diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 632a241a964..b76e80c02a3 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -12007,8 +12007,8 @@ fold_binary_loc (location_t loc, enum tree_code code, tree type,
       strict_overflow_p = false;
       if (code == GE_EXPR
 	  && (integer_zerop (arg1)
-	      || (! HONOR_NANS (arg0)
-		  && real_zerop (arg1)))
+	      || (real_zerop (arg1)
+		  && !tree_expr_maybe_nan_p (arg0)))
 	  && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
 	{
 	  if (strict_overflow_p)
@@ -12024,7 +12024,10 @@ fold_binary_loc (location_t loc, enum tree_code code, tree type,
       /* Convert ABS_EXPR<x> < 0 to false.  */
       strict_overflow_p = false;
       if (code == LT_EXPR
-	  && (integer_zerop (arg1) || real_zerop (arg1))
+	  && (integer_zerop (arg1)
+	      || (real_zerop (arg1)
+		  && (!flag_trapping_math
+		      || !tree_expr_maybe_nan_p (arg0))))
 	  && tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
 	{
 	  if (strict_overflow_p)
diff --git a/gcc/match.pd b/gcc/match.pd
index b6dfc24af88..ef1bfb42d12 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -4037,7 +4037,10 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
     (cmp @0 { build_real (TREE_TYPE (@1), dconst0); }))
    /* x != NaN is always true, other ops are always false.  */
    (if (REAL_VALUE_ISNAN (TREE_REAL_CST (@1))
-	&& ! HONOR_SNANS (@1))
+	&& (!flag_trapping_math
+	    || ((cmp == EQ_EXPR || cmp == NE_EXPR)
+		&& !tree_expr_maybe_signaling_nan_p (@1)
+		&& !tree_expr_maybe_signaling_nan_p (@0))))
     { constant_boolean_node (cmp == NE_EXPR, type); })
    /* Fold comparisons against infinity.  */
    (if (REAL_VALUE_ISINF (TREE_REAL_CST (@1))
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c
index 47e7aebda8a..dd97a353bff 100644
--- a/gcc/simplify-rtx.c
+++ b/gcc/simplify-rtx.c
@@ -5732,20 +5732,31 @@ simplify_const_relational_operation (enum rtx_code code,
       if (REAL_VALUE_ISNAN (*d0) || REAL_VALUE_ISNAN (*d1))
 	switch (code)
 	  {
+	  case NE:
+	    if (flag_trapping_math
+		&& (REAL_VALUE_ISSIGNALING_NAN (*d0)
+		    || REAL_VALUE_ISSIGNALING_NAN (*d1)))
+	      return 0;
+	    return const_true_rtx;
 	  case UNEQ:
 	  case UNLT:
 	  case UNGT:
 	  case UNLE:
 	  case UNGE:
-	  case NE:
 	  case UNORDERED:
 	    return const_true_rtx;
 	  case EQ:
+	    if (flag_trapping_math
+		&& (REAL_VALUE_ISSIGNALING_NAN (*d0)
+		    || REAL_VALUE_ISSIGNALING_NAN (*d1)))
+	      return 0;
+	    return const0_rtx;
 	  case LT:
 	  case GT:
 	  case LE:
 	  case GE:
 	  case LTGT:
+	    return flag_trapping_math ? 0 : const0_rtx;
 	  case ORDERED:
 	    return const0_rtx;
 	  default: