Re: [PATCH 02/13] target/arm: Add isar_feature_any_fp16 and document naming/usage conventions

[Richard Henderson <richard.henderson@linaro.org>]

On 2/11/20 9:37 AM, Peter Maydell wrote:
> Our current usage of the isar_feature feature tests almost always
> uses an _aa32_ test when the code path is known to be AArch32
> specific and an _aa64_ test when the code path is known to be
> AArch64 specific. There is just one exception: in the vfp_set_fpscr
> helper we check aa64_fp16 to determine whether the FZ16 bit in
> the FP(S)CR exists, but this code is also used for AArch32.
> There are other places in future where we're likely to want
> a general "does this feature exist for either AArch32 or
> AArch64" check (typically where architecturally the feature exists
> for both CPU states if it exists at all, but the CPU might be
> AArch32-only or AArch64-only, and so only have one set of ID
> registers).
> 
> Introduce a new category of isar_feature_* functions:
> isar_feature_any_foo() should be tested when what we want to
> know is "does this feature exist for either AArch32 or AArch64",
> and always returns the logical OR of isar_feature_aa32_foo()
> and isar_feature_aa64_foo().
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  target/arm/cpu.h        | 19 ++++++++++++++++++-
>  target/arm/vfp_helper.c |  2 +-
>  2 files changed, 19 insertions(+), 2 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~