* defaults.h (MODE_HAS_NANS, MODE_HAS_INFINITIES): New.

	(MODE_HAS_SIGNED_ZEROS, MODE_HAS_SIGN_DEPENDENT_ROUNDING): New.
	* flags.h (HONOR_NANS, HONOR_INFINITIES, HONOR_SIGNED_ZEROS): New.
	(HONOR_SIGN_DEPENDENT_ROUNDING): New.
	* builtins.c (expand_builtin_mathfn): Use HONOR_NANS.
	* c-common.c (truthvalue_conversion): Reduce x - y != 0 to x != y
	unless x and y could be infinite.
	(expand_unordered_cmp): New, mostly split from expand_tree_builtin.
	Check that the common type of both arguments is a real, even for
	targets without unordered comparisons.  Allow an integer argument
	to be compared against a real.
	(expand_tree_builtin): Use expand_unordered_cmp.
	* combine.c (combine_simplify_rtx): Use the new HONOR_... macros.
	* cse.c (fold_rtx): Likewise.  Fix indentation.
	* fold-const.c (fold_real_zero_addition_p): New.
	(fold): Use it, and the new HONOR_... macros.
	* ifcvt.c (noce_try_minmax): Use the new HONOR_... macros.
	* jump.c (reversed_comparison_code_parts): After searching for
	the true comparison mode, use HONOR_NANS to decide whether it
	can be safely reversed.
	(reverse_condition_maybe_unordered): Remove IEEE check.
	* simplify-rtx.c (simplify_binary_operation): Use the new macros
	to decide which simplifications are valid.  Allow the following
	simplifications for IEEE: (-a + b) to (b - a), (a + -b) to (a - b),
	and (a - -b) to (a + b).
	(simplify_relational_operation): Use HONOR_NANS.
	* doc/tm.texi: Document the MODE_HAS_... macros.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@50401 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 12 insertions, 13 deletions

diff --git a/gcc/cse.c b/gcc/cse.c
index 7a05dad0307..1fe4752d8a0 100644
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -3981,19 +3981,18 @@ fold_rtx (x, insn)
 					& HASH_MASK), mode_arg0))
 		      && p0->first_same_value == p1->first_same_value))
 		{
-		   /* Sadly two equal NaNs are not equivalent.  */
-		   if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
-		       || ! FLOAT_MODE_P (mode_arg0) 
-		       || flag_unsafe_math_optimizations)
-		      return ((code == EQ || code == LE || code == GE
-			       || code == LEU || code == GEU || code == UNEQ
-			       || code == UNLE || code == UNGE || code == ORDERED)
-			      ? true_rtx : false_rtx);
-		   /* Take care for the FP compares we can resolve.  */
-		   if (code == UNEQ || code == UNLE || code == UNGE)
-		     return true_rtx;
-		   if (code == LTGT || code == LT || code == GT)
-		     return false_rtx;
+		  /* Sadly two equal NaNs are not equivalent.  */
+		  if (!HONOR_NANS (mode_arg0))
+		    return ((code == EQ || code == LE || code == GE
+			     || code == LEU || code == GEU || code == UNEQ
+			     || code == UNLE || code == UNGE
+			     || code == ORDERED)
+			    ? true_rtx : false_rtx);
+		  /* Take care for the FP compares we can resolve.  */
+		  if (code == UNEQ || code == UNLE || code == UNGE)
+		    return true_rtx;
+		  if (code == LTGT || code == LT || code == GT)
+		    return false_rtx;
 		}
 
 	      /* If FOLDED_ARG0 is a register, see if the comparison we are