 3);
+  tree fp_zero = gimple_call_arg (call, 4);
+  tree arg = gimple_call_arg (call, 5);
+
+  gimple_seq body = NULL;
+
+  /* Create label to jump to to exit.  */
+  tree done_label = create_artificial_label (UNKNOWN_LOCATION);
+  tree dest;
+  tree orig_dest = dest = gimple_call_lhs (call);
+  if (orig_dest && TREE_CODE (orig_dest) == SSA_NAME)
+    dest = create_tmp_reg (TREE_TYPE (orig_dest));
+
+  emit_tree_cond (&body, dest, done_label,
+		  is_normal (&body, arg, loc), fp_normal);
+  emit_tree_cond (&body, dest, done_label,
+		  is_zero (&body, arg, loc), fp_zero);
+  emit_tree_cond (&body, dest, done_label,
+		  is_nan (&body, arg, loc), fp_nan);
+  emit_tree_cond (&body, dest, done_label,
+		  is_infinity (&body, arg, loc), fp_infinite);
+
+  /* And finally, emit the default case if nothing else matches.
+     This replaces the call to is_subnormal.  */
+  gimple_seq_add_stmt (&body, gimple_build_assign (dest, fp_subnormal));
+  gimple_seq_add_stmt (&body, gimple_build_label (done_label));
+
+  /* Build orig_dest = dest if necessary.  */
+  if (dest != orig_dest)
+    {
+      gimple_seq_add_stmt (&body, gimple_build_assign (orig_dest, dest));
+    }
+
+  gsi_insert_seq_before (gsi, body, GSI_SAME_STMT);
+
+
+  /* Remove the call to __builtin_fpclassify.  */
+  gsi_remove (gsi, false);
+}
+
+/* Generic wrapper for the is_nan, is_normal, is_subnormal, is_zero, etc.
+   All these functions have the same setup. The wrapper validates the parameter
+   and also creates the branches and labels required to properly invoke.
+   This has been generalize and the function to call is passed as argument FNDECL.
+
+   GSI is the gimple iterator containing the fpclassify call to lower.
+   The call will be expanded and replaced inline in the given GSI.  */
+static void
+gen_call_fp_builtin (gimple_stmt_iterator *gsi,
+		     tree (*fndecl)(gimple_seq *, tree, location_t))
+{
+  gimple *call = gsi_stmt (*gsi);
+  location_t loc = gimple_location (call);
+
+  /* Verify the required arguments in the original call.  */
+  if (gimple_call_num_args (call) != 1
+      || !gimple_validate_arg (call, 0, REAL_TYPE))
+    return;
+
+  tree arg = gimple_call_arg (call, 0);
+  gimple_seq body = NULL;
+
+  /* Create label to jump to to exit.  */
+  tree done_label = create_artificial_label (UNKNOWN_LOCATION);
+  tree dest;
+  tree orig_dest = dest = gimple_call_lhs (call);
+  tree type = TREE_TYPE (orig_dest);
+  if (orig_dest && TREE_CODE (orig_dest) == SSA_NAME)
+      dest = create_tmp_reg (type);
+
+  tree t_true = build_int_cst (type, true);
+  tree t_false = build_int_cst (type, false);
+
+  emit_tree_cond (&body, dest, done_label,
+		  fndecl (&body, arg, loc), t_true);
+
+  /* And finally, emit the default case if nothing else matches.
+     This replaces the call to false.  */
+  gimple_seq_add_stmt (&body, gimple_build_assign (dest, t_false));
+  gimple_seq_add_stmt (&body, gimple_build_label (done_label));
+
+  /* Build orig_dest = dest if necessary.  */
+  if (dest != orig_dest)
+  {
+    gimple_seq_add_stmt (&body, gimple_build_assign (orig_dest, dest));
+  }
+
+  gsi_insert_seq_before (gsi, body, GSI_SAME_STMT);
+
+  /* Remove the call to the builtin.  */
+  gsi_remove (gsi, false);
+}
+
+/* Lower and expand calls to __builtin_isnan in GSI.  */
+static void
+lower_builtin_isnan (gimple_stmt_iterator *gsi)
+{
+  gen_call_fp_builtin (gsi, &is_nan);
+}
+
+/* Lower and expand calls to __builtin_isinfinite in GSI.  */
+static void
+lower_builtin_isinfinite (gimple_stmt_iterator *gsi)
+{
+  gen_call_fp_builtin (gsi, &is_infinity);
+}
+
+/* Lower and expand calls to __builtin_isnormal in GSI.  */
+static void
+lower_builtin_isnormal (gimple_stmt_iterator *gsi)
+{
+  gen_call_fp_builtin (gsi, &is_normal);
+}
+
+/* Lower and expand calls to __builtin_iszero in GSI.  */
+static void
+lower_builtin_iszero (gimple_stmt_iterator *gsi)
+{
+  gen_call_fp_builtin (gsi, &is_zero);
+}
+
+/* Lower and expand calls to __builtin_issubnormal in GSI.  */
+static void
+lower_builtin_issubnormal (gimple_stmt_iterator *gsi)
+{
+  gen_call_fp_builtin (gsi, &is_subnormal);
+}
+
+/* Lower and expand calls to __builtin_isfinite in GSI.  */
+static void
+lower_builtin_isfinite (gimple_stmt_iterator *gsi)
+{
+  gen_call_fp_builtin (gsi, &is_finite);
+}
+
 /* Lower calls to posix_memalign to
      res = posix_memalign (ptr, align, size);
      if (res == 0)