Add the <tgmath.h> header containing type-generic math macros.

So far this only has macros for the newly-added functions, since the existing math functions in SysFloat do not have f- and l-suffixed versions.

ORCACDefs/tgmath.h

@@ -0,0 +1,57 @@
+/****************************************************************
+*
+*  tgmath.h - type-generic math macros
+*
+*  November 2021
+*  Stephen Heumann
+*
+****************************************************************/
+
+#ifndef __tgmath__
+#define __tgmath__
+
+#include <math.h>
+
+/*
+ * Note: This header currently contains only some of the macros specified
+ * in the C99 and later standards.  Others are not present because the
+ * corresponding functions either are not available at all or have only
+ * an unsuffixed version available.
+ */
+
+#define __tg_real_x(fn,x) _Generic((x), \
+   float: fn##f, \
+   long double: fn##l, \
+   default: fn)(x)
+
+#define __tg_real_x_other(fn,x,other) _Generic((x), \
+   float: fn##f, \
+   long double: fn##l, \
+   default: fn)((x),(other))
+
+#define __tg_real_x_y(fn,x,y) _Generic((x), \
+   float: _Generic((y), float: fn##f, long double: fn##l, default: fn), \
+   long double: fn##l, \
+   default: _Generic((y), long double: fn##l, default: fn))((x),(y))
+
+#define __tg_real_x_y_other(fn,x,y,other) _Generic((x), \
+   float: _Generic((y), float: fn##f, long double: fn##l, default: fn), \
+   long double: fn##l, \
+   default: _Generic((y), long double: fn##l, default: fn))((x),(y),(other))
+
+#define cbrt(x)         __tg_real_x(cbrt,(x))
+#define copysign(x,y)   __tg_real_x_y(copysign,(x),(y))
+#define exp2(x)         __tg_real_x(exp2,(x))
+#define expm1(x)        __tg_real_x(expm1,(x))
+#define ilogb(x)        __tg_real_x(ilogb,(x))
+#define log1p(x)        __tg_real_x(log1p,(x))
+#define log2(x)         __tg_real_x(log2,(x))
+#define logb(x)         __tg_real_x(logb,(x))
+#define lrint(x)        __tg_real_x(lrint,(x))
+#define remainder(x,y)  __tg_real_x_y(remainder,(x),(y))
+#define remquo(x,y,quo) __tg_real_x_y_other(remquo,(x),(y),(quo))
+#define rint(x)         __tg_real_x(rint,(x))
+#define scalbn(x,n)     __tg_real_x_other(scalbn,(x),(n))
+#define trunc(x)        __tg_real_x(trunc,(x))
+
+#endif

cc.notes

@@ -617,6 +617,8 @@ ORCA/C now includes several new headers specified by recent C standards.
 
 9.  (C11) The <uchar.h> header defines the types char16_t and char32_t suitable for holding UTF-16 and UTF-32 code units, and provides functions for handling Unicode characters.
 
+10. (C99) The <tgmath.h> header contains type-generic macros that can invoke the float, double, or long double versions of certain math functions, as determined based on the types of the arguments passed to them.
+
 
 Library Updates
 ---------------