diff options
Diffstat (limited to 'target')
| -rw-r--r-- | target/arm/vfp_helper.c | 47 |
1 files changed, 28 insertions, 19 deletions
diff --git a/target/arm/vfp_helper.c b/target/arm/vfp_helper.c index abfdb6a8e2..364856498c 100644 --- a/target/arm/vfp_helper.c +++ b/target/arm/vfp_helper.c @@ -194,36 +194,45 @@ void HELPER(vfp_set_fpscr)(CPUARMState *env, uint32_t val) val &= ~FPCR_FZ16; } - if (arm_feature(env, ARM_FEATURE_M)) { + vfp_set_fpscr_to_host(env, val); + + if (!arm_feature(env, ARM_FEATURE_M)) { /* - * M profile FPSCR is RES0 for the QC, STRIDE, FZ16, LEN bits - * and also for the trapped-exception-handling bits IxE. + * Short-vector length and stride; on M-profile these bits + * are used for different purposes. + * We can't make this conditional be "if MVFR0.FPShVec != 0", + * because in v7A no-short-vector-support cores still had to + * allow Stride/Len to be written with the only effect that + * some insns are required to UNDEF if the guest sets them. + * + * TODO: if M-profile MVE implemented, set LTPSIZE. */ - val &= 0xf7c0009f; + env->vfp.vec_len = extract32(val, 16, 3); + env->vfp.vec_stride = extract32(val, 20, 2); } - vfp_set_fpscr_to_host(env, val); + if (arm_feature(env, ARM_FEATURE_NEON)) { + /* + * The bit we set within fpscr_q is arbitrary; the register as a + * whole being zero/non-zero is what counts. + * TODO: M-profile MVE also has a QC bit. + */ + env->vfp.qc[0] = val & FPCR_QC; + env->vfp.qc[1] = 0; + env->vfp.qc[2] = 0; + env->vfp.qc[3] = 0; + } /* * We don't implement trapped exception handling, so the * trap enable bits, IDE|IXE|UFE|OFE|DZE|IOE are all RAZ/WI (not RES0!) * - * If we exclude the exception flags, IOC|DZC|OFC|UFC|IXC|IDC - * (which are stored in fp_status), and the other RES0 bits - * in between, then we clear all of the low 16 bits. + * The exception flags IOC|DZC|OFC|UFC|IXC|IDC are stored in + * fp_status; QC, Len and Stride are stored separately earlier. + * Clear out all of those and the RES0 bits: only NZCV, AHP, DN, + * FZ, RMode and FZ16 are kept in vfp.xregs[FPSCR]. */ env->vfp.xregs[ARM_VFP_FPSCR] = val & 0xf7c80000; - env->vfp.vec_len = (val >> 16) & 7; - env->vfp.vec_stride = (val >> 20) & 3; - - /* - * The bit we set within fpscr_q is arbitrary; the register as a - * whole being zero/non-zero is what counts. - */ - env->vfp.qc[0] = val & FPCR_QC; - env->vfp.qc[1] = 0; - env->vfp.qc[2] = 0; - env->vfp.qc[3] = 0; } void vfp_set_fpscr(CPUARMState *env, uint32_t val) |