Commit graph

17 commits

Author SHA1 Message Date
Thomas Huth b2f1326437
Move target-* CPU file into a target/ folder
We've currently got 18 architectures in QEMU, and thus 18 target-xxx
folders in the root folder of the QEMU source tree. More architectures
(e.g. RISC-V, AVR) are likely to be included soon, too, so the main
folder of the QEMU sources slowly gets quite overcrowded with the
target-xxx folders.
To disburden the main folder a little bit, let's move the target-xxx
folders into a dedicated target/ folder, so that target-xxx/ simply
becomes target/xxx/ instead.

Backports commit fcf5ef2ab52c621a4617ebbef36bf43b4003f4c0 from qemu
2018-03-01 22:50:58 -05:00
Richard Henderson cf9424d60d
target-m68k: Inline shifts
Also manage word and byte operands and fix the computation of
overflow in the case of M68000 arithmetic shifts.

Backports commit 367790cce8e14131426f5190dfd7d1bdbf656e4d from qemu
2018-03-01 12:11:10 -05:00
Laurent Vivier 3558b93f11
target-m68k: introduce byte and word cc_ops
Backports commit db3d7945ae7992c91cc5705dccf60fec79b24dc4 from qemu
2018-02-28 06:52:16 -05:00
Richard Henderson 549e31cc72
target-m68k: Inline addx, subx, negx
And add opcodes for 680x0

Backports commit a665a820e5d46b1611f409fbc7a540fe1c6bf5c8 from qemu
2018-02-28 01:02:31 -05:00
Richard Henderson 121309a4d0
target-m68k: Reorg flags handling
Separate all ccr bits. Continue to batch updates via cc_op.

Signed-off-by: Richard Henderson <rth@twiddle.net>

Fix gen_logic_cc() to really extend the size of the result.
Fix gen_get_ccr(): update cc_op as it is used by the helper.
Factorize flags computing and src/ccr cleanup

Backports commit 620c6cf66584bfbee90db84a7e87a6eabf230ca9 from qemu
2018-02-27 09:30:32 -05:00
Richard Henderson 61ab9a42cd
target-m68k: Remove incorrect clearing of cc_x
The CF docs certainly doesnt suggest this is true.

Backports commit 18dd87f26bed46f22bb1b9536329c02de500f407 from qemu
2018-02-27 09:21:26 -05:00
Richard Henderson 187c2a9807
target-m68k: Some fixes to SR and flags management
Backports commit 99c514485b1d7922c4ca1ed767fd45525de4701f from qemu
2018-02-27 09:19:21 -05:00
Richard Henderson 9493b29399
target-m68k: Print flags properly
Backports commit 8e394ccabdb1e439aab092de6b9d2f26432e962f from qemu
2018-02-27 09:17:44 -05:00
Laurent Vivier 125675e334
target-m68k: don't update cc_dest in helpers
Backports commit 91f90d7191f862ab27528dbdf76cee55c77f79cf from qemu
2018-02-27 09:04:51 -05:00
Laurent Vivier b8366d5b31
target-m68k: remove m68k_cpu_exec_enter() and m68k_cpu_exec_exit()
Update cc_op directly from tcg_gen_insn_start() and
restore_state_to_opc()

Copied from target-i386

Backports commit 20a8856eba0980fbe9d2b8ed2b33ecdb9c9fe5ad from qemu
2018-02-27 08:53:02 -05:00
Laurent Vivier a521f4f41d
target-m68k: Replace helper_xflag_lt with setcond
Backports commit f9083519034aaa5ad5cd2c5727bd61c29bf60bc5 from qemu
2018-02-27 08:50:44 -05:00
Laurent Vivier b079255576
target-m68k: allow to update flags with operation on words and bytes
Backports commit 5dbb6784b7e2b833c036b4df58aa07067e35f476 from qemu
2018-02-27 08:47:12 -05:00
Paolo Bonzini 57fff7a94b
target-m68k: fix get_mac_extf helper
val is assigned twice; the second one should be combined with "|".
Reported by Coverity.

Backports commit 5ce747cfac697f61668ab4fa4a71c1dba15cc272 from qemu
2018-02-25 23:21:05 -05:00
Aleksandar Markovic 6eb4fa54f6
softfloat: Implement run-time-configurable meaning of signaling NaN bit
This patch modifies SoftFloat library so that it can be configured in
run-time in relation to the meaning of signaling NaN bit, while, at the
same time, strictly preserving its behavior on all existing platforms.

Background:

In floating-point calculations, there is a need for denoting undefined or
unrepresentable values. This is achieved by defining certain floating-point
numerical values to be NaNs (which stands for "not a number"). For additional
reasons, virtually all modern floating-point unit implementations use two
kinds of NaNs: quiet and signaling. The binary representations of these two
kinds of NaNs, as a rule, differ only in one bit (that bit is, traditionally,
the first bit of mantissa).

Up to 2008, standards for floating-point did not specify all details about
binary representation of NaNs. More specifically, the meaning of the bit
that is used for distinguishing between signaling and quiet NaNs was not
strictly prescribed. (IEEE 754-2008 was the first floating-point standard
that defined that meaning clearly, see [1], p. 35) As a result, different
platforms took different approaches, and that presented considerable
challenge for multi-platform emulators like QEMU.

Mips platform represents the most complex case among QEMU-supported
platforms regarding signaling NaN bit. Up to the Release 6 of Mips
architecture, "1" in signaling NaN bit denoted signaling NaN, which is
opposite to IEEE 754-2008 standard. From Release 6 on, Mips architecture
adopted IEEE standard prescription, and "0" denotes signaling NaN. On top of
that, Mips architecture for SIMD (also known as MSA, or vector instructions)
also specifies signaling bit in accordance to IEEE standard. MSA unit can be
implemented with both pre-Release 6 and Release 6 main processor units.

QEMU uses SoftFloat library to implement various floating-point-related
instructions on all platforms. The current QEMU implementation allows for
defining meaning of signaling NaN bit during build time, and is implemented
via preprocessor macro called SNAN_BIT_IS_ONE.

On the other hand, the change in this patch enables SoftFloat library to be
configured in run-time. This configuration is meant to occur during CPU
initialization, at the moment when it is definitely known what desired
behavior for particular CPU (or any additional FPUs) is.

The change is implemented so that it is consistent with existing
implementation of similar cases. This means that structure float_status is
used for passing the information about desired signaling NaN bit on each
invocation of SoftFloat functions. The additional field in float_status is
called snan_bit_is_one, which supersedes macro SNAN_BIT_IS_ONE.

IMPORTANT:

This change is not meant to create any change in emulator behavior or
functionality on any platform. It just provides the means for SoftFloat
library to be used in a more flexible way - in other words, it will just
prepare SoftFloat library for usage related to Mips platform and its
specifics regarding signaling bit meaning, which is done in some of
subsequent patches from this series.

Further break down of changes:

1) Added field snan_bit_is_one to the structure float_status, and
correspondent setter function set_snan_bit_is_one().

2) Constants <float16|float32|float64|floatx80|float128>_default_nan
(used both internally and externally) converted to functions
<float16|float32|float64|floatx80|float128>_default_nan(float_status*).
This is necessary since they are dependent on signaling bit meaning.
At the same time, for the sake of code cleanup and simplicity, constants
<floatx80|float128>_default_nan_<low|high> (used only internally within
SoftFloat library) are removed, as not needed.

3) Added a float_status* argument to SoftFloat library functions
XXX_is_quiet_nan(XXX a_), XXX_is_signaling_nan(XXX a_),
XXX_maybe_silence_nan(XXX a_). This argument must be present in
order to enable correct invocation of new version of functions
XXX_default_nan(). (XXX is <float16|float32|float64|floatx80|float128>
here)

4) Updated code for all platforms to reflect changes in SoftFloat library.
This change is twofolds: it includes modifications of SoftFloat library
functions invocations, and an addition of invocation of function
set_snan_bit_is_one() during CPU initialization, with arguments that
are appropriate for each particular platform. It was established that
all platforms zero their main CPU data structures, so snan_bit_is_one(0)
in appropriate places is not added, as it is not needed.

[1] "IEEE Standard for Floating-Point Arithmetic",
IEEE Computer Society, August 29, 2008.

Backports commit af39bc8c49224771ec0d38f1b693ea78e221d7bc from qemu
2018-02-24 20:27:12 -05:00
Paolo Bonzini 9485b7c2e1
cpu: move exec-all.h inclusion out of cpu.h
exec-all.h contains TCG-specific definitions. It is not needed outside
TCG-specific files such as translate.c, exec.c or *helper.c.

One generic function had snuck into include/exec/exec-all.h; move it to
include/qom/cpu.h.

Backports commit 63c915526d6a54a95919ebece83fa9ca631b2508 from qemu
2018-02-24 02:39:08 -05:00
Peter Maydell 79ca0b299a
m68k: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Backports commit d8416665774bb6c057cbb3dd67d802e67e7a03ef from qemu
2018-02-19 01:06:05 -05:00
Nguyen Anh Quynh 344d016104 import 2015-08-21 15:04:50 +08:00