[PATCH 0/4] Refactor get_fpstatus_ptr() ready for AArch32 fp16

[Peter Maydell <peter.maydell@linaro.org>]

This patchset refactors the existing get_fpstatus_ptr() functions,
and fixes a bug where we weren't getting FZ16 right for AArch32
VCMLA, VCADD of fp16 types.

We currently have two versions of get_fpstatus_ptr(), which both take
an effectively boolean argument:
 * the one for A64 takes "bool is_f16" to distinguish fp16 from other ops
 * the one for A32/T32 takes "int neon" to distinguish Neon from other ops

This is confusing, and to implement ARMv8.2-FP16 the A32/T32 one will
need to make a four-way distinction between "non-Neon, FP16",
"non-Neon, single/double", "Neon, FP16" and "Neon, single/double".
The A64 version will then be a strict subset of the A32/T32 version.

The patchset creates a single fpstatus_ptr() function which takes
an enum selecting between the 4 possible fpstatus options.
It then adds the implementation of the "Neon standard FPST for f16".
Finally, we can then use to fix a bug in the VCMLA/VCADD fp16
handling where we were using FPST_STD rather than FPST_STD_F16.
(The difference is that the former will not honour FPSCR.FZ16.)

Based-on: 20200803111849.13368-1-peter.maydell@linaro.org
("[PATCH 0/7] target/arm: copro decode cleanup)
but only textually; there are no semantic dependencies to that series.

thanks
-- PMM

Peter Maydell (4):
  target/arm: Replace A64 get_fpstatus_ptr() with generic fpstatus_ptr()
  target/arm: Make A32/T32 use new fpstatus_ptr() API
  target/arm: Implement FPST_STD_F16 fpstatus
  target/arm: Use correct FPST for VCMLA, VCADD on fp16

 target/arm/cpu.h                |  9 +++-
 target/arm/translate-a64.h      |  1 -
 target/arm/translate.h          | 52 +++++++++++++++++++
 target/arm/cpu.c                |  3 ++
 target/arm/translate-a64.c      | 89 +++++++++++++--------------------
 target/arm/translate-neon.inc.c | 28 +++++------
 target/arm/translate-sve.c      | 34 ++++++-------
 target/arm/translate-vfp.inc.c  | 44 ++++++++--------
 target/arm/translate.c          | 13 -----
 target/arm/vfp_helper.c         |  5 ++
 10 files changed, 156 insertions(+), 122 deletions(-)

-- 
2.20.1