For A64, any input to an indirect branch can cause this.
For A32, many indirect branch paths force the branch to be aligned,
but BXWritePC does not. This includes the BX instruction but also
other interworking changes to PC. Prior to v8, this case is UNDEFINED.
With v8, this is CONSTRAINED UNPREDICTABLE and may either raise an
exception or force align the PC.
We choose to raise an exception because we have the infrastructure,
it makes the generated code for gen_bx simpler, and it has the
possibility of catching more guest bugs.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
In v7A, the HSTR register has a TJDBX bit which traps NS EL0/EL1
access to the JOSCR and JMCR trivial Jazelle registers, and also BXJ.
Implement these traps. In v8A this HSTR bit doesn't exist, so don't
trap for v8A CPUs.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210816180305.20137-3-peter.maydell@linaro.org
Unlike A-profile, for M-profile the UDIV and SDIV insns can be
configured to raise an exception on division by zero, using the CCR
DIV_0_TRP bit.
Implement support for setting this bit by making the helper functions
raise the appropriate exception.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210730151636.17254-3-peter.maydell@linaro.org
Implement the forms of the MVE VLDR and VSTR insns which perform
non-widening loads of bytes, halfwords or words from memory into
vector elements of the same width (encodings T5, T6, T7).
(At the moment we know for MVE and M-profile in general that
vfp_access_check() can never return false, but we include the
conventional return-true-on-failure check for consistency
with non-M-profile translation code.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210617121628.20116-2-peter.maydell@linaro.org
The helper function did not get updated when we reorganized
the vector register file for SVE. Since then, the neon dregs
are non-sequential and cannot be simply indexed.
At the same time, make the helper function operate on 64-bit
quantities so that we do not have to call it twice.
Fixes: c39c2b9043
Reported-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
[PMM: use aa32_vfp_dreg() rather than opencoding]
Message-id: 20201105171126.88014-1-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
For AArch32, unlike the VCVT of integer to float, which honours the
rounding mode specified by the FPSCR, VCVT of fixed-point to float is
always round-to-nearest. (AArch64 fixed-point-to-float conversions
always honour the FPCR rounding mode.)
Implement this by providing _round_to_nearest versions of the
relevant helpers which set the rounding mode temporarily when making
the call to the underlying softfloat function.
We only need to change the VFP VCVT instructions, because the
standard- FPSCR value used by the Neon VCVT is always set to
round-to-nearest, so we don't need to do the extra work of saving
and restoring the rounding mode.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201013103532.13391-1-peter.maydell@linaro.org
Convert the Neon float-integer VCVT insns to gvec, and use this
to implement fp16 support for them.
Note that unlike the VFP int<->fp16 VCVT insns we converted
earlier and which convert to/from a 32-bit integer, these
Neon insns convert to/from 16-bit integers. So we can use
the existing vfp conversion helpers for the f32<->u32/i32
case but need to provide our own for f16<->u16/i16.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200828183354.27913-37-peter.maydell@linaro.org
Convert the Neon VRECPS insn to using a gvec helper, and
use this to implement the fp16 case.
The phrasing of the new float32_recps_nf() is slightly different from
the old recps_f32() so that it parallels the f16 version; for f16 we
can't assume that flush-to-zero is always enabled.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200828183354.27913-34-peter.maydell@linaro.org
Convert the Neon floating-point vector comparison ops VCEQ,
VCGE and VCGT over to using a gvec helper and use this to
implement the fp16 case.
(We put the float16_ceq() etc functions above the DO_2OP()
macro definition because later when we convert the
compare-against-zero instructions we'll want their
definitions to be visible at that point in the source file.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200828183354.27913-27-peter.maydell@linaro.org
Implement FP16 support for the Neon insns which use the DO_3S_FP_GVEC
macro: VADD, VSUB, VABD, VMUL.
For VABD this requires us to implement a new gvec_fabd_h helper
using the machinery we have already for the other helpers.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200828183354.27913-24-peter.maydell@linaro.org
Now the VFP_CONV_FIX macros can handle fp16's distinction between the
width of the operation and the width of the type used to pass operands,
use the macros rather than the open-coded functions.
This creates an extra six helper functions, all of which we are going
to need for the AArch32 VFP fp16 instructions.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200828183354.27913-15-peter.maydell@linaro.org
Implement VFP fp16 for VABS, VNEG and VSQRT. This is all
the fp16 insns that use the DO_VFP_2OP macro, because there
is no fp16 version of VMOV_reg.
Notes:
* the gen_helper_vfp_negh already exists as we needed to create
it for the fp16 multiply-add insns
* as usual we need to use the f16 version of the fp_status;
this is only relevant for VSQRT
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200828183354.27913-9-peter.maydell@linaro.org
Implmeent VFP fp16 support for simple binary-operator VFP insns VADD,
VSUB, VMUL, VDIV, VMINNM and VMAXNM:
* make the VFP_BINOP() macro generate float16 helpers as well as
float32 and float64
* implement a do_vfp_3op_hp() function similar to the existing
do_vfp_3op_sp()
* add decode for the half-precision insn patterns
Note that the VFP_BINOP macro use creates a couple of unused helper
functions vfp_maxh and vfp_minh, but they're small so it's not worth
splitting the BINOP operations into "needs halfprec" and "no
halfprec" groups.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200828183354.27913-4-peter.maydell@linaro.org
