[Bug libffi/40242] New: unsupported asm instructions in libffi/src/arm/sysv.S

[Bug libffi/40242] New: unsupported asm instructions in libffi/src/arm/sysv.S

[mkl at pengutronix dot de]

Hello,

during cross compilation of gcc, the libffi build for the target breaks with
this error message:

libtool: compile:  /home/frogger/pengutronix/toolchain/libffi/build/./gcc/xgcc
-B/home/frogger/pengutronix/toolchain/libffi/build/./gcc/
-B/usr/local/arm-1136jfs-linux-gnueabi/bin/
-B/usr/local/arm-1136jfs-linux-gnueabi/lib/ -isystem
/usr/local/arm-1136jfs-linux-gnueabi/include -isystem
/usr/local/arm-1136jfs-linux-gnueabi/sys-include -I.
-I../../../gcc-4.4.0/libffi/include -Iinclude -I../../../gcc-4.4.0/libffi/src
-g -O2 -c ../../../gcc-4.4.0/libffi/src/arm/sysv.S  -fPIC -DPIC -o
src/arm/.libs/sysv.o
../../../gcc-4.4.0/libffi/src/arm/sysv.S: Assembler messages:
../../../gcc-4.4.0/libffi/src/arm/sysv.S:202: Error: selected processor does
not support `stfeqs f0,[r2]'
../../../gcc-4.4.0/libffi/src/arm/sysv.S:207: Error: selected processor does
not support `stfeqd f0,[r2]'
../../../gcc-4.4.0/libffi/src/arm/sysv.S:282: Error: selected processor does
not support `ldfs f0,[sp]'
../../../gcc-4.4.0/libffi/src/arm/sysv.S:285: Error: selected processor does
not support `ldfd f0,[sp]'
../../../gcc-4.4.0/libffi/src/arm/sysv.S:288: Error: selected processor does
not support `ldfd f0,[sp]'

the offending code is:

#ifndef __SOFTFP__
        beq     LSYM(Lepilogue)

@ return FLOAT
        cmp     r3, #FFI_TYPE_FLOAT
        stfeqs  f0, [r2]
        beq     LSYM(Lepilogue)

@ return DOUBLE or LONGDOUBLE
        cmp     r3, #FFI_TYPE_DOUBLE
        stfeqd  f0, [r2]
#endif


gcc is configured this way:

../gcc-4.4.0/configure --enable-languages=c,c++,java
--target=arm-1136jfs-linux-gnueabi
--with-mpfr=/home/frogger/pengutronix/toolchain/OSELAS.Toolchain-trunk/platform-arm-v4t-linux-gnueabi-gcc-4.4.0-glibc-2.9-binutils-2.19.1-kernel-2.6.29-sanitized/sysroot-host
--with-gmp=/home/frogger/pengutronix/toolchain/OSELAS.Toolchain-trunk/platform-arm-v4t-linux-gnueabi-gcc-4.4.0-glibc-2.9-binutils-2.19.1-kernel-2.6.29-sanitized/sysroot-host
--with-float=softfp --with-fpu=vfp  --with-cpu=arm1136jf-s
--with-sysroot=/opt/OSELAS.Toolchain-1.99.3/arm-1136jfs-linux-gnueabi/gcc-4.3.2-glibc-2.8-binutils-2.19-kernel-2.6.27-sanitized/sysroot-arm-1136jfs-linux-gnueabi

I.e. as an arm-eabi target, --with-fpu=vfp and --with-float=softfp. Which means
floats are passed in integer registers, but in function the compiler generates
floating point instructions, the preprocessor doesn't define a "__SOFTFP__"
symbol.

If configuring the compiler with "--with-float=soft" it will pass floats in
integer registers and it will generate softfloat emulation code. In this case
the preprocessor defines "__SOFTFP__".

In both variants the function calling convention is the same, but in one case
we have the __SOFTFP__ symbol in the other not.

libffi changes it's behaviour depending on this symbol, which is IMHO not
correct.

I've tested some combinations, this is the summary of
(echo | arm-v4t-linux-gnueabi-cpp -dM -mfloat-abi=XXX -mfpu=YYY| egrep -i
'vfp|fp|soft|hard|float'):

-mfloat-abi=soft   -mfpu=vfp    __SOFTFP__ __VFP_FP__
-mfloat-abi=softfp -mfpu=vfp               __VFP_FP__
-mfloat-abi=hard   -mfpu=vfp               __VFP_FP__ (sorry, unimplemented)

-mfloat-abi=soft   -mfpu=fpa    __SOFTFP__
-mfloat-abi=softfp -mfpu=fpa
-mfloat-abi=hard   -mfpu=fpa

I'm not sure which of these combinations makes sense, or are actually used, the
3rd one seems not to be implemented, though. We at pengutronix use usually 1.
and 2. In some weird projects 4. and 6. but not with the current gcc.

This table shows that it's not possible to distinguish between the "hard" and
"softfp" case, a diff off the preprocessor's output shows no difference in the
symbols tough. On the upside the vfp-hard case seems not to be implemented.

So the question is which is the correct symbol for libffi?

cheers, Marc


-- 
           Summary: unsupported asm instructions in libffi/src/arm/sysv.S
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libffi
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: mkl at pengutronix dot de
 GCC build triplet: x86_64-unknown-linux-gnu
  GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: arm-1136jfs-linux-gnueabi


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40242

[Bug libffi/40242] unsupported asm instructions in libffi/src/arm/sysv.S

[ramana at gcc dot gnu dot org]

------- Comment #1 from ramana at gcc dot gnu dot org  2009-05-27 09:50 -------
(In reply to comment #0)
> Hello,
> 
> during cross compilation of gcc, the libffi build for the target breaks with
> this error message:
> 
> libtool: compile:  /home/frogger/pengutronix/toolchain/libffi/build/./gcc/xgcc
> -B/home/frogger/pengutronix/toolchain/libffi/build/./gcc/
> -B/usr/local/arm-1136jfs-linux-gnueabi/bin/
> -B/usr/local/arm-1136jfs-linux-gnueabi/lib/ -isystem
> /usr/local/arm-1136jfs-linux-gnueabi/include -isystem
> /usr/local/arm-1136jfs-linux-gnueabi/sys-include -I.
> -I../../../gcc-4.4.0/libffi/include -Iinclude -I../../../gcc-4.4.0/libffi/src
> -g -O2 -c ../../../gcc-4.4.0/libffi/src/arm/sysv.S  -fPIC -DPIC -o
> src/arm/.libs/sysv.o
> ../../../gcc-4.4.0/libffi/src/arm/sysv.S: Assembler messages:
> ../../../gcc-4.4.0/libffi/src/arm/sysv.S:202: Error: selected processor does
> not support `stfeqs f0,[r2]'
> ../../../gcc-4.4.0/libffi/src/arm/sysv.S:207: Error: selected processor does
> not support `stfeqd f0,[r2]'
> ../../../gcc-4.4.0/libffi/src/arm/sysv.S:282: Error: selected processor does
> not support `ldfs f0,[sp]'
> ../../../gcc-4.4.0/libffi/src/arm/sysv.S:285: Error: selected processor does
> not support `ldfd f0,[sp]'
> ../../../gcc-4.4.0/libffi/src/arm/sysv.S:288: Error: selected processor does
> not support `ldfd f0,[sp]'
> 
> the offending code is:
> 
> #ifndef __SOFTFP__
>         beq     LSYM(Lepilogue)
> 
> @ return FLOAT
>         cmp     r3, #FFI_TYPE_FLOAT
>         stfeqs  f0, [r2]
>         beq     LSYM(Lepilogue)
> 
> @ return DOUBLE or LONGDOUBLE
>         cmp     r3, #FFI_TYPE_DOUBLE
>         stfeqd  f0, [r2]
> #endif
> 
> 
> gcc is configured this way:
> 
> ../gcc-4.4.0/configure --enable-languages=c,c++,java
> --target=arm-1136jfs-linux-gnueabi
> --with-mpfr=/home/frogger/pengutronix/toolchain/OSELAS.Toolchain-trunk/platform-arm-v4t-linux-gnueabi-gcc-4.4.0-glibc-2.9-binutils-2.19.1-kernel-2.6.29-sanitized/sysroot-host
> --with-gmp=/home/frogger/pengutronix/toolchain/OSELAS.Toolchain-trunk/platform-arm-v4t-linux-gnueabi-gcc-4.4.0-glibc-2.9-binutils-2.19.1-kernel-2.6.29-sanitized/sysroot-host
> --with-float=softfp --with-fpu=vfp  --with-cpu=arm1136jf-s
> --with-sysroot=/opt/OSELAS.Toolchain-1.99.3/arm-1136jfs-linux-gnueabi/gcc-4.3.2-glibc-2.8-binutils-2.19-kernel-2.6.27-sanitized/sysroot-arm-1136jfs-linux-gnueabi
> 
> I.e. as an arm-eabi target, --with-fpu=vfp and --with-float=softfp. Which means
> floats are passed in integer registers, but in function the compiler generates
> floating point instructions, the preprocessor doesn't define a "__SOFTFP__"
> symbol.
> 
> If configuring the compiler with "--with-float=soft" it will pass floats in
> integer registers and it will generate softfloat emulation code. In this case
> the preprocessor defines "__SOFTFP__".
> 
> In both variants the function calling convention is the same, but in one case
> we have the __SOFTFP__ symbol in the other not.
> 
> libffi changes it's behaviour depending on this symbol, which is IMHO not
> correct.
> 
> I've tested some combinations, this is the summary of
> (echo | arm-v4t-linux-gnueabi-cpp -dM -mfloat-abi=XXX -mfpu=YYY| egrep -i
> 'vfp|fp|soft|hard|float'):
> 
> -mfloat-abi=soft   -mfpu=vfp    __SOFTFP__ __VFP_FP__
> -mfloat-abi=softfp -mfpu=vfp               __VFP_FP__
> -mfloat-abi=hard   -mfpu=vfp               __VFP_FP__ (sorry, unimplemented)
> 
> -mfloat-abi=soft   -mfpu=fpa    __SOFTFP__
> -mfloat-abi=softfp -mfpu=fpa
> -mfloat-abi=hard   -mfpu=fpa
> 
> I'm not sure which of these combinations makes sense, or are actually used, the
> 3rd one seems not to be implemented, though. We at pengutronix use usually 1.
> and 2. In some weird projects 4. and 6. but not with the current gcc.

Using mfpu=fpa in eabi configurations is wrong. Trunk is now patched to no
longer allow this.


> 
> This table shows that it's not possible to distinguish between the "hard" and
> "softfp" case, a diff off the preprocessor's output shows no difference in the
> symbols tough. On the upside the vfp-hard case seems not to be implemented.

The difference between vfp-hard and softfp is whether we use the VFP registers
for passing parameters or not. Currently softfp is the only one implemented in
trunk and all release branches though an implementation is under way in an
architecture specific branch viz. ARM/hardvfp_4_4_branch. 

> 
> So the question is which is the correct symbol for libffi?

If there is code in here that tries to return values in floating point
registers if SOFTFP is not defined then it is clearly wrong and we need another
macro to distinguish the case.

I am not sure if there exists a symbol for this and I am not sure about the
code  in this. CC'ing Andrew Haley about this one. 

> 
> cheers, Marc
> 


-- 

ramana at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |aph at redhat dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40242

[Bug libffi/40242] unsupported asm instructions in libffi/src/arm/sysv.S

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2009-05-29 02:53 -------
http://www.nabble.com/Re:-libFFI-arm-compilation-fails-with-assembly-td20346235.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40242

[Bug libffi/40242] unsupported asm instructions in libffi/src/arm/sysv.S

[mkl at pengutronix dot de]

------- Comment #3 from mkl at pengutronix dot de  2009-05-29 08:22 -------
Hello Andrew,

(In reply to comment #2)
> http://www.nabble.com/Re:-libFFI-arm-compilation-fails-with-assembly-td20346235.html

BTW: I'm not compiling libffi stand alone, here. I'm building the gcc with java
enabled.

IMHO using "-mfloat-abi=soft" when preprocessing sysv.S can be considered a
workaround not a fix.

It makes only sense if the compiler passes (by default) floats in the integer
registers (-mfloat-abi=soft and -mfloat-abi=softfp), and breaks if passing in
the float registers (-mfloat-abi=hard).

With the work done in ARM/hardvfp_4_4_branch the -mfloat-abi=hard case is more
relevant then ever.

This means we cannot use "-mfloat-abi=soft" unconditionally, which boils down
(again) to the question: how can we distinguish between the
float-passed-in-int-regs and float-passed-in-float-regs case. Ideally this
should work if building libffi as part of gcc and if building libffi
standalone.

cheers, Marc


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40242

[Bug libffi/40242] unsupported asm instructions in libffi/src/arm/sysv.S

[ramana at gcc dot gnu dot org]

------- Comment #4 from ramana at gcc dot gnu dot org  2009-06-12 13:13 -------

There was a merge of some work from libffi recently and IIRC I saw some commits
go into the same file. Can you check if that fixes your problem ?

Ramana


> 
> This means we cannot use "-mfloat-abi=soft" unconditionally, which boils down
> (again) to the question: how can we distinguish between the
> float-passed-in-int-regs and float-passed-in-float-regs case. Ideally this
> should work if building libffi as part of gcc and if building libffi
> standalone.


> 
> cheers, Marc
> 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40242

[Bug libffi/40242] unsupported asm instructions in libffi/src/arm/sysv.S

[ramana at gcc dot gnu dot org]

-- 

ramana at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40242

[Bug libffi/40242] unsupported asm instructions in libffi/src/arm/sysv.S

[ramana at gcc dot gnu dot org]

------- Comment #5 from ramana at gcc dot gnu dot org  2009-08-03 08:31 -------
Confirmed with Trunk as of 150308


-- 

ramana at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|0000-00-00 00:00:00         |2009-08-03 08:31:56
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40242

[Bug libffi/40242] unsupported asm instructions in libffi/src/arm/sysv.S

[ramana at gcc dot gnu dot org]

------- Comment #6 from ramana at gcc dot gnu dot org  2009-08-03 08:33 -------
(In reply to comment #5)
> Confirmed with Trunk as of 150308
> 

With the following options. 

 /home/ramrad01/sources/trunk/configure --with-cpu=cortex-a8
--with-float=softfp --with-fpu=neon


-- 

ramana at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|2009-08-03 08:31:56         |2009-08-03 08:33:28
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40242

[Bug libffi/40242] unsupported asm instructions in libffi/src/arm/sysv.S

[ramana at gcc dot gnu dot org]

------- Comment #7 from ramana at gcc dot gnu dot org  2009-09-23 12:41 -------
*** Bug 41443 has been marked as a duplicate of this bug. ***


-- 

ramana at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |doko at ubuntu dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40242

[Bug libffi/40242] unsupported asm instructions in libffi/src/arm/sysv.S

[doko at gcc dot gnu dot org]

------- Comment #8 from doko at gcc dot gnu dot org  2009-09-23 14:50 -------
Subject: Bug 40242

Author: doko
Date: Wed Sep 23 14:50:35 2009
New Revision: 152075

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=152075
Log:
2009-09-23  Matthias Klose  <doko@ubuntu.com>

        PR libffi/40242, PR libffi/41443
        * src/arm/sysv.S (__ARM_ARCH__): Define for processors
        __ARM_ARCH_6T2__, __ARM_ARCH_6M__, __ARM_ARCH_7__,
        __ARM_ARCH_7A__, __ARM_ARCH_7R__, __ARM_ARCH_7M__.
        Change the conditionals to __SOFTFP__ || __ARM_EABI__
        for -mfloat-abi=softfp to work.

Modified:
    trunk/libffi/ChangeLog
    trunk/libffi/src/arm/sysv.S


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40242

[Bug libffi/40242] unsupported asm instructions in libffi/src/arm/sysv.S

[doko at gcc dot gnu dot org]

------- Comment #9 from doko at gcc dot gnu dot org  2009-09-23 15:08 -------
Subject: Bug 40242

Author: doko
Date: Wed Sep 23 15:08:02 2009
New Revision: 152078

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=152078
Log:
2009-09-23  Matthias Klose  <doko@ubuntu.com>

        PR libffi/40242, PR libffi/41443
        * src/arm/sysv.S (__ARM_ARCH__): Define for processors
        __ARM_ARCH_6T2__, __ARM_ARCH_6M__, __ARM_ARCH_7__,
        __ARM_ARCH_7A__, __ARM_ARCH_7R__, __ARM_ARCH_7M__.
        Change the conditionals to __SOFTFP__ || __ARM_EABI__
        for -mfloat-abi=softfp to work.

Modified:
    branches/gcc-4_4-branch/libffi/ChangeLog
    branches/gcc-4_4-branch/libffi/src/arm/sysv.S


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40242

[Bug libffi/40242] unsupported asm instructions in libffi/src/arm/sysv.S

[doko at gcc dot gnu dot org]

------- Comment #10 from doko at gcc dot gnu dot org  2009-09-23 15:11 -------
Subject: Bug 40242

Author: doko
Date: Wed Sep 23 15:11:17 2009
New Revision: 152079

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=152079
Log:
2009-09-23  Matthias Klose  <doko@ubuntu.com>

        PR libffi/40242, PR libffi/41443
        * src/arm/sysv.S (__ARM_ARCH__): Define for processors
        __ARM_ARCH_6T2__, __ARM_ARCH_6M__, __ARM_ARCH_7__,
        __ARM_ARCH_7A__, __ARM_ARCH_7R__, __ARM_ARCH_7M__.
        Change the conditionals to __SOFTFP__ || __ARM_EABI__
        for -mfloat-abi=softfp to work.

Modified:
    branches/gcc-4_3-branch/libffi/ChangeLog
    branches/gcc-4_3-branch/libffi/src/arm/sysv.S


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40242

[Bug libffi/40242] unsupported asm instructions in libffi/src/arm/sysv.S

[dwitte at mozilla dot com]

------- Comment #11 from dwitte at mozilla dot com  2009-11-24 21:12 -------
Anthony, any chance you could pick this fix up for libffi 3.0.9?


-- 

dwitte at mozilla dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |green at redhat dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40242

[Bug libffi/40242] unsupported asm instructions in libffi/src/arm/sysv.S

[ramana at gcc dot gnu dot org]

------- Comment #12 from ramana at gcc dot gnu dot org  2009-12-10 15:18 -------
This is now fixed in trunk and all release branches. 


-- 

ramana at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.3.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40242