PR target/PR54461

	PR target/PR54461
	* doc/install.texi (Cross-Compiler-Specific Options): Document
	--with-avrlibc.

From-SVN: r194978

gcc/ChangeLog

+2013-01-07  Georg-Johann Lay  <avr@gjlay.de>
+
+	PR target/PR54461
+	* doc/install.texi (Cross-Compiler-Specific Options): Document
+	--with-avrlibc.
+
 2013-01-07  Tejas Belagod  <tejas.belagod@arm.com>
 
 	* config/aarch64/arm_neon.h (vmovn_high_is16, vmovn_high_s32,

gcc/doc/install.texi

@@ -1813,6 +1813,16 @@ being used as the target C library.  This causes @code{__eprintf} to be
 omitted from @file{libgcc.a} on the assumption that it will be provided by
 @samp{newlib}.
 
+@item --with-avrlibc
+Specifies that @samp{AVR-Libc} is
+being used as the target C library.  This causes float support
+functions like @code{__addsf3} to be omitted from @file{libgcc.a} on
+the assumption that it will be provided by @file{libm.a}.  For more
+technical details, cf. @uref{http://gcc.gnu.org/PR54461,,PR54461}.
+This option is only supported for the AVR target.  It is not supported for
+RTEMS configurations, which currently use newlib.  The option is
+supported since version 4.7.2 and is the default in 4.8.0 and newer.
+
 @item --with-build-time-tools=@var{dir}
 Specifies where to find the set of target tools (assembler, linker, etc.)
 that will be used while building GCC itself.  This option can be useful