Commit graph

96 commits

Author SHA1 Message Date
Peter Maydell 2c6e54d1cd target/arm: Implement M-profile FPSCR_nzcvqc
v8.1M defines a new FP system register FPSCR_nzcvqc; this behaves
like the existing FPSCR, except that it reads and writes only bits
[31:27] of the FPSCR (the N, Z, C, V and QC flag bits). (Unlike the
FPSCR, the special case for Rt=15 of writing the CPSR.NZCV is not
permitted.)

Implement the register. Since we don't yet implement MVE, we handle
the QC bit as RES0, with todo comments for where we will need to add
support later.

Backports 9542c30bcf13c495400d63616dd8dfa825b04685
2021-03-03 18:45:38 -05:00
Peter Maydell 56532aa94c target/arm: Implement VLDR/VSTR system register
Implement the new-in-v8.1M VLDR/VSTR variants which directly
read or write FP system registers to memory.

Backports 0bf0dd4dcbd9fab324700ac6e0cd061cd043de0d
2021-03-03 18:42:05 -05:00
Peter Maydell a72c744370 target/arm: Refactor M-profile VMSR/VMRS handling
Currently M-profile borrows the A-profile code for VMSR and VMRS
(access to the FP system registers), because all it needs to support
is the FPSCR. In v8.1M things become significantly more complicated
in two ways:

* there are several new FP system registers; some have side effects
on read, and one (FPCXT_NS) needs to avoid the usual
vfp_access_check() and the "only if FPU implemented" check

* all sysregs are now accessible both by VMRS/VMSR (which
reads/writes a general purpose register) and also by VLDR/VSTR
(which reads/writes them directly to memory)

Refactor the structure of how we handle VMSR/VMRS to cope with this:

* keep the M-profile code entirely separate from the A-profile code

* abstract out the "read or write the general purpose register" part
of the code into a loadfn or storefn function pointer, so we can
reuse it for VLDR/VSTR.

Backports 32a290b8c3c2dc85cd88bd8983baf900d575cab
2021-03-03 18:13:17 -05:00
Peter Maydell 4eafe42d67 target/arm: Enforce M-profile VMRS/VMSR register restrictions
For M-profile before v8.1M, the only valid register for VMSR/VMRS is
the FPSCR. We have a comment that states this, but the actual logic
to forbid accesses for any other register value is missing, so we
would end up with A-profile style behaviour. Add the missing check.

Backports ede97c9d71110821738a48f88ff9f10d6bec017f
2021-03-03 18:06:23 -05:00
Peter Maydell 43d8441881 target/arm: Implement VSCCLRM insn
Implement the v8.1M VSCCLRM insn, which zeros floating point
registers if there is an active floating point context.
This requires support in write_neon_element32() for the MO_32
element size, so add it.

Because we want to use arm_gen_condlabel(), we need to move
the definition of that function up in translate.c so it is
before the #include of translate-vfp.c.inc.

Backports 83ff3d6add965c9752324de11eac5687121ea826
2021-03-03 17:57:30 -05:00
Chetan Pant c7f6786089 arm tcg cpus: Fix Lesser GPL version number
There is no "version 2" of the "Lesser" General Public License.
It is either "GPL version 2.0" or "Lesser GPL version 2.1".
This patch replaces all occurrences of "Lesser GPL version 2" with
"Lesser GPL version 2.1" in comment section.

Backports 50f57e09fda4b7ffbc5ba62aad6cebf660824023
2021-03-02 13:30:35 -05:00
Richard Henderson 07c2b70234 target/arm: Rename neon_load_reg64 to vfp_load_reg64
The only uses of this function are for loading VFP
double-precision values, and nothing to do with NEON.

Backports b38b96ca90827012ab8eb045c1337cea83a54c4b
2021-03-02 12:43:25 -05:00
Richard Henderson 89b1f62878 target/arm: Rename neon_load_reg32 to vfp_load_reg32
The only uses of this function are for loading VFP
single-precision values, and nothing to do with NEON.

Backports 21c1c0e50b73c580c6bfc8f2314d1b6a14793561
2021-03-02 12:30:20 -05:00
Richard Henderson 011d9ab061 target/arm: Expand read/write_neon_element32 to all MemOp
We can then use this to improve VMOV (scalar to gp) and
VMOV (gp to scalar) so that we simply perform the memory
operation that we wanted, rather than inserting or
extracting from a 32-bit quantity.

These were the last uses of neon_load/store_reg, so remove them.

Backports 4d5fa5a80ac28f34b8497be1e85371272413a12e
2021-03-02 12:26:41 -05:00
Richard Henderson 8a20537e7f target/arm: Introduce neon_full_reg_offset
This function makes it clear that we're talking about the whole
register, and not the 32-bit piece at index 0. This fixes a bug
when running on a big-endian host.

Backports 015ee81a4c06b644969f621fd9965cc6372b879e
2021-03-02 11:50:36 -05:00
Peter Maydell 2dae268fcb target/arm: Implement v8.1M NOCP handling
From v8.1M, disabled-coprocessor handling changes slightly:
* coprocessors 8, 9, 14 and 15 are also governed by the
cp10 enable bit, like cp11
* an extra range of instruction patterns is considered
to be inside the coprocessor space

We previously marked these up with TODO comments; implement the
correct behaviour.

Unfortunately there is no ID register field which indicates this
behaviour. We could in theory test an unrelated ID register which
indicates guaranteed-to-be-in-v8.1M behaviour like ID_ISAR0.CmpBranch
>= 3 (low-overhead-loops), but it seems better to simply define a new
ARM_FEATURE_V8_1M feature flag and use it for this and other
new-in-v8.1M behaviour that isn't identifiable from the ID registers.

Backports commit 5d2555a1fe7370feeb1efbbf276a653040910017
2021-03-01 20:16:09 -05:00
Peter Maydell d350644817 target/arm: AArch32 VCVT fixed-point to float is always round-to-nearest
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.

Backports commit 61db12d9f9eb36761edba4d9a414cd8dd34c512b
2021-03-01 20:04:31 -05:00
Peter Maydell 08b70267d0 target/arm: Implement VFP fp16 VMOV between gp and halfprec registers
Implement the VFP fp16 variant of VMOV that transfers a 16-bit
value between a general purpose register and a VFP register.

Note that Rt == 15 is UNPREDICTABLE; since this insn is v8 and later
only we have no need to replicate the old "updates CPSR.NZCV"
behaviour that the singleprec version of this insn does

Backports commit 46a4b854525cb9f34a611f6ada6cdff1eab0ac2d
2021-03-01 16:26:34 -05:00
Peter Maydell 58485bca97 target/arm: Implement new VFP fp16 insn VMOVX
The fp16 extension includes a new instruction VMOVX, which copies the
upper 16 bits of a 32-bit source VFP register into the lower 16
bits of the destination and zeroes the high half of the destination.
Implement it.

Backports f61e5c43b86907dea17f431b528d806659d62bcb
2021-03-01 16:24:50 -05:00
Peter Maydell 3dd587e3df target/arm: Implement new VFP fp16 insn VINS
The fp16 extension includes a new instruction VINS, which copies the
lower 16 bits of a 32-bit source VFP register into the upper 16 bits
of the destination. Implement it.

Backports commit e4875e3bcc3a9c54d7e074c8f51e04c2e6364e2e
2021-03-01 16:22:27 -05:00
Peter Maydell 90aa9647e0 target/arm: Implement VFP fp16 VRINT*
Implement the fp16 version of the VFP VRINT* insns.

Backports 0a6f4b4cb338665b81ad824d9a6868932461b7f7
2021-03-01 16:15:21 -05:00
Peter Maydell 1c8088b48a target/arm: Implement VFP fp16 VSEL
Implement the fp16 versions of the VFP VSEL instruction.

Backports commit 11e78fecdf2d605cfed33aa09bbcf0cc4fb95886
2021-03-01 16:08:51 -05:00
Peter Maydell beee4ad7f3 target/arm: Implement VFP vp16 VCVT-with-specified-rounding-mode
Implement the fp16 versions of the VFP VCVT instruction forms
which convert between floating point and integer with a specified
rounding mode.

Backports c505bc6a9d50a48f9d89d6cf930e863838a5b367
2021-02-28 05:18:07 -05:00
Peter Maydell 74a6af4e23 target/arm: Implement VFP fp16 VCVT between float and fixed-point
Implement the fp16 versions of the VFP VCVT instruction forms which
convert between floating point and fixed-point.

Backports a149e2de0b63e3906729ed1d3df7d9ecdb6de5e6
2021-02-28 05:15:40 -05:00
Peter Maydell dd6e11eaa7 target/arm: Make VFP_CONV_FIX macros take separate float type and float size
Currently the VFP_CONV_FIX macros take a single fsz argument for the
size of the float type, which is used both to select the name of
the functions to call (eg float32_is_any_nan()) and also for the
type to use for the float inputs and outputs (eg float32).

Separate these into fsz and ftype arguments, so that we can use them
for fp16, which uses 'float16' in the function names but is still
passing inputs and outputs in a 32-bit sized type.

Backports 5366f6ad7da4f6def2733ec7ee24495430256839
2021-02-28 05:05:53 -05:00
Peter Maydell f8241ae22f target/arm: Implement VFP fp16 VCVT between float and integer
Backports 0094e9f475a5a742d10d2f1e1beceea82b69f982
2021-02-28 05:02:25 -05:00
Peter Maydell ac9ae5cbe7 target/arm: Implement VFP fp16 VLDR and VSTR
Implement the fp16 versions of the VFP VLDR/VSTR (immediate).

Backports commit 274afbb121107b8aaeaa11b3e7904d5f8ae38a94
2021-02-28 04:58:32 -05:00
Peter Maydell 5d98e14545 target/arm: Implement VFP fp16 VCMP
Implement fp16 version of VCMP.

Backports 1b88b054c5b201e8581114d29527c6a5a7e088c9
2021-02-28 04:56:24 -05:00
Peter Maydell 25d95570f3 target/arm: Implement VFP fp16 for VMOV immediate
Implement VFP fp16 support for the VMOV immediate insn.

Backports commit 28c28728e53c9f4c13a5cd50f313788c7ec2f9ad
2021-02-28 04:51:11 -05:00
Peter Maydell 2d9abf7c0b target/arm: Implement VFP fp16 for VABS, VNEG, VSQRT
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

Backports ce2d65a5d191380756cdac7a1fd1ba76bd1621cf
2021-02-28 04:48:28 -05:00
Peter Maydell f3af6b8c25 target/arm: Macroify uses of do_vfp_2op_sp() and do_vfp_2op_dp()
Macroify the uses of do_vfp_2op_sp() and do_vfp_2op_dp(); this will
make it easier to add the halfprec support.

Backports 009a07335b8ff492d940e1eb229a1b0d302c2512
2021-02-28 04:43:01 -05:00
Peter Maydell 6ac2c597ab target/arm: Implement VFP fp16 for fused-multiply-add
Implement VFP fp16 support for fused multiply-add insns
VFNMA, VFNMS, VFMA, VFMS.

Backports 9886fe2834b064a3cf0675a4659942ed547aed42
2021-02-28 04:39:21 -05:00
Peter Maydell f86c84425b target/arm: Macroify trans functions for VFMA, VFMS, VFNMA, VFNMS
Macroify creation of the trans functions for single and double
precision VFMA, VFMS, VFNMA, VFNMS. The repetition was OK for
two sizes, but we're about to add halfprec and it will get a bit
more than seems reasonable.

Backports 2aa8dcfa14558fe2a63ed0496d60b02565c9a225
2021-02-28 04:36:07 -05:00
Peter Maydell a42ecfe203 target/arm: Implement VFP fp16 VMLA, VMLS, VNMLS, VNMLA, VNMUL
Implement fp16 versions of the VFP VMLA, VMLS, VNMLS, VNMLA, VNMUL
instructions. (These are all the remaining ones which we implement
via do_vfp_3op_[hsd]p().)

Backports commit e7cb0ded52c6d7b86585b09935fe7caeb9e38b69
2021-02-28 04:29:37 -05:00
Peter Maydell eae621098d target/arm: Implement VFP fp16 for VFP_BINOP operations
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.

Backports commit 120a0eb3ea23a5b06fae2f3daebd46a4035864cf
2021-02-28 04:24:39 -05:00
Peter Maydell b1b0a41507 target/arm: Make A32/T32 use new fpstatus_ptr() API
Make A32/T32 code use the new fpstatus_ptr() API:
get_fpstatus_ptr(0) -> fpstatus_ptr(FPST_FPCR)
get_fpstatus_ptr(1) -> fpstatus_ptr(FPST_STD)

Backports a84d1d1316726704edd2617b2c30c921d98a8137
2021-02-26 11:55:55 -05:00
Peter Maydell bdaaac68f5 target/arm: Do M-profile NOCP checks early and via decodetree
For M-profile CPUs, the architecture specifies that the NOCP
exception when a coprocessor is not present or disabled should cover
the entire wide range of coprocessor-space encodings, and should take
precedence over UNDEF exceptions. (This is the opposite of
A-profile, where checking for a disabled FPU has to happen last.)

Implement this with decodetree patterns that cover the specified
ranges of the encoding space. There are a few instructions (VLLDM,
VLSTM, and in v8.1 also VSCCLRM) which are in copro-space but must
not be NOCP'd: these must be handled also in the new m-nocp.decode so
they take precedence.

This is a minor behaviour change: for unallocated insn patterns in
the VFP area (cp=10,11) we will now NOCP rather than UNDEF when the
FPU is disabled.

As well as giving us the correct architectural behaviour for v8.1M
and the recommended behaviour for v8.0M, this refactoring also
removes the old NOCP handling from the remains of the 'legacy
decoder' in disas_thumb2_insn(), paving the way for cleaning that up.

Since we don't currently have a v8.1M feature bit or any v8.1M CPUs,
the minor changes to this logic that we'll need for v8.1M are marked
up with TODO comments.

Backports commit a3494d4671797c291c88bd414acb0aead15f7239 from qemu
2021-02-26 11:17:23 -05:00
Richard Henderson eaa6291aa7 target/arm: Rename DISAS_UPDATE to DISAS_UPDATE_EXIT
Emphasize that the is_jmp option exits to the main loop.

Backports commit 14407ec2007e18536ed34772eef46f6e0a0e3d0e from qemu
2021-02-25 14:02:46 -05:00
Peter Maydell 167ed57625 target/arm: Remove unnecessary gen_io_end() calls
Since commit ba3e7926691ed3 it has been unnecessary for target code
to call gen_io_end() after an IO instruction in icount mode; it is
sufficient to call gen_io_start() before it and to force the end of
the TB.

Many now-unnecessary calls to gen_io_end() were removed in commit
9e9b10c6491153b, but some were missed or accidentally added later.
Remove unneeded calls from the arm target:

* the call in the handling of exception-return-via-LDM is
unnecessary, and the code is already forcing end-of-TB
* the call in the VFP access check code is more complicated:
we weren't ending the TB, so we need to add the code to
force that by setting DISAS_UPDATE
* the doc comment for ARM_CP_IO doesn't need to mention
gen_io_end() any more

Backports commit 55c812b74289863c348449135812027d188f040a from qemu
2021-02-25 13:17:32 -05:00
Peter Maydell bb0aa79847 target/arm: Convert Neon VADD, VSUB, VABD 3-reg-same insns to decodetree
Convert the Neon VADD, VSUB, VABD 3-reg-same insns to decodetree.
We already have gvec helpers for addition and subtraction, but must
add one for fabd.

Backports commit a26a352bb498662cd0c205cb433a352f86fac7d2 from qemu
2020-05-15 23:26:51 -04:00
MerryMage 9255fbce96 target/arm: Introduce add_reg_for_lit (fixup)
Backports commit 16e0d8234ef9291747332d2c431e46808a060472 from qemu

Missed from original backporting commit a2e60445de
2020-05-10 12:30:52 +01:00
Peter Maydell 1964e4b9c9 target/arm/translate-vfp.inc.c: Remove duplicate simd_r32 check
Somewhere along theline we accidentally added a duplicate
"using D16-D31 when they don't exist" check to do_vfm_dp()
(probably an artifact of a patchseries rebase). Remove it.

Backports commit 0d787cf1f3c88fa29477e054f8523f6d82d91c98 from qemu
2020-05-07 08:52:42 -04:00
Richard Henderson c3eaaf7c33 target/arm: Split VMINMAXNM decode
Passing the raw op field from the manual is less instructive
than it might be. Do the full decode and use the existing
helpers to perform the expansion.

Since these are v8 insns, VECLEN+VECSTRIDE are already RES0.

Backports commit f2eafb75511e5d2ee601b43dc6ee0bcc6e453acd from qemu
2020-03-22 00:09:53 -04:00
Richard Henderson 303d922e5d target/arm: Split VFM decode
Passing the raw o1 and o2 fields from the manual is less
instructive than it might be. Do the full decode and let
the trans_* functions pass in booleans to a helper.

Backports commit d486f8308a13543bbcc4887f246e856df991a4bc from qemu
2020-03-22 00:07:53 -04:00
Richard Henderson f1ce64857c target/arm: Move VLLDM and VLSTM to vfp.decode
Now that we no longer have an early check for ARM_FEATURE_VFP,
we can use the proper ISA check in trans_VLLDM_VLSTM.

Backports commit dc778a6873f534817a13257be2acba3ca87ec015 from qemu
2020-03-21 23:51:59 -04:00
Richard Henderson 3f0ae7ccee target/arm: Replace ARM_FEATURE_VFP4 with isar_feature_aa32_simdfmac
All remaining tests for VFP4 are for fused multiply-add insns.

Since the MVFR1 field is used for both VFP and NEON, move its adjustment
from the !has_neon block to the (!has_vfp && !has_neon) block.

Test for vfp of the appropraite width alongside the test for simdfmac
within translate-vfp.inc.c. Within disas_neon_data_insn, we have
already tested for ARM_FEATURE_NEON.

Backports commit c52881bbc22b50db99a6c37171ad3eea7d959ae6 from qemu
2020-03-21 23:48:13 -04:00
Richard Henderson f6b5a9ef81 target/arm: Add missing checks for fpsp_v2
We will eventually remove the early ARM_FEATURE_VFP test,
so add a proper test for each trans_* that does not already
have another ISA test.

Backports commit 82f6abe16b9b951180657c5fe15942d5214aa12e from qemu
2020-03-21 23:42:27 -04:00
Richard Henderson ed1ce1437a target/arm: Replace ARM_FEATURE_VFP3 checks with fp{sp, dp}_v3
Sort this check to the start of a trans_* function.
Merge this with any existing test for fpdp_v2.

Backports commit 84774cc37f2c17e48a4867a8e8e055deb23bea69 from qemu
2020-03-21 23:33:13 -04:00
Richard Henderson 54e9ce5174 target/arm: Perform fpdp_v2 check first
Shuffle the order of the checks so that we test the ISA
before we test anything else, such as the register arguments.

Backports commit 799449abda137153a0e68b8788d8e1486f389490 from qemu
2020-03-21 23:29:08 -04:00
Richard Henderson f73b360f8e target/arm: Rename isar_feature_aa32_fpdp_v2
The old name, isar_feature_aa32_fpdp, does not reflect
that the test includes VFPv2. We will introduce another
feature tests for VFPv3.

Backports commit c4ff873583834c8275586914fff714e3ae65dee4 from qemu
2020-03-21 23:16:00 -04:00
Richard Henderson c06fd38b57 target/arm: Rename isar_feature_aa32_simd_r32
The old name, isar_feature_aa32_fp_d32, does not reflect
the MVFR0 field name, SIMDReg.

Backports commit 0e13ba7889432c5e2f1bdb1b25e7076ca1b1dcba from qemu
2020-03-21 19:37:33 -04:00
Marc Zyngier 868de52f69 target/arm: Handle trapping to EL2 of AArch32 VMRS instructions
HCR_EL2.TID3 requires that AArch32 reads of MVFR[012] are trapped to
EL2, and HCR_EL2.TID0 does the same for reads of FPSID.
In order to handle this, introduce a new TCG helper function that
checks for these control bits before executing the VMRC instruction.

Tested with a hacked-up version of KVM/arm64 that sets the control
bits for 32bit guests.

Backports commit 9ca1d776cb49c09b09579d9edd0447542970c834 from qemu
2020-01-07 18:04:16 -05:00
Richard Henderson 87c06b7fae
target/arm: Factor out unallocated_encoding for aarch32
Make this a static function private to translate.c.
Thus we can use the same idiom between aarch64 and aarch32
without actually sharing function implementations.

Backports commit 1ce21ba1eaf08b22da5925f3e37fc0b4322da858 from qemu
2019-11-18 23:51:45 -05:00
Richard Henderson 1f59a43544
Revert "target/arm: Use unallocated_encoding for aarch32"
Despite the fact that the text for the call to gen_exception_insn
is identical for aarch64 and aarch32, the implementation inside
gen_exception_insn is totally different.

This fixes exceptions raised from aarch64.

This reverts commit fb2d3c9a9a.
2019-11-18 23:49:47 -05:00
Richard Henderson fb2d3c9a9a
target/arm: Use unallocated_encoding for aarch32
Promote this function from aarch64 to fully general use.
Use it to unify the code sequences for generating illegal
opcode exceptions.

Backports commit 3cb36637157088892e9e33ddb1034bffd1251d3b from qemu
2019-11-18 20:10:50 -05:00