* gcc.texi: Document recommend means to provide software floating

        point libraries in libgcc.a


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@28565 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 23 insertions, 0 deletions

diff --git a/gcc/gcc.texi b/gcc/gcc.texi
index b9823fa8eb0..8d54b8d3bed 100644
--- a/gcc/gcc.texi
+++ b/gcc/gcc.texi
@@ -3929,6 +3929,29 @@ Compiler flags to use when compiling @file{libgcc2.c}.
 A list of source file names to be compiled or assembled and inserted
 into @file{libgcc.a}.
 
+@findex Floating Point Emulation
+@item Floating Point Emulation
+To have GCC include software floating point libraries in @file{libgcc.a}
+define @code{FPBIT} and @code{DPBIT} along with a few rules as follows:
+@smallexample
+# We want fine grained libraries, so use the new code to build the
+# floating point emulation libraries.
+FPBIT = fp-bit.c
+DPBIT = dp-bit.c
+
+
+fp-bit.c: $(srcdir)/config/fp-bit.c
+        echo '#define FLOAT' > fp-bit.c
+        cat $(srcdir)/config/fp-bit.c >> fp-bit.c
+
+dp-bit.c: $(srcdir)/config/fp-bit.c
+        cat $(srcdir)/config/fp-bit.c > dp-bit.c
+@end smallexample
+
+You may need to provide additional #defines at the beginning of @file{fp-bit.c}
+and @file{dp-bit.c} to control target endianness and other options.
+
+
 @findex CRTSTUFF_T_CFLAGS
 @item CRTSTUFF_T_CFLAGS
 Special flags used when compiling @file{crtstuff.c}.