[Bug target/16314] New: EP9312 gcc: undefined reference to __divdf3

[Bug target/16314] New: EP9312 gcc: undefined reference to __divdf3

[wouter at vidicode dot org]

Trying to compile some simple floating point math using the Maverick Crunch
coprocessor on the EP9312 breaks because the divide functions end up in the
assemby but aren't in libcc. As far as I understand it, the problem stems from
the Crunch core not supporting floating point divide, and then we get into ABI
differences (returning values in integer/float point registers). More (accurate)
information can be found in the thread on the gcc ml:

thread start: http://gcc.gnu.org/ml/gcc/2004-06/msg01867.html
continued into the next month: http://gcc.gnu.org/ml/gcc/2004-07/msg00028.html


simple test case to reproduce the problem:

double x, y;  float a, b;
int main () { a = a/b; x = x /y; return 0; }

compiler commandline and output:

# arm-ep93xx-linux-gnu-gcc bug.c -Wall -nostdlib                               
                                                                                   
/home/larstiq/crosstool/arm-ep93xx-linux-gnu/gcc-3.4.0-glibc-2.3.2/bin/../lib/gcc/arm-ep93xx-linux-gnu/3.4.0/../../../../arm-ep93xx-linux-gnu/bin/ld:
warning: cannot find entry symbol _start; defaulting to 0000807
/tmp/cc8FEzYi.o(.text+0x20): In function `main':                               
                                                                               
                                                     
: undefined reference to `__divsf3'                                            
                                                                               
                                                     
/tmp/cc8FEzYi.o(.text+0x40): In function `main':
: undefined reference to `__divdf3'                                            
                                                                               
        
collect2: ld returned 1 exit status

# arm-ep93xx-linux-gnu-gcc -v                                                  
                                                                                
Reading specs from
/home/larstiq/crosstool/arm-ep93xx-linux-gnu/gcc-3.4.0-glibc-2.3.2/bin/../lib/gcc/arm-ep93xx-linux-gnu/3.4.0/specs
                                                                               
Configured with: ../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
Thread model: single                                                           
                                                                               
                                                     
gcc version 3.4.0

-- 
           Summary: EP9312 gcc: undefined reference to __divdf3
           Product: gcc
           Version: 3.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: wouter at vidicode dot org
                CC: gcc-bugs at gcc dot gnu dot org
GCC target triplet: arm-elf


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16314

[Bug target/16314] EP9312 gcc: undefined reference to __divdf3

[rearnsha at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-07-01 13:57:00
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16314

[Bug target/16314] EP9312 gcc: undefined reference to __divdf3

[dank at kegel dot com]

------- Additional Comments From dank at kegel dot com  2004-08-30 14:12 -------
This happens for me when building any arm toolchain with softfloat with gcc-3.4.x.
http://gcc.gnu.org/ml/gcc-patches/2004-08/msg02436.html
seems to fix it for me.  
Note: the target tuple in this bug report was arm-elf, which is incorrect; 
it should be changed to arm-softfloat-linux-gnu or something like that.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16314

[Bug target/16314] EP9312 gcc: undefined reference to __divdf3

[dank at kegel dot com]

------- Additional Comments From dank at kegel dot com  2004-08-30 14:17 -------
This is kind of a fit-and-finish problem with gcc-3.4.2-pre.
Any chance the fix could be applied before release?

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mark at codesourcery dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16314

[Bug target/16314] EP9312 gcc: undefined reference to __divdf3

[mmitchel at gcc dot gnu dot org]

------- Additional Comments From mmitchel at gcc dot gnu dot org  2004-08-30 14:46 -------
If Richard Earnshaw approves this patch, we can put it in for GCC 3.4.2.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16314

[Bug target/16314] EP9312 gcc: undefined reference to __divdf3

[rearnsha at gcc dot gnu dot org]

------- Additional Comments From rearnsha at gcc dot gnu dot org  2004-08-31 09:14 -------
No, it won't work.  As things stand the ep9312 abi for linux expects the result
of the division to be returned in a Maverick register.  The soft-float routines
return a value in r0 or r0/r1.  So all it would do is punt the problem into a
hard-to-locate run-time one.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16314

[Bug target/16314] EP9312 gcc: undefined reference to __divdf3

[dank at kegel dot com]

------- Additional Comments From dank at kegel dot com  2004-08-31 13:14 -------
Then perhaps I should open a separate PR for the 
generic soft-float case...

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16314

[Bug target/16314] EP9312 gcc: undefined reference to __divdf3

[rearnsha at gcc dot gnu dot org]

------- Additional Comments From rearnsha at gcc dot gnu dot org  2004-08-31 13:16 -------
Subject: Re:  EP9312 gcc: undefined reference to __divdf3

On Tue, 2004-08-31 at 14:14, dank at kegel dot com wrote:
> ------- Additional Comments From dank at kegel dot com  2004-08-31 13:14 -------
> Then perhaps I should open a separate PR for the 
> generic soft-float case...

I think there already is one.  Daniel filed it.



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16314

[Bug target/16314] EP9312 gcc: undefined reference to __divdf3

[dank at kegel dot com]

------- Additional Comments From dank at kegel dot com  2004-08-31 15:17 -------
I can't find it.  If you run into it, can you paste in the PR number?
Otherwise I'll add a new one in a few days, and we can mark it dup later.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16314

[Bug target/16314] EP9312 gcc: undefined reference to __divdf3

[rearnsha at gcc dot gnu dot org]

------- Additional Comments From rearnsha at gcc dot gnu dot org  2004-09-01 10:44 -------
Subject: Re:  EP9312 gcc: undefined reference to __divdf3

On Tue, 2004-08-31 at 16:17, dank at kegel dot com wrote:
> ------- Additional Comments From dank at kegel dot com  2004-08-31 15:17 -------
> I can't find it.  If you run into it, can you paste in the PR number?

PR 14352.

R.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16314

Re: [Bug target/16314] EP9312 gcc: undefined reference to __divdf3

[Richard Earnshaw]

On Tue, 2004-08-31 at 16:17, dank at kegel dot com wrote:
> ------- Additional Comments From dank at kegel dot com  2004-08-31 15:17 -------
> I can't find it.  If you run into it, can you paste in the PR number?

PR 14352.

R.

[Bug target/16314] EP9312 gcc: undefined reference to __divdf3

[zhangyijin_2008 at 163 dot com]

------- Additional Comments From zhangyijin_2008 at 163 dot com  2004-11-23 06:04 -------
(In reply to comment #8)
> Subject: Re:  EP9312 gcc: undefined reference to __divdf3
> On Tue, 2004-08-31 at 16:17, dank at kegel dot com wrote:
> > ------- Additional Comments From dank at kegel dot com  2004-08-31 15:17 ---
----
> > I can't find it.  If you run into it, can you paste in the PR number?
> PR 14352.
> R.

I use this function and I test it can run ok. But I don`t know can it run ok 
always?
//double __divdf3(double a,double b ){ return a/b; }
	.file	"__divdf3.s"
	.global	__divdf3
	.text
	.align	2
	.global	__divdf3
	.type	__divdf3, %function
__divdf3:
	@ args = 0, pretend = 0, frame = 0
	@ frame_needed = 0, uses_anonymous_args = 0
	@ link register save eliminated.
	mov	ip, sp
	stmfd	sp!, {r4, fp, ip, lr, pc}
	sub	fp, ip, #4
	sub	sp, sp, #16
	str	r0, [fp, #-24]
	str	r1, [fp, #-20]
	str	r2, [fp, #-32]
	str	r3, [fp, #-28]
	ldfd	f1, [fp, #-24]
	ldfd	f0, [fp, #-32]
	dvfd	f0, f1, f0
	ldmfd	sp!, {r3, r4}
         cfmvdlr	mvd0, r3
	cfmvdhr	mvd0, r4
	sub	sp, fp, #16
	ldmfd	sp, {r4, fp, sp, pc}
        .end




-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16314

[Bug target/16314] EP9312 gcc: undefined reference to __divdf3

[zhangyijin_2008 at 163 dot com]

------- Additional Comments From zhangyijin_2008 at 163 dot com  2004-11-23 06:06 -------
(In reply to comment #8)
> Subject: Re:  EP9312 gcc: undefined reference to __divdf3
> On Tue, 2004-08-31 at 16:17, dank at kegel dot com wrote:
> > ------- Additional Comments From dank at kegel dot com  2004-08-31 15:17 ---
----
> > I can't find it.  If you run into it, can you paste in the PR number?
> PR 14352.
> R.

I use this function and I test it can run ok. But I don`t know can it run ok 
always?
//double __divdf3(double a,double b ){ return a/b; }
	.file	"__divdf3.s"
	.global	__divdf3
	.text
	.align	2
	.global	__divdf3
	.type	__divdf3, %function
__divdf3:
	@ args = 0, pretend = 0, frame = 0
	@ frame_needed = 0, uses_anonymous_args = 0
	@ link register save eliminated.
	mov	ip, sp
	stmfd	sp!, {r4, fp, ip, lr, pc}
	sub	fp, ip, #4
	sub	sp, sp, #16
	str	r0, [fp, #-24]
	str	r1, [fp, #-20]
	str	r2, [fp, #-32]
	str	r3, [fp, #-28]
	ldfd	f1, [fp, #-24]
	ldfd	f0, [fp, #-32]
	dvfd	f0, f1, f0
	ldmfd	sp!, {r3, r4}
         cfmvdlr	mvd0, r3
	cfmvdhr	mvd0, r4
	sub	sp, fp, #16
	ldmfd	sp, {r4, fp, sp, pc}
        .end




-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16314

[Bug target/16314] EP9312 gcc: undefined reference to __divdf3

[rearnsha at gcc dot gnu dot org]

------- Additional Comments From rearnsha at gcc dot gnu dot org  2004-11-23 11:03 -------
Subject: Re:  EP9312 gcc: undefined reference to __divdf3

On Tue, 2004-11-23 at 06:04, zhangyijin_2008 at 163 dot com wrote:
> I use this function and I test it can run ok. But I don`t know can it run ok 
> always?
> 	ldfd	f1, [fp, #-24]
> 	ldfd	f0, [fp, #-32]
> 	dvfd	f0, f1, f0

These are FPA instructions, the ep9312 does not have an FPA co-processor
and your linux kernel is emulating their behaviour in software.  That
won't work on an embedded system.

R.



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16314

[Bug target/16314] EP9312 gcc: undefined reference to __divdf3

[rearnsha at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16314

Richard Earnshaw <rearnsha at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |WONTFIX
   Target Milestone|---                         |4.8.0

--- Comment #14 from Richard Earnshaw <rearnsha at gcc dot gnu.org> 2012-07-10 09:10:18 UTC ---
Maverick support has now been dropped from GCC.

[Bug target/16314] EP9312 gcc: undefined reference to __divdf3

[nekkar at libero dot it]

------- Comment #13 from nekkar at libero dot it  2005-11-28 18:14 -------
Hi Richard

Could you explain us in details what would be in your opinion the best solution
to this problem?

Should we create a new maverick crunch target with specific division code or
what else?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16314

[Bug target/16314] EP9312 gcc: undefined reference to __divdf3

[rearnsha at gcc dot gnu dot org]

------- Comment #12 from rearnsha at gcc dot gnu dot org  2005-11-26 22:44 -------
*** Bug 25044 has been marked as a duplicate of this bug. ***


-- 

rearnsha at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |nekkar at libero dot it


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16314