EP9312 gcc: undefined reference to __divdf3

[Wouter van Heyst <wouter at vidicode dot org>]

Hello all,

I'm running into a problem trying to make a gcc 3.4.0 based toolchain
with MaverickCrunch support, during the final linkage of libc.so,
several functions turn up undefined references to __divdf3.

I think Richard Earnshaw and Vladimir Ivanov have spoken about this:
	http://gcc.gnu.org/ml/gcc-patches/2004-03/msg00513.html

other than that thread I can't find a lot of references, neither is it
clear if Nucleusys have their copyright assignment yet, nor what the
current status is for the Cirrus ep9312 processor.

Anyway, trying to reproduce my problem I configured gcc seperately.
Multilib options in gcc/config/arm/t-arm-elf are uncommented per
http://gcc.gnu.org/gcc-3.4/changes.html:

	MULTILIB_OPTIONS    += mcpu=ep9312
	MULTILIB_DIRNAMES   += ep9312
	MULTILIB_EXCEPTIONS += *mthumb/*mcpu=ep9312*

(no divdf3 mentioned in LIB1ASMFUNCS in that file, should it?)

Configured thusly:

../gcc-3.4.0/configure --target=arm-ep93xx-linux-gnu --host=powerpc-linux
--prefix=/opt/crosstool/arm-ep93xx-linux-gnu/gcc-3.4.0-glibc-2.3.2
--with-local-prefix=/opt/crosstool/arm-ep93xx-linux-gnu/gcc-3.4.0-glibc-2.3.2/arm-ep93xx-linu-gnu
--with-newlib --disable-nls --with-cpu=ep9312 --enable-threads=no
--enable-symvers=gnu --enable-__cxa_atexit --enable-languages=c
--disable-shared --enable-cxx-flags=-mcpu=ep9312

Followed by:
	make all-gcc
	make install-gcc

Results in a semi-working toolchain:

	# cat test.c
	int bar(float foo) {
			float c = foo / 12.34;
	}

	int _start() {
			bar(2);
	}
	# arm-ep93xx-linux-gnu-gcc test.c -nostdlib
	/tmp/cc2t8YCe.o(.text+0x2c): In function `bar':
	: undefined reference to `__divdf3'
	collect2: ld returned 1 exit status


Assembly:
	str r0, [fp, #-16]  @ float
    cfldrs  mvf0, [fp, #-16]
    cfcvtsd mvd0, mvf0
    cfmvrdl r0, mvd0
    cfmvrdh r1, mvd0
    adr r2, .L2
    ldmia   r2, {r2-r3}
    bl  __divdf3
    cfcvtds mvf0, mvd0
    cfstrs  mvf0, [fp, #-20]


Richard Earnshaw commented the divdf3 define_expand pattern might need
disabling, should I try that? I'm not well versed in gcc internals, but
I'm eager to tackle this. Pointers are greatly appreciated.

Of course, it's possible this is not a gcc bug, and I messed up,
pointing that out is welcome too :)

Wouter van Heyst