Re: [PATCH 3/3] tests/tcg/s390x: test signed vfmin/vfmax

[Richard Henderson]

On 7/12/22 18:02, Ilya Leoshkevich wrote:
> > This works, of course.  It could be simpler using EXECUTE, to store
> > just the one
> > instruction and not worry about an executable mapped page, but I
> > guess it doesn't matter.
>
> I thought about this too, but EX/EXRL operate only on the second byte,
> and I need to modify bytes 3-5 here.

I didn't mean modify the instruction via EX, but something like

  static char minmax[6] __attribute__((aligned(2)))
    = { xx, yy, zz, 0, 0, 0 };

  minmax[3] = m6 ...
  minmax[4] = ...
  minmax[5] = op;

  asm("vl %%v25,0(%1)\n"
      "vl %%v26,0(%2)\n"
      "ex 0,0(%3)\n"
      "vst %%v24,0(%0)"
      : : "a"(v1), "a"(v2), "a"(v3), "a"(minmax)
      : "memory", "v24", "v25", "v26);


r~