Re: [Qemu-devel] [PATCH V2 0/4] MIPS ASE DSP Support for Qemu

[Peter Maydell]

On 22 March 2012 13:36, Jia Liu <address@hidden> wrote:
> Jia Liu (4):
>  add MIPS DSP helpers define
>  add MIPS DSP helpers implement
>  add MIPS DSP translation
>  add MIPS DSP testcase

You can't split these changes into patches like this.
Every patch needs to be complete of itself, and in particular
it has to compile cleanly at each intermediate point, not just
after all patches are applied. If you apply just patch 1/4
then compilation fails:
  LINK  mips-softmmu/qemu-system-mips
translate.o: In function `mips_tcg_init':
/home/petmay01/linaro/qemu-from-laptop/qemu/target-mips/helper.h:301:
undefined reference to `helper_absqsph'
/home/petmay01/linaro/qemu-from-laptop/qemu/target-mips/helper.h:302:
undefined reference to `helper_absqsw'
/home/petmay01/linaro/qemu-from-laptop/qemu/target-mips/helper.h:303:
undefined reference to `helper_addqph'
[snipped long list of similar errors]

It would be better to break it up as patches each of
which adds support for a coherent bite-sized subset of
these instructions (so each individual patch includes
the helper function declaration, implementation and
translate.c changes for a smaller number of instructions).

You also need to test compilation on a 32 bit host, as that
is currently broken. For example:
/home/petmay01/linaro/qemu-from-laptop/qemu/target-mips/op_helper.c:
In function ‘mipsdsp_sat_add_i32’:
/home/petmay01/linaro/qemu-from-laptop/qemu/target-mips/op_helper.c:3565:
error: integer constant is too large for ‘long’ type
/home/petmay01/linaro/qemu-from-laptop/qemu/target-mips/op_helper.c:
In function ‘mipsdsp_mul_q31_q31’:
/home/petmay01/linaro/qemu-from-laptop/qemu/target-mips/op_helper.c:3874:
error: integer constant is too large for ‘long’ type
[and on for another long list of errors]

Most of these seem to be that you need the "ULL" suffix for
constants which are more than 32 bits wide.

-- PMM