In StreamingMode, fp_access_checked is handled already.
We cannot fall through to fp_access_check lest we fall
foul of the double-check assertion.
Cc: qemu-stable@nongnu.org
Fixes: 285b1d5fcef ("target/arm: Handle SME in sve_access_check")
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250307190415.982049-3-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: move declaration of 'ret' to top of block]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The check for fp_excp_el in assert_fp_access_checked is
incorrect. For SME, with StreamingMode enabled, the access
is really against the streaming mode vectors, and access
to the normal fp registers is allowed to be disabled.
C.f. sme_enabled_check.
Convert sve_access_checked to match, even though we don't
currently check the exception state.
Cc: qemu-stable@nongnu.org
Fixes: 3d74825f4d6 ("target/arm: Add SME enablement checks")
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250307190415.982049-2-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
FEAT_RPRES implements an "increased precision" variant of the single
precision FRECPE and FRSQRTE instructions from an 8 bit to a 12
bit mantissa. This applies only when FPCR.AH == 1. Note that the
halfprec and double versions of these insns retain the 8 bit
precision regardless.
In this commit we add all the plumbing to make these instructions
call a new helper function when the increased-precision is in
effect. In the following commit we will provide the actual change
in behaviour in the helpers.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
The negation step in FCMLA by index mustn't negate a NaN when
FPCR.AH is set. Use the same approach as vector FCMLA of
passing in FPCR.AH and using it to select whether to negate
by XOR or by the muladd negate_product flag.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250129013857.135256-27-richard.henderson@linaro.org
[PMM: Expanded commit message]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
The negation step in FCMLA mustn't negate a NaN when FPCR.AH
is set. Handle this by passing FPCR.AH to the helper via the
SIMD data field, and use this to select whether to do the
negation via XOR or via the muladd negate_product flag.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250129013857.135256-26-richard.henderson@linaro.org
[PMM: Expanded commit message]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Handle the FPCR.AH "don't negate the sign of a NaN" semantics
in FMLS (vector), by implementing a new set of helpers for
the AH=1 case.
The float_muladd_negate_product flag produces the same result
as negating either of the multiplication operands, assuming
neither of the operands are NaNs. But since FEAT_AFP does not
negate NaNs, this behaviour is exactly what we need.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Handle the FPCR.AH "don't negate the sign of a NaN" semantics in FMLS
(indexed). We do this by creating 6 new helpers, which allow us to
do the negation either by XOR (for AH=0) or by muladd flags
(for AH=1).
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: Mostly from RTH's patch; error in index order into fns[][]
fixed]
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Handle the FPCR.AH "don't negate the sign of a NaN" semantics
in the vector versions of FRECPS and FRSQRTS, by implementing
new vector wrappers that call the _ah_ scalar helpers.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Handle the FPCR.AH semantics that we do not change the sign of an
input NaN in the FRECPS and FRSQRTS scalar insns, by providing
new helper functions that do the CHS part of the operation
differently.
Since the extra helper functions would be very repetitive if written
out longhand, we condense them and the existing non-AH helpers into
being emitted via macros.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
The negation steps in FCADD must honour FPCR.AH's "don't change the
sign of a NaN" semantics. Implement this by encoding FPCR.AH into
the SIMD data field passed to the helper and using that to decide
whether to negate the values.
The construction of neg_imag and neg_real were done to make it easy
to apply both in parallel with two simple logical operations. This
changed with FPCR.AH, which is more complex than that. Switch to
an approach closer to the pseudocode, where we extract the rot
parameter from the SIMD data word and negate the appropriate
input value.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Split the handling of vector FABD so that it calls a different set
of helpers when FPCR.AH is 1, which implement the "no negation of
the sign of a NaN" semantics.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
FPCR.AH == 1 mandates that taking the absolute value of a NaN should
not change its sign bit. This means we can no longer use
gen_vfp_abs*() everywhere but must instead generate slightly more
complex code when FPCR.AH is set.
Implement these semantics for scalar FABS and FABD. This change also
affects all other instructions whose psuedocode calls FPAbs(); we
will extend the change to those instructions in following commits.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
FPCR.AH == 1 mandates that negation of a NaN value should not flip
its sign bit. This means we can no longer use gen_vfp_neg*()
everywhere but must instead generate slightly more complex code when
FPCR.AH is set.
Make this change for the scalar FNEG and for those places in
translate-a64.c which were previously directly calling
gen_vfp_neg*().
This change in semantics also affects any other instruction whose
pseudocode calls FPNeg(); in following commits we extend this
change to the other affected instructions.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Implement the FPCR.AH semantics for the pairwise floating
point minimum/maximum insns FMINP and FMAXP.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Implement the FPCR.AH semantics for FMAXV and FMINV. These are the
"recursively reduce all lanes of a vector to a scalar result" insns;
we just need to use the _ah_ helper for the reduction step when
FPCR.AH == 1.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Implement the FPCR.AH == 1 semantics for vector FMIN/FMAX, by
creating new _ah_ versions of the gvec helpers which invoke the
scalar fmin_ah and fmax_ah helpers on each element.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
When FPCR.AH == 1, floating point FMIN and FMAX have some odd special
cases:
* comparing two zeroes (even of different sign) or comparing a NaN
with anything always returns the second argument (possibly
squashed to zero)
* denormal outputs are not squashed to zero regardless of FZ or FZ16
Implement these semantics in new helper functions and select them at
translate time if FPCR.AH is 1 for the scalar FMAX and FMIN insns.
(We will convert the other FMAX and FMIN insns in subsequent
commits.)
Note that FMINNM and FMAXNM are not affected.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
do_fp3_scalar_idx() is used only for the FMUL and FMULX scalar by
element instructions; these both need to merge the result with the Rn
register when FPCR.NEP is set.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Unlike the other users of do_2misc_narrow_scalar(), FCVTXN (scalar)
is always double-to-single and must honour FPCR.NEP. Implement this
directly in a trans function rather than using
do_2misc_narrow_scalar().
We still need gen_fcvtxn_sd() and the f_scalar_fcvtxn[] array for
the FCVTXN (vector) insn, so we move those down in the file to
where they are used.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Handle FPCR.NEP merging for scalar FABS and FNEG; this requires
an extra parameter to do_fp1_scalar_int(), since FMOV scalar
does not have the merging behaviour.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Handle FPCR.NEP in the operations handled by do_cvtf_scalar().
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Handle FPCR.NEP for the 1-input scalar operations.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Currently we implement BFCVT scalar via do_fp1_scalar(). This works
even though BFCVT is a narrowing operation from 32 to 16 bits,
because we can use write_fp_sreg() for float16. However, FPCR.NEP
support requires that we use write_fp_hreg_merging() for float16
outputs, so we can't continue to borrow the non-narrowing
do_fp1_scalar() function for this. Split out trans_BFCVT_s()
into its own implementation that honours FPCR.NEP.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Handle FPCR.NEP for the 3-input scalar operations which use
do_fmla_scalar_idx() and do_fmadd(), by making them call the
appropriate write_fp_*reg_merging() functions.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
For FEAT_AFP's FPCR.NEP bit, we need to programmatically change the
behaviour of the writeback of the result for most SIMD scalar
operations, so that instead of zeroing the upper part of the result
register it merges the upper elements from one of the input
registers.
Provide new functions write_fp_*reg_merging() which can be used
instead of the existing write_fp_*reg() functions when we want this
"merge the result with one of the input registers if FPCR.NEP is
enabled" handling, and use them in do_fp3_scalar_with_fpsttype().
Note that (as documented in the description of the FPCR.NEP bit)
which input register to use as the merge source varies by
instruction: for these 2-input scalar operations, the comparison
instructions take from Rm, not Rn.
We'll extend this to also provide the merging behaviour for
the remaining scalar insns in subsequent commits.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
For FEAT_AFP, we want to emit different code when FPCR.NEP is set, so
that instead of zeroing the high elements of a vector register when
we write the output of a scalar operation to it, we instead merge in
those elements from one of the source registers. Since this affects
the generated code, we need to put FPCR.NEP into the TBFLAGS.
FPCR.NEP is treated as 0 when in streaming SVE mode and FEAT_SME_FA64
is not implemented or not enabled; we can implement this logic in
rebuild_hflags_a64().
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
When FPCR.AH is 1, use FPST_FPCR_AH for:
* AdvSIMD BFMLALB, BFMLALT
* SVE BFMLALB, BFMLALT, BFMLSLB, BFMLSLT
so that they get the required behaviour changes.
We do this by making gen_gvec_op4_fpst() take an ARMFPStatusFlavour
rather than a bool is_fp16; existing callsites now select
FPST_FPCR_F16_A64 vs FPST_FPCR_A64 themselves rather than passing in
the boolean.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
When FPCR.AH is 1, use FPST_FPCR_AH for:
* AdvSIMD BFCVT, BFCVTN, BFCVTN2
* SVE BFCVT, BFCVTNT
so that they get the required behaviour changes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
For the instructions FRECPE, FRECPS, FRECPX, FRSQRTE, FRSQRTS, use
FPST_FPCR_AH or FPST_FPCR_AH_F16 when FPCR.AH is 1, so that they get
the required behaviour changes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
We are going to need to generate different code in some cases when
FPCR.AH is 1. For example:
* Floating point neg and abs must not flip the sign bit of NaNs
* some insns (FRECPE, FRECPS, FRECPX, FRSQRTE, FRSQRTS, and various
BFCVT and BFM bfloat16 ops) need to use a different float_status
to the usual one
Encode FPCR.AH into the A64 tbflags, so we can refer to it at
translate time.
Because we now have a bit in FPCR that affects codegen, we can't mark
the AArch64 FPCR register as being SUPPRESS_TB_END any more; writes
to it will now end the TB and trigger a regeneration of hflags.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
We removed the old table-based decoder in favour of decodetree, but
we left a couple of typedefs that are now unused; delete them.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250128135046.4108775-1-peter.maydell@linaro.org
We should be using the F16-specific float_status for conversions from
half-precision, because halfprec inputs never set Input Denormal.
Without FEAT_AHP, using the wrong fpst here had no effect, because
the only difference between the A64_F16 and A64 fpst is its handling
of flush-to-zero on input and output, and the helper functions
vfp_fcvt_f16_to_* and vfp_fcvt_*_to_f16 all explicitly squash the
relevant flushing flags, and flush_inputs_to_zero was the only way
that IDC could be set.
With FEAT_AHP, the FPCR.AH=1 behaviour sets IDC for
input_denormal_used, which we will only ignore in
vfp_get_fpsr_from_host() for the A64_F16 fpst; so it matters that we
use that one for f16 inputs (and the normal one for single/double to
f16 conversions).
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250124162836.2332150-27-peter.maydell@linaro.org
The advsimd_addh etc helpers defined in helper-a64.c are identical to
the vfp_addh etc helpers defined in helper-vfp.c: both take two
float16 inputs (in a uint32_t type) plus a float_status* and are
simple wrappers around the softfloat float16_* functions.
(The duplication seems to be a historical accident: we added the
advsimd helpers in 2018 as part of the A64 implementation, and at
that time there was no f16 emulation in A32. Then later we added the
A32 f16 handling by extending the existing VFP helper macros to
generate f16 versions as well as f32 and f64, and didn't realise we
could clean things up.)
Remove the now-unnecessary advsimd helpers and make the places that
generated calls to them use the vfp helpers instead. Many of the
helper functions were already unused.
(The remaining advsimd_ helpers are those which don't have vfp
versions.)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250124162836.2332150-26-peter.maydell@linaro.org
In the A32 decoder, use FPST_A64_F16 rather than FPST_FPCR_F16.
By doing an automated conversion of the whole file we avoid possibly
using more than one fpst value in a set_rmode/op/restore_rmode
sequence.
Patch created with
perl -p -i -e 's/FPST_FPCR_F16(?!_)/FPST_A64_F16/g' target/arm/tcg/translate-{a64,sve,sme}.c
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250124162836.2332150-18-peter.maydell@linaro.org
In the A64 decoder, use FPST_A64 rather than FPST_FPCR. By
doing an automated conversion of the whole file we avoid possibly
using more than one fpst value in a set_rmode/op/restore_rmode
sequence.
Patch created with
perl -p -i -e 's/FPST_FPCR(?!_)/FPST_A64/g' target/arm/tcg/translate-{a64,sve,sme}.c
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250124162836.2332150-12-peter.maydell@linaro.org
Do not reference TCG_TARGET_HAS_* directly.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The DSB nXS variant is always both a reads and writes request type.
Ignore the domain field like we do in plain DSB and perform a full
system barrier operation.
The DSB nXS variant is part of FEAT_XS made mandatory from Armv8.7.
Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241211144440.2700268-5-peter.maydell@linaro.org
[PMM: added missing "UNDEF unless feature present" check]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Pass float_status not env to match other functions.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20241206031952.78776-3-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Pass float_status not env to match other functions.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20241206031952.78776-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Remove lookup_disas_fn, handle_2misc_widening,
disas_simd_two_reg_misc, disas_data_proc_simd,
disas_data_proc_simd_fp, disas_a64_legacy, as
this is the final insn to be converted.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241211163036.2297116-70-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Remove handle_2misc_reciprocal as these were the last
insns decoded by that function.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241211163036.2297116-69-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Remove disas_simd_scalar_two_reg_misc and
disas_simd_two_reg_misc_fp16 as these were the
last insns decoded by those functions.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241211163036.2297116-67-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This includes FCMEQ, FCMGT, FCMGE, FCMLT, FCMLE.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241211163036.2297116-66-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Remove handle_2misc_64 as these were the last insns decoded
by that function. Remove helper_advsimd_f16to[su]inth as unused;
we now always go through helper_vfp_to[su]hh or a specialized
vector function instead.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241211163036.2297116-65-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Remove handle_simd_shift_fpint_conv and disas_simd_shift_imm
as these were the last insns decoded by those functions.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241211163036.2297116-64-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Remove handle_simd_intfp_conv and handle_simd_shift_intfp_conv
as these were the last insns decoded by those functions.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241211163036.2297116-63-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Remove disas_simd_scalar_shift_imm as these were the
last insns decoded by that function.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241211163036.2297116-61-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
