[Xenomai-help] Error building userspace: "selected processor does not support `rsc r7, r7, #0'

[Xenomai-help] Error building userspace: "selected processor does not support `rsc r7, r7, #0'

[Jeremy Brown]

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Hello, all.  I'm trying to build Xenomai 2.5.3 userspace on a Beagleboard
(armel), but building timeconv.c is failing on an assembly error.  I would
appreciate any advice on how to solve it!
------
/bin/bash ../../../libtool --tag=CC   --mode=compile gcc -DHAVE_CONFIG_H -I.
-I../../.\
./src/include  -O2 -D_GNU_SOURCE -D_REENTRANT -Wall -pipe -march=armv7-a
-mfpu=vfp3 -m\
float-abi=softfp -D__XENO__ -D__IN_XENO__ -Wstrict-prototypes
-I../../../include    -M\
T libxenomai_la-timeconv.lo -MD -MP -MF .deps/libxenomai_la-timeconv.Tpo -c
-o libxeno\
mai_la-timeconv.lo `test -f 'timeconv.c' || echo './'`timeconv.c
libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I../../../src/include -O2
-D_GNU_SOURCE -D\
_REENTRANT -Wall -pipe -march=armv7-a -mfpu=vfp3 -mfloat-abi=softfp
-D__XENO__ -D__IN_\
XENO__ -Wstrict-prototypes -I../../../include -MT libxenomai_la-timeconv.lo
-MD -MP -M\
F .deps/libxenomai_la-timeconv.Tpo -c timeconv.c  -fPIC -DPIC -o
.libs/libxenomai_la-t\
imeconv.o
{standard input}: Assembler messages:
{standard input}:140: Error: selected processor does not support `rsc
r7,r7,#0'
{standard input}:159: Error: selected processor does not support `rsc
r1,r1,#0'
make: *** [libxenomai_la-timeconv.lo] Error 1
------

The OS is Ubuntu Lucid.  I'm using native tools, not cross-compilers,
directly on the Beagle.
$ uname -a
Linux beagleboard 2.6.32.11-l13 #1 PREEMPT Tue Apr 13 04:25:20 UTC 2010
armv7l GNU/Linux

Tools packages:
gcc 4:4.4.3-1ubuntu1
binutils 2.20.1-3ubuntu5

Xenomai configuration:
$ ./configure --prefix=/usr/local/xenomai --enable-arm-mach=omap3
--enable-arm-eabi --disable-arm-tsc

(I have tried this with and without the tsc disable.)

The running kernel is a vanilla linux 2.6.33 with the xenomai 2.5.3 patches
applied.

Thanks in advance for any and all help, suggestions, etc.

Jeremy

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Re: [Xenomai-help] Error building userspace: "selected processor does not support `rsc r7, r7, #0'

[Gilles Chanteperdrix]

Jeremy Brown wrote:
> {standard input}: Assembler messages:
> {standard input}:140: Error: selected processor does not support `rsc
> r7,r7,#0'
> {standard input}:159: Error: selected processor does not support `rsc
> r1,r1,#0'
> make: *** [libxenomai_la-timeconv.lo] Error 1

Ok. Could you try and compile the following piece of code with your
toolchain and show me the disassembly ?

long long foo(long long x)
{
        return -x;
}

-- 
					    Gilles.

Re: [Xenomai-help] Error building userspace: "selected processor does not support `rsc r7, r7, #0'

[Jeremy Brown]

On Mon, May 17, 2010 at 11:25 AM, Gilles Chanteperdrix
<gilles.chanteperdrix@xenomai.org> wrote:
> Jeremy Brown wrote:
> > {standard input}: Assembler messages:
> > {standard input}:140: Error: selected processor does not support `rsc
> > r7,r7,#0'
> > {standard input}:159: Error: selected processor does not support `rsc
> > r1,r1,#0'
> > make: *** [libxenomai_la-timeconv.lo] Error 1
>
> Ok. Could you try and compile the following piece of code with your
> toolchain and show me the disassembly ?
>
> long long foo(long long x)
> {
>        return -x;
> }
>
> --
>                                            Gilles.

Thanks for the quick reply!  Here's the complete contents of foo.s:

        .syntax unified
        .arch armv7-a
        .eabi_attribute 27, 3
        .fpu vfpv3-d16
        .eabi_attribute 20, 1
        .eabi_attribute 21, 1
        .eabi_attribute 23, 3
        .eabi_attribute 24, 1
        .eabi_attribute 25, 1
        .eabi_attribute 26, 2
        .eabi_attribute 30, 6
        .eabi_attribute 18, 4
        .thumb
        .file   "foo.c"
        .text
        .align  2
        .global foo
        .thumb
        .thumb_func
        .type   foo, %function
foo:
        @ args = 0, pretend = 0, frame = 8
        @ frame_needed = 1, uses_anonymous_args = 0
        @ link register save eliminated.
        push    {r7}
        sub     sp, sp, #12
        add     r7, sp, #0
        strd    r0, [r7]
        ldrd    r0, [r7]
        negs    r2, r0
        sbc     r3, r1, r1, lsl #1
        mov     r0, r2
        mov     r1, r3
        add     r7, r7, #12
        mov     sp, r7
        pop     {r7}
        bx      lr
        .size   foo, .-foo
        .ident  "GCC: (Ubuntu 4.4.3-4ubuntu5) 4.4.3"
        .section        .note.GNU-stack,"",%progbits

Re: [Xenomai-help] Error building userspace: "selected processor does not support `rsc r7, r7, #0'

[Gilles Chanteperdrix]

Jeremy Brown wrote:
> On Mon, May 17, 2010 at 11:25 AM, Gilles Chanteperdrix
> <gilles.chanteperdrix@xenomai.org> wrote:
>> Jeremy Brown wrote:
>>> {standard input}: Assembler messages:
>>> {standard input}:140: Error: selected processor does not support `rsc
>>> r7,r7,#0'
>>> {standard input}:159: Error: selected processor does not support `rsc
>>> r1,r1,#0'
>>> make: *** [libxenomai_la-timeconv.lo] Error 1
>> Ok. Could you try and compile the following piece of code with your
>> toolchain and show me the disassembly ?
>>
>> long long foo(long long x)
>> {
>>        return -x;
>> }
>>
>> --
>>                                            Gilles.
> 
> Thanks for the quick reply!  Here's the complete contents of foo.s:
> 
>         .syntax unified
>         .arch armv7-a
>         .eabi_attribute 27, 3
>         .fpu vfpv3-d16
>         .eabi_attribute 20, 1
>         .eabi_attribute 21, 1
>         .eabi_attribute 23, 3
>         .eabi_attribute 24, 1
>         .eabi_attribute 25, 1
>         .eabi_attribute 26, 2
>         .eabi_attribute 30, 6
>         .eabi_attribute 18, 4
>         .thumb
>         .file   "foo.c"
>         .text
>         .align  2
>         .global foo
>         .thumb
>         .thumb_func
>         .type   foo, %function
> foo:
>         @ args = 0, pretend = 0, frame = 8
>         @ frame_needed = 1, uses_anonymous_args = 0
>         @ link register save eliminated.
>         push    {r7}
>         sub     sp, sp, #12
>         add     r7, sp, #0
>         strd    r0, [r7]
>         ldrd    r0, [r7]
>         negs    r2, r0
>         sbc     r3, r1, r1, lsl #1
>         mov     r0, r2
>         mov     r1, r3
>         add     r7, r7, #12
>         mov     sp, r7
>         pop     {r7}
>         bx      lr
>         .size   foo, .-foo
>         .ident  "GCC: (Ubuntu 4.4.3-4ubuntu5) 4.4.3"
>         .section        .note.GNU-stack,"",%progbits
> 

Compile with -O2 please


-- 
					    Gilles.

Re: [Xenomai-help] Error building userspace: "selected processor does not support `rsc r7, r7, #0'

[Jeremy Brown]

On Mon, May 17, 2010 at 11:54 AM, Gilles Chanteperdrix
<gilles.chanteperdrix@xenomai.org> wrote:
> Jeremy Brown wrote:
>> On Mon, May 17, 2010 at 11:25 AM, Gilles Chanteperdrix
>> <gilles.chanteperdrix@xenomai.org> wrote:
>>> Jeremy Brown wrote:
>>>> {standard input}: Assembler messages:
>>>> {standard input}:140: Error: selected processor does not support `rsc
>>>> r7,r7,#0'
>>>> {standard input}:159: Error: selected processor does not support `rsc
>>>> r1,r1,#0'
>>>> make: *** [libxenomai_la-timeconv.lo] Error 1
>>> Ok. Could you try and compile the following piece of code with your
>>> toolchain and show me the disassembly ?
>>>
>>> long long foo(long long x)
>>> {
>>>        return -x;
>>> }
> Compile with -O2 please

        .syntax unified
        .arch armv7-a
        .eabi_attribute 27, 3
        .fpu vfpv3-d16
        .eabi_attribute 20, 1
        .eabi_attribute 21, 1
        .eabi_attribute 23, 3
        .eabi_attribute 24, 1
        .eabi_attribute 25, 1
        .eabi_attribute 26, 2
        .eabi_attribute 30, 6
        .eabi_attribute 18, 4
        .thumb
        .file   "foo.c"
        .text
        .align  2
        .global foo
        .thumb
        .thumb_func
        .type   foo, %function
foo:
        @ args = 0, pretend = 0, frame = 8
        @ frame_needed = 1, uses_anonymous_args = 0
        @ link register save eliminated.
        push    {r7}
        sub     sp, sp, #12
        add     r7, sp, #0
        strd    r0, [r7]
        ldrd    r0, [r7]
        negs    r2, r0
        sbc     r3, r1, r1, lsl #1
        mov     r0, r2
        mov     r1, r3
        add     r7, r7, #12
        mov     sp, r7
        pop     {r7}
        bx      lr
        .size   foo, .-foo
        .ident  "GCC: (Ubuntu 4.4.3-4ubuntu5) 4.4.3"
        .section        .note.GNU-stack,"",%progbits

Re: [Xenomai-help] Error building userspace: "selected processor does not support `rsc r7, r7, #0'

[Gilles Chanteperdrix]

Jeremy Brown wrote:
> On Mon, May 17, 2010 at 11:25 AM, Gilles Chanteperdrix
> <gilles.chanteperdrix@xenomai.org> wrote:
>> Jeremy Brown wrote:
>>> {standard input}: Assembler messages:
>>> {standard input}:140: Error: selected processor does not support `rsc
>>> r7,r7,#0'
>>> {standard input}:159: Error: selected processor does not support `rsc
>>> r1,r1,#0'
>>> make: *** [libxenomai_la-timeconv.lo] Error 1
>> Ok. Could you try and compile the following piece of code with your
>> toolchain and show me the disassembly ?
>>
>> long long foo(long long x)
>> {
>>        return -x;
>> }
>>
>> --
>>                                            Gilles.
> 
> Thanks for the quick reply!  Here's the complete contents of foo.s:
> 
>         .syntax unified

That is the key: I presume this means your compiler generates syntax
which works both with ARM and thumb2, and rsc does not exist with
thumb2. Note that from a performance point of view, this may not be a win.

So be it. Try the following patch:
diff --git a/include/asm-arm/arith.h b/include/asm-arm/arith.h
index e86975c..72c0ab7 100644
--- a/include/asm-arm/arith.h
+++ b/include/asm-arm/arith.h
@@ -103,13 +103,13 @@ rthal_arm_nodiv_llimd(const long long op,
 	__asm__ ("movs %[s], %[oph], lsr #30\n\t"
 		 "beq 1f\n\t"
 		 "rsbs  %[opl], %[opl], #0\n\t"
-		 "rsc  %[oph], %[oph], #0\n"
+		 "sbc  %[oph], %[oph], %[oph], lsl #1\n"
 		 "1:\t"
 		 rthal_arm_nodiv_ullimd_str
 		 "teq %[s], #0\n\t"
 		 "beq 2f\n\t"
 		 "rsbs  %[rm], %[rm], #0\n\t"
-		 "rsc  %[rh], %[rh], #0\n"
+		 "sbc  %[rh], %[rh], %[rh], lsl #1\n"
 		 "2:\t"
 		 : [rl]"=r"(rl), [rm]"=r"(rm), [rh]"=r"(rh),
 		   [tl]"=r"(tl), [th]"=r"(th), [s]"=r"(s)



-- 
					    Gilles.

Re: [Xenomai-help] Error building userspace: "selected processor does not support `rsc r7, r7, #0'

[Jeremy Brown]

On Mon, May 17, 2010 at 12:01 PM, Gilles Chanteperdrix
<gilles.chanteperdrix@xenomai.org> wrote:
> Jeremy Brown wrote:
>> On Mon, May 17, 2010 at 11:25 AM, Gilles Chanteperdrix
>> <gilles.chanteperdrix@xenomai.org> wrote:
>>> Jeremy Brown wrote:
>>>> {standard input}: Assembler messages:
>>>> {standard input}:140: Error: selected processor does not support `rsc
>>>> r7,r7,#0'
>>>> {standard input}:159: Error: selected processor does not support `rsc
>>>> r1,r1,#0'
>>>> make: *** [libxenomai_la-timeconv.lo] Error 1
>>> Ok. Could you try and compile the following piece of code with your
>>> toolchain and show me the disassembly ?
>>>
>>> long long foo(long long x)
>>> {
>>>        return -x;
>>> }
>>>
>>> --
>>>                                            Gilles.
>>
>> Thanks for the quick reply!  Here's the complete contents of foo.s:
>>
>>         .syntax unified
>
> That is the key: I presume this means your compiler generates syntax
> which works both with ARM and thumb2, and rsc does not exist with
> thumb2. Note that from a performance point of view, this may not be a win.
>
> So be it. Try the following patch:

Thank you.  That solved this particular problem.   (Something in
cond.c is now causing a gcc internal compiler error, so I think this
toolchain is generally suspect, but that's not even vaguely a Xenomai
problem now.)

Jeremy

> diff --git a/include/asm-arm/arith.h b/include/asm-arm/arith.h
> index e86975c..72c0ab7 100644
> --- a/include/asm-arm/arith.h
> +++ b/include/asm-arm/arith.h
> @@ -103,13 +103,13 @@ rthal_arm_nodiv_llimd(const long long op,
>        __asm__ ("movs %[s], %[oph], lsr #30\n\t"
>                 "beq 1f\n\t"
>                 "rsbs  %[opl], %[opl], #0\n\t"
> -                "rsc  %[oph], %[oph], #0\n"
> +                "sbc  %[oph], %[oph], %[oph], lsl #1\n"
>                 "1:\t"
>                 rthal_arm_nodiv_ullimd_str
>                 "teq %[s], #0\n\t"
>                 "beq 2f\n\t"
>                 "rsbs  %[rm], %[rm], #0\n\t"
> -                "rsc  %[rh], %[rh], #0\n"
> +                "sbc  %[rh], %[rh], %[rh], lsl #1\n"
>                 "2:\t"
>                 : [rl]"=r"(rl), [rm]"=r"(rm), [rh]"=r"(rh),
>                   [tl]"=r"(tl), [th]"=r"(th), [s]"=r"(s)

Re: [Xenomai-help] Error building userspace: "selected processor does not support `rsc r7, r7, #0'

[Jeremy Brown]

On Mon, May 17, 2010 at 12:24 PM, Jeremy Brown <jhbrown@domain.hid> wrote:
> Something in cond.c is now causing a gcc internal compiler error, so I think this toolchain is generally suspect, but that's not even vaguely a Xenomai problem now.)

Hm.  Turning off optimization, the ICE goes away and I get
"cond.c:30:  error:  r7 cannot be used in asm here."  This is at the
expansion of XENOMAI_SKINCALL1.  Is this more thumb-related headaches?
  Am I going to be better off just finding or building a toolchain
that's not trying to use the unified instructions?

Thanks again,
Jeremy

Re: [Xenomai-help] Error building userspace: "selected processor does not support `rsc r7, r7, #0'

[Jeremy Brown]

On Mon, May 17, 2010 at 12:01 PM, Gilles Chanteperdrix
<gilles.chanteperdrix@xenomai.org> wrote:
> Jeremy Brown wrote:
>> On Mon, May 17, 2010 at 11:25 AM, Gilles Chanteperdrix
>> <gilles.chanteperdrix@xenomai.org> wrote:
>>> Jeremy Brown wrote:
>>>> {standard input}: Assembler messages:
>>>> {standard input}:140: Error: selected processor does not support `rsc
>>>> r7,r7,#0'
>>>> {standard input}:159: Error: selected processor does not support `rsc
>>>> r1,r1,#0'
>>>> make: *** [libxenomai_la-timeconv.lo] Error 1
>>> Ok. Could you try and compile the following piece of code with your
>>> toolchain and show me the disassembly ?
>>>
>>> long long foo(long long x)
>>> {
>>>        return -x;
>>> }
>>>
>>> --
>>>                                            Gilles.
>>
>> Thanks for the quick reply!  Here's the complete contents of foo.s:
>>
>>         .syntax unified
>
> That is the key: I presume this means your compiler generates syntax
> which works both with ARM and thumb2, and rsc does not exist with
> thumb2. Note that from a performance point of view, this may not be a win.

Ah, success --- based on your note, a colleague of mine determined
that arranging to pass gcc the (undocumented) "-marm" flag enables the
compiler to build the unpatched Xenomai 2.5.3 sources from beginning
to end.  For posterity, I recompiled your example code with -O2 -marm,
and appended it below.

Thank you for all of your help!

Jeremy

        .arch armv7-a
        .eabi_attribute 27, 3
        .fpu vfpv3-d16
        .eabi_attribute 20, 1
        .eabi_attribute 21, 1
        .eabi_attribute 23, 3
        .eabi_attribute 24, 1
        .eabi_attribute 25, 1
        .eabi_attribute 26, 2
        .eabi_attribute 30, 2
        .eabi_attribute 18, 4
        .file   "foo.c"
        .text
        .align  2
        .global foo
        .type   foo, %function
foo:
        @ args = 0, pretend = 0, frame = 0
        @ frame_needed = 0, uses_anonymous_args = 0
        @ link register save eliminated.
        rsbs    r2, r0, #0
        rsc     r3, r1, #0
        mov     r1, r3
        mov     r0, r2
        bx      lr
        .size   foo, .-foo
        .ident  "GCC: (Ubuntu 4.4.3-4ubuntu5) 4.4.3"
        .section        .note.GNU-stack,"",%progbits

Re: [Xenomai-help] Error building userspace: "selected processor does not support `rsc r7, r7, #0'

[Gilles Chanteperdrix]

Jeremy Brown wrote:
>>>         .syntax unified
>> That is the key: I presume this means your compiler generates syntax
>> which works both with ARM and thumb2, and rsc does not exist with
>> thumb2. Note that from a performance point of view, this may not be a win.
> 
> Ah, success --- based on your note, a colleague of mine determined
> that arranging to pass gcc the (undocumented) "-marm" flag enables the
> compiler to build the unpatched Xenomai 2.5.3 sources from beginning
> to end.  For posterity, I recompiled your example code with -O2 -marm,
> and appended it below.

Ok. Does it solve the ICE too?

-- 
					    Gilles.

Re: [Xenomai-help] Error building userspace: "selected processor does not support `rsc r7, r7, #0'

[Jeremy Brown]

On Mon, May 17, 2010 at 4:57 PM, Gilles Chanteperdrix
<gilles.chanteperdrix@xenomai.org> wrote:
> Jeremy Brown wrote:
>>>>         .syntax unified
>>> That is the key: I presume this means your compiler generates syntax
>>> which works both with ARM and thumb2, and rsc does not exist with
>>> thumb2. Note that from a performance point of view, this may not be a win.
>>
>> Ah, success --- based on your note, a colleague of mine determined
>> that arranging to pass gcc the (undocumented) "-marm" flag enables the
>> compiler to build the unpatched Xenomai 2.5.3 sources from beginning
>> to end.  For posterity, I recompiled your example code with -O2 -marm,
>> and appended it below.
>
> Ok. Does it solve the ICE too?

Yes, it does, thanks.  Everything compiles and xeno-test runs to completion.

Jeremy