| Message ID | 20210723203344.968563-2-richard.henderson@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | target/arm: Add sve-default-vector-length cpu property | expand |
On Fri, 23 Jul 2021 at 21:36, Richard Henderson <richard.henderson@linaro.org> wrote: > > Currently, our only caller is sve_zcr_len_for_el, which has > already masked the length extracted from ZCR_ELx, so the > masking done here is a nop. But we will shortly have uses > from other locations, where the length will be unmasked. > > Saturate the length to ARM_MAX_VQ instead of truncating to > the low 4 bits. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- Reviewed-by: Peter Maydell <peter.maydell@linaro.org> thanks -- PMM
diff --git a/target/arm/helper.c b/target/arm/helper.c index 0c07ca9837..8c1d8dbce3 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -6461,7 +6461,9 @@ static uint32_t sve_zcr_get_valid_len(ARMCPU *cpu, uint32_t start_len) { uint32_t end_len; - end_len = start_len &= 0xf; + start_len = MIN(start_len, ARM_MAX_VQ - 1); + end_len = start_len; + if (!test_bit(start_len, cpu->sve_vq_map)) { end_len = find_last_bit(cpu->sve_vq_map, start_len); assert(end_len < start_len);
Currently, our only caller is sve_zcr_len_for_el, which has already masked the length extracted from ZCR_ELx, so the masking done here is a nop. But we will shortly have uses from other locations, where the length will be unmasked. Saturate the length to ARM_MAX_VQ instead of truncating to the low 4 bits. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- target/arm/helper.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)