diff options
| author | Richard Henderson | 2022-06-08 20:38:57 +0200 |
|---|---|---|
| committer | Peter Maydell | 2022-06-08 20:38:57 +0200 |
| commit | 886902ece71b5e795fea3e052a32f047d2f8fe33 (patch) | |
| tree | 4d5e81ad570d44e4b574c4b3f272bb8eb07a829c /target/arm/helper.c | |
| parent | target/arm: Merge aarch64_sve_zcr_get_valid_len into caller (diff) | |
| download | qemu-886902ece71b5e795fea3e052a32f047d2f8fe33.tar.gz qemu-886902ece71b5e795fea3e052a32f047d2f8fe33.tar.xz qemu-886902ece71b5e795fea3e052a32f047d2f8fe33.zip | |
target/arm: Use uint32_t instead of bitmap for sve vq's
The bitmap need only hold 15 bits; bitmap is over-complicated.
We can simplify operations quite a bit with plain logical ops.
The introduction of SVE_VQ_POW2_MAP eliminates the need for
looping in order to search for powers of two. Simply perform
the logical ops and use count leading or trailing zeros as
required to find the result.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220607203306.657998-12-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'target/arm/helper.c')
| -rw-r--r-- | target/arm/helper.c | 9 |
1 files changed, 2 insertions, 7 deletions
diff --git a/target/arm/helper.c b/target/arm/helper.c index de159c644c..90aac6bc12 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -6219,7 +6219,6 @@ uint32_t sve_zcr_len_for_el(CPUARMState *env, int el) { ARMCPU *cpu = env_archcpu(env); uint32_t len = cpu->sve_max_vq - 1; - uint32_t end_len; if (el <= 1 && !el_is_in_host(env, el)) { len = MIN(len, 0xf & (uint32_t)env->vfp.zcr_el[1]); @@ -6231,12 +6230,8 @@ uint32_t sve_zcr_len_for_el(CPUARMState *env, int el) len = MIN(len, 0xf & (uint32_t)env->vfp.zcr_el[3]); } - end_len = len; - if (!test_bit(len, cpu->sve_vq_map)) { - end_len = find_last_bit(cpu->sve_vq_map, len); - assert(end_len < len); - } - return end_len; + len = 31 - clz32(cpu->sve_vq_map & MAKE_64BIT_MASK(0, len + 1)); + return len; } static void zcr_write(CPUARMState *env, const ARMCPRegInfo *ri, |