Fix two bugs in the translation of the instructions VMOV sa,sb,rx,ry and
VMOV rx,ry,sa,sb (which copy between a pair of ARM core registers and a
pair of VFP single precision registers):

 * An incorrect condition meant these instruction patterns were being
   treated as load/store multiple, which resulted in the generation
   of bad code and a runtime segfault
 * The order of the core register pair was reversed so the values would
   go to the wrong registers
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

In v7 of the ARM architecture, WFI (wait for interrupt) is a first-class
instruction, but in previous versions this functionality was provided
via a cp15 coprocessor register. Add correct feature checks to the
decoding of the cp15 WFI instructions so that they behave correctly
for newer cores. In particular, the old 0,c7,c8,2 encoding used on
ARM940 has been reused for VA-to-PA translation in v6 and v7.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAdam Lackorzynski <adam@os.inf.tu-dresden.de>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

For Neon shifts by immediate and narrow, correctly handle the case
where the source registers and the destination registers overlap
(the second pass should use the original register contents, not the
results of the first pass).

This includes a refactoring to pull the size check outside the
loop rather than inside, since there is now very little common
code between the size == 3 and size != 3 case.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Pull the code which decodes narrowing operations as being either
signed/unsigned saturate or plain out into its own function.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Fix decoding of 64 bits variants of VSHRN, VRSHRN, VQSHRN, VQSHRUN,
VQRSHRN, VQRSHRUN, taking into account whether inputs are unsigned
or not.
Signed-off-by: NChristophe Lyon <christophe.lyon@st.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Call the normal shift helpers instead of the rounding ones.
Signed-off-by: NChristophe Lyon <christophe.lyon@st.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Move the implementation of the Neon VUZP unzip instruction from inline
code to helper functions. (At 50+ TCG ops it was well over the
recommended limit for coding inline.) The helper implementations also
give the correct answers where the inline implementation did not.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Move the implementation of the Neon VUZP unzip instruction from inline
code to helper functions. (At 50+ TCG ops it was well over the
recommended limit for coding inline.) The helper implementations also
fix the handling of the quadword version of the instruction.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

We handle Thumb Neon data processing instructions by converting them
into the equivalent ARM encoding, as the two are very close. However
the ARM encoding should have bit 28 set, not clear. This wasn't causing
any problems because we don't actually look at that bit during decode;
however it is better to do the conversion correctly to avoid problems
later if we add checks to UNDEF on SBZ/SBO bits.
Signed-off-by: NJuha Riihimäki <juha.riihimaki@nokia.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

For VQDMLSL, negation has to occur after saturation, not before.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Refactor the handling of VQDMULL so that it is dealt with in
its own if() case rather than together with the accumulating
instructions.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Implement VMULL.P8 (the 32x32->64 version of the polynomial multiply
instruction).
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

The Neon half-precision conversion operations (VCVT.F16.F32 and
VCVT.F32.F16) use ARM standard floating-point arithmetic, unlike
the VFP versions (VCVTB and VCVTT).
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Signed-off-by: NChristophe Lyon <christophe.lyon@st.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Fix bit mask used when widening the result of shift on narrow input.
Signed-off-by: NChristophe Lyon <christophe.lyon@st.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

VQMOVUN does a signed-to-unsigned saturating conversion. This is
different from both the signed-to-signed and unsigned-to-unsigned
conversions already implemented, so we need a new set of helper
functions (neon_unarrow_sat*).
Signed-off-by: NJuha Riihimäki <juha.riihimaki@nokia.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Refine the decoding of the Thumb preload and hint space, so we
UNDEF on the patterns that are supposed to UNDEF rather than NOP.
We also move the tests for this space earlier, so we don't emit
harmless but unnecessary address generation code for preload
hints (which by their nature are likely to be in hot code paths).
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Correct the decoding of the ARM preload and memory hint space,
by adding decoding of PLI, PLDW and the v7MP unallocated hint
space. This commit also corrects a slightly overexuberant
decoding of PLD(register) which was not checking that bit 4
was one.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Signed-off-by: NChristophe Lyon <christophe.lyon@st.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

This patch fixes the errors reported by my tests in VSRA.
Signed-off-by: NChristophe Lyon <christophe.lyon@st.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Fix the register and part of register we get the scalar from in
the various "multiply vector by scalar" ops (VMUL by scalar
and friends).
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Fix garbage collection of temporaries in Neon emulation.
Signed-off-by: NChristophe Lyon <christophe.lyon@st.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

This patch fixes corner-case saturations, when the target range is
zero. It merely removes the guard against (sh == 0), and makes:
__ssat(0x87654321, 1) return 0xffffffff and set the saturation flag
__usat(0x87654321, 0) return 0 and set the saturation flag
Signed-off-by: NChristophe Lyon <christophe.lyon@st.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Add support for logging the start of instructions in TCG
code debug dumps for ARM targets.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NEdgar E. Iglesias <edgar.iglesias@gmail.com>

We were not correctly restoring the IT bits when resuming execution
after taking an unexpected exception in the middle of an IT block.
Fix this by tracking them along with PC changes and restoring in
gen_pc_load().

This fixes bug https://bugs.launchpad.net/qemu/+bug/581335Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Create a new function which does the common sequence of gen_set_condexec,
gen_set_pc_im, gen_exception, set is_jmp to DISAS_JUMP.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Remove a redundant call to gen_set_condexec() in the translation of Thumb
mode SWI. (SWI and WFI generate "exceptions" which happen after the
execution of the instruction, ie when PC and IT bits have updated.
So the condexec bits at this point are not correct. However, the code
that handles finishing the translation of the TB will write the correct
value of the condexec bits later, so the only effect was that a conditional
Thumb SWI would generate slightly worse code than necessary.)
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

When translating, get the user/priv state from the TB flags, not
the CPUState.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

When translating, the condexec bits for the TB are in the TB flags;
the CPUState condexec bits may be different.

This patch fixes https://bugs.launchpad.net/bugs/604872 where we might
segfault if we took an exception in the middle of a TB with an IT
block, because when we came to retranslate in cpu_restore_state()
the CPUState condexec bits would have advanced compared to the start
of the TB and we would generate different (wrong) code.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

The Thumb/ARM state for the TB being translated should come from
the TB flags, not the CPUState.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

When translating, the VFP vector length and stride for this TB are encoded
in the TB flags; the CPUState copies may be different and must not be used.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

When translating code, whether the VFP unit is enabled for this TB
is stored in a bit in the TB flags. Use this rather than incorrectly
reading the FPEXC from the CPUState passed to translation.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

When translating the SRS instruction, handle the "store registers
to stack of current mode" case in the helper function rather than
inline. This means the generated code does not make assumptions
about the current CPU mode which might not be valid when the TB
is executed later.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Fix errors in the decoding of ARM VQSHL/VQSHLU immediate forms,
including using the new VQSHLU helper functions where appropriate.
Reviewed-by: NAurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

SMMLA and SMMLS are broken on both in normal and thumb mode, that is
both (different) implementations are wrong. They try to avoid a 64-bit
add for the rounding, which is not trivial if you want to support both
SMMLA and SMMLS with the same code.

The code below uses the same implementation for both modes, using the
code from the ARM manual. It also fixes the thumb decoding that was a
mix between normal and thumb mode.

This fixes the issues reported in
https://bugs.launchpad.net/qemu/+bug/629298Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

UMAAL should use unsigned multiply instead of signed.

This patch fixes this issue by handling UMAAL separately from
UMULL/UMLAL/SMULL/SMLAL as these instructions are different
enough. It also explicitly list instructions in case and catch
nonexistent instruction as illegal. Also fixes a few style issues.

This fixes the issues reported in
https://bugs.launchpad.net/qemu/+bug/696015Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Correct the arguments passed when generating neon qshl_{u,s}64()
helpers so that we use the correct registers.
Signed-off-by: NJuha Riihimäki <juha.riihimaki@nokia.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

The translation of REVSH shifted the low byte 8 steps left before performing
an 8-bit sign extend, causing this part of the expression to alwas be 0.
Reported-by: NJohan Bengtsson <teofrastius@gmail.com>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NNathan Froyd <froydnj@codesourcery.com>

Fix errors in the decoding of the Neon forms of fixed-point VCVT:
 * fixed-point VCVT is op 14 and 15, not 15 and 16
 * the fbits immediate field was being misinterpreted
 * the sense of the to_fixed bit was inverted
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NNathan Froyd <froydnj@codesourcery.com>