re PR middle-end/35509 (builtin isinf() mismatch to compile-time substitution)

	PR middle-end/35509

	* builtins.c (mathfn_built_in_1): Renamed from mathfn_built_in.
	Add `implicit' parameter.  Handle BUILT_IN_SIGNBIT.
	(mathfn_built_in): Rewrite in terms of mathfn_built_in_1.
	(fold_builtin_classify): Handle BUILT_IN_ISINF_SIGN.
	(fold_builtin_1): Likewise.
	* builtins.def (BUILT_IN_ISINF_SIGN): New.
	c-common.c (check_builtin_function_arguments): Handle
	BUILT_IN_ISINF_SIGN.
	* doc/extend.texi: Document __builtin_isinf_sign.
	* fold-const.c (operand_equal_p): Handle COND_EXPR.

testsuite:
	* gcc.dg/builtins-error.c: Test __builtin_isinf_sign.
	* gcc.dg/tg-tests.h: Likewise.  Mark variables volatile.
	* gcc.dg/torture/builtin-isinf_sign-1.c: New test.

From-SVN: r135517

1 files changed, 13 insertions, 2 deletions

diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index f3c6c57..36e81ff 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -5768,6 +5768,7 @@ should be called and the @var{flag} argument passed to it.
 @findex __builtin_isnormal
 @findex __builtin_isgreater
 @findex __builtin_isgreaterequal
+@findex __builtin_isinf_sign
 @findex __builtin_isless
 @findex __builtin_islessequal
 @findex __builtin_islessgreater
@@ -6294,8 +6295,10 @@ the same names as the standard macros ( @code{isgreater},
 @code{islessgreater}, and @code{isunordered}) , with @code{__builtin_}
 prefixed.  We intend for a library implementor to be able to simply
 @code{#define} each standard macro to its built-in equivalent.
-In the same fashion, GCC provides @code{isfinite} and @code{isnormal}
-built-ins used with @code{__builtin_} prefixed.
+In the same fashion, GCC provides @code{isfinite}, @code{isinf_sign}
+and @code{isnormal} built-ins used with @code{__builtin_} prefixed.
+The @code{isinf} and @code{isnan} builtins appear both with and
+without the @code{__builtin_} prefix.
 
 @deftypefn {Built-in Function} int __builtin_types_compatible_p (@var{type1}, @var{type2})
 
@@ -6579,6 +6582,14 @@ Similar to @code{__builtin_inf}, except the return
 type is @code{long double}.
 @end deftypefn
 
+@deftypefn {Built-in Function} int __builtin_isinf_sign (...)
+Similar to @code{isinf}, except the return value will be negative for
+an argument of @code{-Inf}.  Note while the parameter list is an
+ellipsis, this function only accepts exactly one floating point
+argument.  GCC treats this parameter as type-generic, which means it
+does not do default promotion from float to double.
+@end deftypefn
+
 @deftypefn {Built-in Function} double __builtin_nan (const char *str)
 This is an implementation of the ISO C99 function @code{nan}.