Simplify INFINITY definitions.

Similar to my patch for HUGE_VAL, this patch eliminates the bits/inf.h
headers and just unconditionally uses the same definitions as the
sysdeps/ieee754 version did (__builtin_inff () for GCC >= 3.3,
otherwise HUGE_VALF), directly in math.h, so removing an unnecessary
level of indirection.

Tested for x86_64.

	* math/math.h [__USE_ISOC99] (INFINITY): Define directly here.  Do
	not include <bits/inf.h>.
	* math/Makefile (headers): Remove bits/inf.h.
	* bits/inf.h: Remove.
	* sysdeps/ieee754/bits/inf.h: Likewise.

5 files changed, 13 insertions, 64 deletions

diff --git a/ChangeLog b/ChangeLog
index e7849b1..904d375 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2017-08-31  Joseph Myers  <joseph@codesourcery.com>
 
+	* math/math.h [__USE_ISOC99] (INFINITY): Define directly here.  Do
+	not include <bits/inf.h>.
+	* math/Makefile (headers): Remove bits/inf.h.
+	* bits/inf.h: Remove.
+	* sysdeps/ieee754/bits/inf.h: Likewise.
+
 	* math/math.h: Do not include bits/huge_val.h, bits/huge_valf.h,
 	bits/huge_vall.h or bits/huge_val_flt128.h.
 	(HUGE_VAL): Define directly here.
diff --git a/bits/inf.h b/bits/inf.h
deleted file mode 100644
index 5c66ca3..0000000
--- a/bits/inf.h
+++ /dev/null
@@ -1,32 +0,0 @@
-/* Default `INFINITY' constant.
-   Copyright (C) 2004-2017 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#ifndef _MATH_H
-# error "Never use <bits/inf.h> directly; include <math.h> instead."
-#endif
-
-/* If we don't have real infinity, then we're supposed to produce a float
-   value that overflows at translation time, which is required to produce
-   a diagnostic.  GCC's __builtin_inff produces a quite nice diagnostic
-   that tells the user that the target doesn't support infinities.  */
-
-#if __GNUC_PREREQ(3,3)
-# define INFINITY	(__builtin_inff())
-#else
-# define INFINITY	(1e9999f)
-#endif
diff --git a/math/Makefile b/math/Makefile
index 01345fb..b9a06f0 100644
--- a/math/Makefile
+++ b/math/Makefile
@@ -23,7 +23,7 @@ include ../Makeconfig
 
 # Installed header files.
 headers		:= math.h bits/mathcalls.h bits/mathinline.h \
-		   bits/inf.h bits/nan.h \
+		   bits/nan.h \
 		   fpu_control.h complex.h bits/cmathcalls.h fenv.h \
 		   bits/fenv.h bits/fenvinline.h bits/mathdef.h tgmath.h \
 		   bits/math-finite.h bits/math-vector.h \
diff --git a/math/math.h b/math/math.h
index dcccf8e..5f5a498 100644
--- a/math/math.h
+++ b/math/math.h
@@ -58,8 +58,12 @@ __BEGIN_DECLS
 #endif
 
 #ifdef __USE_ISOC99
-/* Get machine-dependent INFINITY value.  */
-# include <bits/inf.h>
+/* IEEE positive infinity.  */
+# if __GNUC_PREREQ (3, 3)
+#  define INFINITY (__builtin_inff ())
+# else
+#  define INFINITY HUGE_VALF
+# endif
 
 /* Get machine-dependent NAN value (returned for some domain errors).  */
 # include <bits/nan.h>
diff --git a/sysdeps/ieee754/bits/inf.h b/sysdeps/ieee754/bits/inf.h
deleted file mode 100644
index eee0f2e..0000000
--- a/sysdeps/ieee754/bits/inf.h
+++ /dev/null
@@ -1,29 +0,0 @@
-/* `INFINITY' constant for IEEE 754 machines.
-   Copyright (C) 2004-2017 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#ifndef _MATH_H
-# error "Never use <bits/inf.h> directly; include <math.h> instead."
-#endif
-
-/* IEEE positive infinity.  */
-
-#if __GNUC_PREREQ(3,3)
-# define INFINITY	(__builtin_inff())
-#else
-# define INFINITY	HUGE_VALF
-#endif