On 06/25/2018 09:13 AM, Peter Maydell wrote:
> On 21 June 2018 at 02:53, Richard Henderson
> <richard.hender...@linaro.org> wrote:
>> Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
>> ---
>> target/arm/helper-sve.h | 41 +++++++++++++++++++++
>> target/arm/sve_helper.c | 62 ++++++++++++++++++++++++++++++++
>> target/arm/translate-sve.c | 74 ++++++++++++++++++++++++++++++++++++++
>> target/arm/sve.decode | 39 ++++++++++++++++++++
>> 4 files changed, 216 insertions(+)
>> +/* Stores with a vector index. */
>> +
>> +#define DO_ST1_ZPZ_S(NAME, TYPEI, FN) \
>> +void HELPER(NAME)(CPUARMState *env, void *vd, void *vg, void *vm, \
>> + target_ulong base, uint32_t desc) \
>> +{ \
>> + intptr_t i, oprsz = simd_oprsz(desc) / 8; \
>> + unsigned scale = simd_data(desc); \
>> + uintptr_t ra = GETPC(); \
>> + uint32_t *d = vd; TYPEI *m = vm; uint8_t *pg = vg; \
>> + for (i = 0; i < oprsz; i++) { \
>> + uint8_t pp = pg[H1(i)]; \
>> + if (pp & 0x01) { \
>> + target_ulong off = (target_ulong)m[H4(i * 2)] << scale; \
>> + FN(env, base + off, d[H4(i * 2)], ra); \
>> + } \
>> + if (pp & 0x10) { \
>> + target_ulong off = (target_ulong)m[H4(i * 2 + 1)] << scale; \
>> + FN(env, base + off, d[H4(i * 2 + 1)], ra); \
>> + } \
>> + } \
>> +}
>
> Why do we do two operations per loop here? Generally
> we seem to do one operation per loop elsewhere.
I'm not sure why I wrote this one in this way.
There doesn't seem to be a good reason.
>> +static bool trans_ST1_zprz(DisasContext *s, arg_ST1_zprz *a, uint32_t insn)
>> +{
>> + /* Indexed by [xs][msz]. */
>> + static gen_helper_gvec_mem_scatter * const fn32[2][3] = {
>> + { gen_helper_sve_stbs_zsu,
>> + gen_helper_sve_sths_zsu,
>> + gen_helper_sve_stss_zsu, },
>> + { gen_helper_sve_stbs_zss,
>> + gen_helper_sve_sths_zss,
>> + gen_helper_sve_stss_zss, },
>> + };
>> + static gen_helper_gvec_mem_scatter * const fn64[3][4] = {
>
> In the pseudocode xs is either 0 (zero-extend offset) or
> 1 (sign-extend offset), but here it can also be 2. A
> comment noting that we've overloaded it to also indicate
> whether we're dealing with a 32-bit or 64-bit offset might
> help (at least I think that's what we're doing).
Yes, xs=2 is overloaded to mean 64-bit offset.
I'll add comments.
r~
