[Pixman] Basic infrastructure for MIPS architecture and initial set of SRC routines.

[Siarhei Siamashka]

On Tue, Feb 21, 2012 at 4:59 PM, Nemanja Lukic <nlukic at mips.com> wrote:
>
> Per previous code review:
>
> Run time detection is still there (per Siarhei's comments), uses /proc/cpuinfo,
> but now properly detects DSPr2 extensions and 32 byte cache line size (both are
> true only for MIPS 74Kc cores).
>  - Currently only 74Kc core is available that supports DSPr2.
>  - In the future, when M14KE, 1074Kc cores (and others) become available we
>    can add those also to the search string.

One practical problem is that my MIPS router has the following line in
/proc/cpuinfo:
    cpu model		: MIPS 74K V4.0

Yes, unfortunately this router does not run a mainline kernel, but
searching for "MIPS 74K" instead of "MIPS 74Kc" could be used as a
workaround. As an additional bonus, it could also match "MIPS 74Kf".

> -mdspr2 compiler flag is automatically enabled for MIPS platforms. It can be
> disabled at configure time for chips that doesn't support it.

Apparently this is not enough to ensure a successful build:

$ ./autogen.sh && ./configure --disable-shared && make V=99

<snip>

checking whether to use MMX intrinsics... no
checking whether to use SSE2 intrinsics... no
checking whether to use VMX/Altivec intrinsics... no
checking whether to use ARM SIMD assembler... no
checking whether to use ARM NEON assembler... no
checking whether to use ARM IWMMXT intrinsics... no
checking whether to use MIPS DSPr2 assembler... yes
checking whether to use GNU-style inline assembler... yes

<snip>

libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I.. -g -O2 -Wall
-fno-strict-aliasing -fvisibility=hidden -MT pixman-utils.lo -MD -MP
-MF .deps/pixman-utils.Tpo -c pixman-utils.c -o pixman-utils.o
mv -f .deps/pixman-utils.Tpo .deps/pixman-utils.Plo
/bin/sh ../libtool  --tag=CC   --mode=compile gcc -DHAVE_CONFIG_H -I.
-I..     -mdspr2 -g -O2 -Wall -fno-strict-aliasing -fvisibility=hidden
-MT libpixman_mips_dspr2_la-pixman-mips-dspr2.lo -MD -MP -MF
.deps/libpixman_mips_dspr2_la-pixman-mips-dspr2.Tpo -c -o
libpixman_mips_dspr2_la-pixman-mips-dspr2.lo `test -f
'pixman-mips-dspr2.c' || echo './'`pixman-mips-dspr2.c
libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I.. -mdspr2 -g -O2 -Wall
-fno-strict-aliasing -fvisibility=hidden -MT
libpixman_mips_dspr2_la-pixman-mips-dspr2.lo -MD -MP -MF
.deps/libpixman_mips_dspr2_la-pixman-mips-dspr2.Tpo -c
pixman-mips-dspr2.c -o libpixman_mips_dspr2_la-pixman-mips-dspr2.o
Assembler messages:
Warning: mips1 ISA does not support DSP ASE
Warning: mips1 ISA does not support DSP R2 ASE
mv -f .deps/libpixman_mips_dspr2_la-pixman-mips-dspr2.Tpo
.deps/libpixman_mips_dspr2_la-pixman-mips-dspr2.Plo
/bin/sh ../libtool    --mode=compile gcc -DHAVE_CONFIG_H -I. -I..
-g -O2 -mdspr2 -MT pixman-mips-dspr2-asm.lo -MD -MP -MF
.deps/pixman-mips-dspr2-asm.Tpo -c -o pixman-mips-dspr2-asm.lo
pixman-mips-dspr2-asm.S
libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I.. -g -O2 -mdspr2 -MT
pixman-mips-dspr2-asm.lo -MD -MP -MF .deps/pixman-mips-dspr2-asm.Tpo
-c pixman-mips-dspr2-asm.S -o pixman-mips-dspr2-asm.o
Assembler messages:
Warning: mips1 ISA does not support DSP ASE
Warning: mips1 ISA does not support DSP R2 ASE
pixman-mips-dspr2-asm.S:70: Error: opcode not supported on this
processor: mips1 (mips1) `ext $9,$8,0x3,0x5'
pixman-mips-dspr2-asm.S:116: Error: opcode not supported on this
processor: mips1 (mips1) `ext $10,$8,0x2,0x3'
pixman-mips-dspr2-asm.S:146: Error: opcode not supported on this
processor: mips1 (mips1) `pref 0,32($5)'
pixman-mips-dspr2-asm.S:164: Error: opcode not supported on this
processor: mips1 (mips1) `pref 30,32($4)'
make[2]: *** [pixman-mips-dspr2-asm.lo] Error 1


This issue can be resolved by adding the following directives to the
assembly files, so that adding extra compiler flags is not even
needed:

.set arch=mips32r2
.set dspr2

And for pixman-mips-memcpy-asm.S just using ".set arch=mips32" is
enough (it does not use any DSP instructions).

-- 
Best regards,
Siarhei Siamashka