real.c (real_copysign): New function to implement libm's copysign.

	* real.c (real_copysign): New function to implement libm's copysign.
	* real.h (real_copysign): Prototype here.
	* fold-const.c (tree_expr_nonnegative_p): The result of sqrt, sqrtf
	and sqrtl can be negative, as sqrt(-0.0) = -0.0.  Correct whitespace.
	* builtins.c (fold_builtin_isascii, fold_builtin_toascii,
	fold_builtin_isdigit): Add function prototypes.
	(fold_builtin_copysign): New function to fold copysign, copysignf
	and copysignl.  Optimize copysign(x,x) as x.  Evaluate copysign of
	constant arguments at compile-time using real_copysign.  Fold
	copysign(X,Y) as fabs(X) if Y is always non-negative.
	(fold_builtin_1): Correct minor whitespace/style issues.  Call
	fold_builtin_copysign for BUILT_IN_COPYSIGN{,F,L}.

	* gcc.dg/builtins-41.c: New test case.
	* gcc.dg/builtins-42.c: New test case.

From-SVN: r82721

1 files changed, 8 insertions, 0 deletions

diff --git a/gcc/real.c b/gcc/real.c
index e702b2d..65d57c3 100644
--- a/gcc/real.c
+++ b/gcc/real.c
@@ -4587,3 +4587,11 @@ real_round (REAL_VALUE_TYPE *r, enum machine_mode mode,
     real_convert (r, mode, r);
 }
 
+/* Set the sign of R to the sign of X.  */
+
+void
+real_copysign (REAL_VALUE_TYPE *r, const REAL_VALUE_TYPE *x)
+{
+  r->sign = x->sign;
+}
+