Commit Graph

465 Commits

Author SHA1 Message Date
Peter Maydell
25f84f7948 target-arm: Handle UNDEF cases for Neon 3-regs-same insns
Correct the handling of UNDEF cases for the NEON "3 registers same
size" forms, by adding missing checks and rationalising some others
so they are done early enough to avoid leaking TCG temporaries.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-04-12 21:51:51 +02:00
Peter Maydell
62698be3ba target-arm: Use lookup table for size check on Neon 3-reg-same insns
Simplify the checks for invalid size values for the Neon "three registers
of the same size" instruction forms (and add them where they were missing)
by using a lookup table.

This includes adding symbolic constants for the op values in this space,
since we now use them in multiple places.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-04-12 21:51:51 +02:00
Dmitry Eremin-Solenikov
be5e7a7601 arm: basic support for ARMv4/ARMv4T emulation
Currently target-arm/ assumes at least ARMv5 core. Add support for
handling also ARMv4/ARMv4T. This changes the following instructions:

BX(v4T and later)

BKPT, BLX, CDP2, CLZ, LDC2, LDRD, MCRR, MCRR2, MRRC, MCRR, MRC2, MRRC,
MRRC2, PLD QADD, QDADD, QDSUB, QSUB, STRD, SMLAxy, SMLALxy, SMLAWxy,
SMULxy, SMULWxy, STC2 (v5 and later)

All instructions that are "v5TE and later" are also bound to just v5, as
that's how it was before.

This patch doesn _not_ include disabling of cp15 access and base-updated
data abort model (that will be required to emulate chips based on a
ARM7TDMI), because:
* no ARM7TDMI chips are currently emulated (or planned)
* those features aren't strictly necessary for my purposes (SA-1 core
  emulation).

All v5 models are handled as they are v5T. Internally we still have a
check if the model is a v5(T) or v5TE, but as all emulated cores are
v5TE, those two cases are simply aliased (for now).

Patch is heavily based on patch by Filip Navara <filip.navara@gmail.com>
which in turn is based on work by Ulrich Hecht <uli@suse.de> and Vincent
Sanders <vince@kyllikki.org>.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-04-10 00:53:21 +02:00
Stefan Weil
4b4a72e556 Fix conversions from pointer to tcg_target_long
tcg_gen_exit_tb takes a parameter of type tcg_target_long,
so the type casts of pointer to long should be replaced by
type casts of pointer to tcg_target_long (suggested by Blue Swirl).

These changes are needed for build environments where
sizeof(long) != sizeof(void *), especially for w64.

Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-04-10 00:45:16 +02:00
Peter Maydell
cc49f21780 target-arm: Make Neon helper routines use correct FP status
Make the Neon helper routines use the correct FP status from
the CPUEnv rather than using a dummy static one. This means
they will correctly handle denormals and NaNs and will set
FPSCR exception bits properly.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-04-04 20:18:07 +02:00
Peter Maydell
947a2fa21b target-arm: Use global env in iwmmxt_helper.c helpers
Use the global 'env' variable in the helper functions in iwmmxt_helper.c.
This means we don't need to pass env as an argument to them any more.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-04-04 20:18:07 +02:00
Peter Maydell
2a3f75b42a target-arm: Use global env in neon_helper.c helpers
Use the global 'env' variable in the helper functions in neon_helper.c.
This means we don't need to pass env as an argument to them any more.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-04-04 20:18:06 +02:00
Peter Maydell
622465e1fa target-arm/helper.c: For float-int conversion helpers pass ints as ints
Correct the argument and return types for the float<->int conversion helper
functions so that integer arguments and return values are declared as
uint32_t/uint64_t, not float32/float64. This allows us to remove the
hand-rolled functions which were doing bitwise copies between the types
via unions.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Nathan Froyd <froydnj@codesourcery.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-04-03 17:19:38 +02:00
Peter Maydell
4a9f9cb24d target-arm: Use new softfloat min/max functions for VMAX, VMIN
Use the new softfloat min/max functions to implement the Neon VMAX
and VMIN instructions. This allows us to get the right behaviour
for NaN and negative zero.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-04-03 17:19:38 +02:00
Peter Maydell
79c18be7df target-arm: Correct ABD's handling of negative zeroes
Implement ABD by taking the absolute value of the difference
of the operands (as the ARM ARM specifies) rather than by
flipping the order of the operands to the subtract based
on the results of a comparison. The latter approch gives
the wrong answers for some edge cases like negative zero.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-04-03 17:19:38 +02:00
Peter Maydell
0e3261098f target-arm: Fix VCLE.F32 #0, VCLT.F32 #0 NaN handling
Implementing the floating-point versions of VCLE #0 and VCLT #0 by
doing a GT comparison and inverting the result gives the wrong
result if the input is a NaN. Implement as a GT comparison with the
operands swapped instead.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-04-03 17:19:38 +02:00
Peter Maydell
c7498daea7 target-arm: Return right result for Neon comparison with NaNs
Fix the helper functions implementing the Neon floating point comparison
ops (VCGE, VCGT, VCEQ, VACGT, VACGE) to return the right answer when
one of the values being compared is a NaN.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-04-03 17:05:43 +02:00
Peter Maydell
51d852672c target-arm/neon_helper.c: Use make_float32/float32_val macros
Use the softfloat make_float32 and float32_val macros to convert between
softfloat's float32 type and raw uint32_t types, rather than private
conversion functions.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Nathan Froyd <froydnj@codesourcery.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-04-03 17:04:13 +02:00
Peter Maydell
e318a60b94 target-arm: Don't leak TCG temp for UNDEFs in Neon load/store space
Move the allocation and freeing of the TCG temp used for the address for
Neon load/store instructions so that we don't allocate the temporary
until we've done enough decoding to know that the instruction is not
an UNDEF pattern; this avoids leaking the TCG temp in these cases.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-04-01 22:33:47 +02:00
Peter Maydell
8e18cde30b target-arm: Fix VLD of single element to all lanes
Fix several bugs in VLD of single element to all lanes:

The "single element to all lanes" form of VLD1 differs from those for
VLD2, VLD3 and VLD4 in that bit 5 indicates whether the loaded element
should be written to one or two Dregs (rather than being a register
stride). Handle this by special-casing VLD1 rather than trying to
have one loop which deals with both VLD1 and 2/3/4.

Handle VLD4.32 with 16 byte alignment specified, rather than UNDEFfing.

UNDEF for the invalid size and alignment combinations.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-04-01 22:33:47 +02:00
Peter Maydell
6aae3df15d target-arm: use make_float32() to make constant floats for VRSQRTS
The preferred way to create a constant floating point value is to use
make_float32() rather than doing a runtime int32_to_float32().
Convert the code in the VRSQRTS helper to work this way.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-03-22 07:59:07 +01:00
Peter Maydell
dda3ec490c target-arm: Fix VRECPS edge cases handling
Correct the handling of edge cases for the VRECPS instruction:
 * this is a Neon instruction so uses the "standard FPSCR value"
 * (zero, inf) is a special case which returns 2.0

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-03-22 07:59:06 +01:00
Peter Maydell
7d2aabe262 target-arm: Fix TCG temporary leaks for scalar VMULL
Fix a TCG temporary leak when translating 32-bit scalar VMULL.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-03-22 07:56:30 +01:00
Peter Maydell
e1d177b922 target-arm: Set Q bit for overflow in SMUAD and SMLAD
SMUAD and SMLAD are supposed to set the Q bit if the addition of
the two 16x16 multiply products and optional accumulator overflows
considered as a signed value. However we were only doing this check
for the addition of the accumulator, not when adding the products,
with the effect that we were mishandling the edge case where
both inputs are 0x80008000.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-03-22 07:56:08 +01:00
Peter Maydell
db6e2e65ad target-arm: Fix GE bits for v6media signed modulo arithmetic
Fix the signed modulo arithmetic helpers for the v6media
instructions (SADD8, SSUB8, SADD16, SSUB16, SASX, SSAX) to set
the GE bits correctly (based on the result of the add or subtract
before it is truncated to 16 bits, not after).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-03-22 07:52:36 +01:00
Peter Maydell
2a0308c54f target-arm: Fix UNDEF cases in Thumb load/store
Decode of Thumb load/store was merging together the cases of 'bit 11==0'
(reg+reg LSL imm) and 'bit 11==1' (reg+imm). This happens to work for
valid instruction patterns but meant that we would not UNDEF for the
cases the architecture mandates that we must. Make the decode actually
look at bit 11 as well as [10..8] so that we UNDEF in the right places.

This change also removes what was a spurious unreachable 'case 8',
and correctly frees TCG temporaries on the illegal-insn codepaths.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-03-22 07:52:35 +01:00
Paolo Bonzini
eda48c344f inline cpu_halted into sole caller
All implementations are now the same, and there is only one caller,
so inline the function there.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2011-03-13 14:44:21 +00:00
Peter Maydell
ca27c052d9 target-arm: Implement a minimal set of cp14 debug registers
Newer ARM kernels try to probe for whether the CPU has hardware breakpoint
support. For this to work QEMU has to implement a minimal set of the cp14
debug registers. The architecture requires v7 cores to implement debug
and so there is no defined way to report its absence; however in practice
returning a zero DBGDIDR (ie with a reserved value for "debug architecture
version") should cause well-written hw debug users to do the right thing.
We also implement DBGDRAR and DBGDSAR as RAZ, indicating no memory mapped
debug components.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-03-07 09:46:19 +01:00
Peter Maydell
3849902cd8 target-arm: Use TCG temporary leak debugging facilities
Use the new TCG temporary leak debugging facilities to
check that each ARM instruction does not leak temporaries.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-03-07 09:26:18 +01:00
Peter Maydell
7d1b0095bf target-arm: Remove ad-hoc leak checking code
This commit removes the ad-hoc resource leak checking code from
target-arm. This includes replacing all uses of new_tmp() with
tcg_temp_new_i32() and all uses of dead_tmp() with
tcg_temp_free_i32().

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-03-07 09:26:10 +01:00
Adam Lackorzynski
f8bf860605 target-arm: Implement cp15 VA->PA translation
Implement VA->PA translations by cp15-c7 that went through unchanged
previously.

Signed-off-by: Adam Lackorzynski <adam@os.inf.tu-dresden.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-03-06 23:37:18 +01:00
Peter Maydell
29501f1b9e target-arm: Set carry flag correctly for Thumb2 ORNS
The code for Thumb2 ORNS (or negated and set flags) was trashing
a TCG input register which was needed later for use in calculating
flags, with the effect that the carry flag was always set with
the wrong sense. Fix this by using the TCG orc op instead of
separate not and or ops.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-03-06 23:30:18 +01:00
Peter Maydell
8387da8197 target-arm: Handle VMOV between two core and VFP single regs
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: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-03-06 20:28:08 +01:00
Peter Maydell
cc68890166 target-arm: Don't decode old cp15 WFI instructions on v7 cores
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: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Adam Lackorzynski <adam@os.inf.tu-dresden.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-03-06 20:20:19 +01:00
Christophe Lyon
e07be5d2ae target-arm: fix support for VRSQRTE.
Now use the same algorithm as described in the ARM ARM.

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-24 08:53:36 +01:00
Christophe Lyon
fe0e4872e4 target-arm: fix support for VRECPE.
Now use the same algorithm as described in the ARM ARM.

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-24 08:53:36 +01:00
Christophe Lyon
56bf4fe297 target-arm: Introduce float64_256 and float64_512 constants.
These two constants will be used by helper functions such as recpe_f32
and rsqrte_f32.

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-24 08:53:36 +01:00
Peter Maydell
92cdfaeb61 target-arm: Fix shift by immediate and narrow where src, dest overlap
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: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-21 15:39:03 +01:00
Peter Maydell
c33171c7f2 target-arm: Refactor to pull narrowing decode into separate function
Pull the code which decodes narrowing operations as being either
signed/unsigned saturate or plain out into its own function.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-21 15:39:02 +01:00
Peter Maydell
33ebc29337 target-arm: Fix unsigned VQRSHL by large shift counts
Correctly handle VQRSHL of unsigned values by a shift count of the
width of the data type or larger, which must be special-cased in the
qrshl_u* helper functions.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-20 17:43:01 +01:00
Peter Maydell
7b6ecf5b3a target-arm: Fix signed VQRSHL by large shift counts
Handle the case of signed VQRSHL by a shift count of the width of the
data type or larger, which must be special cased in the qrshl_s*
helper functions.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-20 17:43:01 +01:00
Christophe Lyon
0b36f4cd47 target-arm: fix decoding of Neon 64 bit shifts.
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: Christophe Lyon <christophe.lyon@st.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-20 17:43:01 +01:00
Christophe Lyon
b408a9b072 target-arm: fix Neon VQSHRN and VSHRN.
Call the normal shift helpers instead of the rounding ones.

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-20 17:43:01 +01:00
Peter Maydell
960e623bfd target-arm: Fix saturated values for Neon right shifts
Fix value returned by signed 8 and 16 bit qrshl helpers
when the result has saturated.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-20 17:43:01 +01:00
Christophe Lyon
51e3930fc7 target-arm: fix unsigned 64 bit right shifts.
Fix range of shift amounts which always give 0 as result.

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-20 17:43:01 +01:00
Christophe Lyon
b6c63b9891 target-arm: Fix unsigned VRSHL.s8 and .s16 right shifts by type width
Fix handling of unsigned VRSHL.s8 and .s16 right shifts by the type
width.

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-20 17:43:01 +01:00
Peter Maydell
0670a7b65b target-arm: Fix signed VRSHL by large shift counts
Correctly handle VRSHL of signed values by a shift count of the
width of the data type or larger, which must be special-cased in the
rshl_s* helper functions.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-20 17:43:01 +01:00
Christophe Lyon
4bd4ee072c target-arm: Fix rounding constant addition for Neon shifts
Handle cases where adding the rounding constant could overflow in Neon
shift instructions: VRSHR, VRSRA, VQRSHRN, VQRSHRUN, VRSHRN.

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
[peter.maydell@linaro.org: fix handling of large shifts in rshl_s32,
calculate signed saturated value as other functions do.]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-20 17:43:01 +01:00
Peter Maydell
d68a6f3a6d target-arm: Move Neon VZIP to helper functions
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: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-20 17:31:53 +01:00
Peter Maydell
02acedf93d target-arm: Move Neon VUZP to helper functions
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: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-20 17:31:52 +01:00
Juha Riihimäki
f06053e3c3 target-arm: Correct conversion of Thumb Neon dp encodings into ARM
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: Juha Riihimäki <juha.riihimaki@nokia.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-20 17:30:09 +01:00
Peter Maydell
4dc064e66e target-arm: Fix Neon VQDMLSL instruction
For VQDMLSL, negation has to occur after saturation, not before.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-20 17:28:39 +01:00
Peter Maydell
ebcd88ceb5 target-arm: Refactor handling of VQDMULL
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: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-20 17:28:37 +01:00
Peter Maydell
e5ca24cba9 target-arm: Implement VMULL.P8
Implement VMULL.P8 (the 32x32->64 version of the polynomial multiply
instruction).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-20 17:26:15 +01:00
Dmitry Eremin-Solenikov
3213883efa arm: drop unused irq-related part of CPUARMState
These two fields were added as a part of ARMv7 support patch (back in
2007), were never used by any code, so can be dropped.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andrzej Zaborowski <andrew.zaborowski@intel.com>
2011-02-11 01:10:13 +01:00
Peter Maydell
f2f27b9f9b target-arm: Remove stray #include from middle of neon_helper.c
Remove a stray #include <stdio.h> from the middle of neon_helper.c:
it was harmless but pointless since we include stdio.h at the top
of the file anyway.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-10 21:21:30 +01:00
Peter Maydell
2d981da77d target-arm: Use standard FPSCR for Neon half-precision operations
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: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-10 18:28:30 +01:00
Peter Maydell
fb91678d2c target-arm: Silence NaNs resulting from half-precision conversions
Silence the NaNs that may result from half-precision conversion,
as we do for the other conversions.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-10 18:28:30 +01:00
Peter Maydell
bb4d4bb376 softfloat: Add float16 type and float16 NaN handling functions
Add a float16 type to softfloat, rather than using bits16 directly.
Also add the missing functions float16_is_quiet_nan(),
float16_is_signaling_nan() and float16_maybe_silence_nan(),
which are needed for the float16 conversion routines.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-10 18:28:09 +01:00
Christophe Lyon
923e65097d target-arm: implement vsli.64, vsri.64
Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-09 19:48:48 +01:00
Christophe Lyon
acdf01effa target-arm: fix VSHLL Neon instruction.
Fix bit mask used when widening the result of shift on narrow input.

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-09 19:47:20 +01:00
Peter Maydell
cc2212c2f8 target-arm: Fix 32 bit signed saturating narrow
The returned value when doing saturating signed 64->32 bit
conversion of a negative number was incorrect due to a missing cast.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-09 19:37:48 +01:00
Juha Riihimäki
af1bbf30c4 target-arm: Fix VQMOVUN Neon instruction.
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: Juha Riihimäki <juha.riihimaki@nokia.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-09 19:37:47 +01:00
Peter Maydell
a2fdc8907b target-arm: Fix decoding of Thumb preload and hint space
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: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-04 21:30:15 +01:00
Peter Maydell
3d185e5dd4 target-arm: Fix decoding of preload and memory hint space
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: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-04 21:30:15 +01:00
Peter Maydell
607b4b0876 target-arm: Clean up handling of MPIDR
The ARM cp15 register 0,c0,c0,5 is standardised in the v7 architecture
as the MPIDR. Clean up its implementation to remove A9 specific handling.

This commit includes fixing an error in the value returned for the
MPIDR on A9, where we were erroneously claiming a cluster ID of 9.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-04 21:30:15 +01:00
Peter Maydell
e1bbf44636 target-arm: Add CPU feature flag for v7MP
Add a CPU feature flag for v7MP (the multiprocessing extensions); some
instructions exist only for v7MP and not for the base v7 architecture.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-04 21:30:14 +01:00
Christophe Lyon
72902672dc Set the right overflow bit for neon 32 and 64 bit saturating add/sub.
Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-04 20:57:41 +01:00
Christophe Lyon
5371cb8140 target-arm: Fix Neon vsra instructions.
This patch fixes the errors reported by my tests in VSRA.

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-02-04 20:48:41 +01:00
Juha Riihimäki
46eece9d89 target-arm: Fix Neon VQ(R)DMULH.S16 instructions
Correct an error in the implementation of the 16 bit
forms of VQ(R)DMULH, bringing them into line with the
32 bit implementation.

Signed-off-by: Juha Riihimäki <juha.riihimaki@nokia.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-29 15:16:29 +01:00
Peter Maydell
0fad6efce5 target-arm: Fix loading of scalar value for Neon multiply-by-scalar
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: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-26 14:30:24 +01:00
Christophe Lyon
c6067f04c5 target-arm: Fix garbage collection of temporaries in Neon emulation.
Fix garbage collection of temporaries in Neon emulation.

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-26 14:30:24 +01:00
Christophe Lyon
40d3c43360 Support saturation with shift=0.
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: Christophe Lyon <christophe.lyon@st.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-26 14:30:24 +01:00
Peter Maydell
5642463aee target-arm: Log instruction start in TCG code
Add support for logging the start of instructions in TCG
code debug dumps for ARM targets.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
2011-01-18 15:23:44 +01:00
Peter Maydell
e12ce78d4a target-arm: Restore IT bits when resuming after an exception
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/581335

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-14 20:39:19 +01:00
Peter Maydell
bc4a0de0a2 target-arm: Refactor translation of exception generating instructions
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: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-14 20:39:19 +01:00
Peter Maydell
5de3a9d3b7 target-arm: Remove redundant setting of IT bits before Thumb SWI
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: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-14 20:39:19 +01:00
Peter Maydell
61f74d6a29 target-arm: Translate with user-state from TB flags, not CPUState
When translating, get the user/priv state from the TB flags, not
the CPUState.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-14 20:39:19 +01:00
Peter Maydell
05ed9a9919 target-arm: Set privileged bit in TB flags correctly for M profile
M profile ARM cores don't have a CPSR mode field. Set the bit in the
TB flags that indicates non-user mode correctly for these cores.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-14 20:39:19 +01:00
Peter Maydell
98eac7cab4 target-arm: Translate with condexec bits from TB flags, not CPUState
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: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-14 20:39:19 +01:00
Peter Maydell
7204ab889f target-arm: Translate with Thumb state from TB flags, not CPUState
The Thumb/ARM state for the TB being translated should come from
the TB flags, not the CPUState.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-14 20:39:19 +01:00
Peter Maydell
69d1fc221a target-arm: Translate with VFP len/stride from TB flags, not CPUState
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: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-14 20:39:19 +01:00
Peter Maydell
5df8bac1d3 target-arm: Translate with VFP-enabled from TB flags, not CPUState
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: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-14 20:39:19 +01:00
Peter Maydell
a170576856 target-arm: Add symbolic constants for bitfields in TB flags
Add symbolic constants for the bitfields we use in the TB flags.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-14 20:39:18 +01:00
Peter Maydell
39ea3d4eaf target-arm: Don't generate code specific to current CPU mode for SRS
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: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-14 20:39:18 +01:00
Peter Maydell
718269667a target-arm: Use the standard FPSCR value for VRSQRTS
VSQRTS always uses the standard FPSCR value as it is a Neon instruction.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-14 20:39:18 +01:00
Peter Maydell
3a492f3a60 target-arm: Add support for 'Standard FPSCR Value' as used by Neon
Add support to the ARM helper routines for a second fp_status value
which should be used for operations which the ARM ARM indicates use
"ARM standard floating-point arithmetic" rather than being controlled
by the rounding/flush/NaN settings in the FPSCR.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-14 20:39:18 +01:00
Peter Maydell
9ea62f571c target-arm: Fix implementation of VRSQRTS
The implementation of the ARM VRSQRTS instruction (which calculates
(3 - op1 * op2) / 2) was missing the division operation. It also
did not handle the special cases of (0,inf) and (inf,0).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-14 20:39:18 +01:00
Peter Maydell
0322b26e2d ARM: Fix decoding of VQSHL/VQSHLU immediate forms
Fix errors in the decoding of ARM VQSHL/VQSHLU immediate forms,
including using the new VQSHLU helper functions where appropriate.

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-12 00:06:06 +01:00
Juha Riihimäki
4ca4502c93 ARM: add neon helpers for VQSHLU
Add neon helper functions to implement VQSHLU, which is a
signed-to-unsigned version of VQSHL available only as an
immediate form.

Signed-off-by: Juha Riihimäki <juha.riihimaki@nokia.com>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-12 00:06:06 +01:00
Peter Maydell
cecd8504b8 target-arm: wire up the softfloat flush_input_to_zero flag
Wire up the new softfloat support for flushing input denormals
to zero on ARM. The FPSCR FZ bit enables flush-to-zero for
both inputs and outputs, but the reporting of when inputs are
flushed to zero is via a separate IDC bit rather than the UFC
(underflow) bit used when output denormals are flushed to zero.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-06 22:16:59 +01:00
Peter Maydell
b12c390b91 target-arm: Set softfloat cumulative exc flags from correct FPSCR bits
When handling a write to the ARM FPSCR, set the softfloat cumulative
exception flags from the cumulative flags in the FPSCR, not the
exception-enable bits. Also don't apply a mask: vfp_exceptbits_to_host
will only look at the correct bits anyway.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-06 22:16:59 +01:00
Aurelien Jarno
838fa72d0b target-arm: fix SMMLA/SMMLS instructions
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/629298

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-01-06 22:16:46 +01:00
Aurelien Jarno
8aac08b10b target-arm: fix UMAAL instruction
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/696015

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2010-12-31 22:22:26 +01:00
Juha Riihimäki
16440c5fa0 target-arm: correct cp15 c1_sys reset value for arm1136 and cortex-a9
Signed-off-by: Juha Riihimäki <juha.riihimaki@nokia.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2010-12-27 21:21:17 +01:00
Mattias Holm
9c486ad6e4 target-arm: correct cp15 c1_sys reset value for cortex-a8
Signed-off-by: Juha Riihimäki <juha.riihimaki@nokia.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2010-12-27 21:21:17 +01:00
Juha Riihimäki
c003432809 target-arm: fix vmsav6 access control
Override access control checks (including execute) for mmu translation
table descriptors assigned to manager domains.

Signed-off-by: Juha Riihimäki <juha.riihimaki@nokia.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2010-12-27 21:21:16 +01:00
Peter Maydell
a5d88f3e03 target-arm: Correct result in saturating cases for VQSHL of s8/16/32
Where VQSHL of a signed 8/16/32 bit value saturated, the result
value was not being calculated correctly (it should be either
the minimum or maximum value for the size of the signed type).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2010-12-27 21:07:24 +01:00
Juha Riihimäki
620d791e34 target-arm: remove pointless else clause in VQSHL of u64
Remove a pointless else clause in the neon_qshl_u64 helper.

Signed-off-by: Juha Riihimäki <juha.riihimaki@nokia.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2010-12-27 21:07:16 +01:00
Peter Maydell
eb7a3d7964 target-arm: Fix VQSHL of signed 64 bit values by shift counts >= 64
VQSHL of a signed 64 bit non-zero value by a shift count >= 64 should
saturate; return the correct value in this case.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2010-12-27 21:07:10 +01:00
Juha Riihimäki
4c9b70aeca target-arm: Fix VQSHL of signed 64 bit values
Add a missing '-' which meant that we were misinterpreting the shift
argument for VQSHL of 64 bit signed values and treating almost every
shift value as if it were an extremely large right shift.

Signed-off-by: Juha Riihimäki <juha.riihimaki@nokia.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2010-12-27 21:07:03 +01:00
Juha Riihimäki
def126ce37 target-arm: Fix arguments passed to VQSHL helpers
Correct the arguments passed when generating neon qshl_{u,s}64()
helpers so that we use the correct registers.

Signed-off-by: Juha Riihimäki <juha.riihimaki@nokia.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2010-12-27 21:06:55 +01:00
Aurelien Jarno
1a855029af target-arm: fix bug in translation of REVSH
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: Johan Bengtsson <teofrastius@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2010-12-27 19:56:43 +01:00
Peter Maydell
72f24d155c ARM: Implement VCVT to 16 bit integer using new softfloat routines
Use the softfloat conversion routines for conversion to 16 bit
integers, because just casting to a 16 bit type truncates the
value rather than saturating it at 16-bit MAXINT/MININT.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Nathan Froyd <froydnj@codesourcery.com>
2010-12-07 15:37:34 +00:00
Peter Maydell
26a5e69aaf ARM: Ignore top 16 bits when doing VCVT from 16 bit fixed point
VCVT of 16 bit fixed point to float should ignore the top 16 bits
of the source register. Cast to int16_t and friends rather than
int16 -- the former is guaranteed exactly 16 bits wide where the
latter is merely at least 16 bits wide (and so is usually 32 bits).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Nathan Froyd <froydnj@codesourcery.com>
2010-12-07 15:37:34 +00:00