Unicorn CPU emulator framework (ARM, AArch64, M68K, Mips, Sparc, X86)
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Emilio G. Cota bca8e39e3c
fpu: introduce hardfloat
The appended paves the way for leveraging the host FPU for a subset
of guest FP operations. For most guest workloads (e.g. FP flags
aren't ever cleared, inexact occurs often and rounding is set to the
default [to nearest]) this will yield sizable performance speedups.

The approach followed here avoids checking the FP exception flags register.
See the added comment for details.

This assumes that QEMU is running on an IEEE754-compliant FPU and
that the rounding is set to the default (to nearest). The
implementation-dependent specifics of the FPU should not matter; things
like tininess detection and snan representation are still dealt with in
soft-fp. However, this approach will break on most hosts if we compile
QEMU with flags that break IEEE compatibility. There is no way to detect
all of these flags at compilation time, but at least we check for
-ffast-math (which defines __FAST_MATH__) and disable hardfloat
(plus emit a #warning) when it is set.

This patch just adds common code. Some operations will be migrated
to hardfloat in subsequent patches to ease bisection.

Note: some architectures (at least PPC, there might be others) clear
the status flags passed to softfloat before most FP operations. This
precludes the use of hardfloat, so to avoid introducing a performance
regression for those targets, we add a flag to disable hardfloat.
In the long run though it would be good to fix the targets so that
at least the inexact flag passed to softfloat is indeed sticky.

Backports commit a94b783952cc493cb241aabb1da8c7a830385baa from qemu
2018-12-19 10:32:32 -05:00
bindings bindings/README: Add D bindings 2018-10-06 04:51:47 -04:00
docs
include cpu: Convert cpu_index into a bitmap 2018-03-21 08:06:07 -04:00
msvc Makefile: Rename TARGET_DIRS to TARGET_LIST 2018-06-08 19:22:45 -04:00
qemu fpu: introduce hardfloat 2018-12-19 10:32:32 -05:00
samples Fuzz 2018-10-06 04:49:11 -04:00
tests Fuzz builds ok 2018-10-06 04:55:02 -04:00
.appveyor.yml
.gitignore qapi: Move qapi-schema.json to qapi/, rename generated files 2018-03-09 11:35:11 -05:00
.travis.yml
AUTHORS.TXT
Brewfile
ChangeLog
config.mk
COPYING
COPYING.LGPL2
COPYING_GLIB
CREDITS.TXT Adding Philippe Antoine to CREDITS 2018-10-06 04:50:10 -04:00
install-cmocka-linux.sh
list.c
make.sh
Makefile Fuzz 2018-10-06 04:49:11 -04:00
msvc.bat
pkgconfig.mk
README.md
uc.c i386: Fix initialization of x86 targets 2018-09-03 09:14:35 -04:00
windows_export.bat

Unicorn Engine

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Unicorn is a lightweight, multi-platform, multi-architecture CPU emulator framework based on QEMU.

Unicorn offers some unparalleled features:

  • Multi-architecture: ARM, ARM64 (ARMv8), M68K, MIPS, SPARC, and X86 (16, 32, 64-bit)
  • Clean/simple/lightweight/intuitive architecture-neutral API
  • Implemented in pure C language, with bindings for Crystal, Clojure, Visual Basic, Perl, Rust, Ruby, Python, Java, .NET, Go, Delphi/Free Pascal and Haskell.
  • Native support for Windows & *nix (with Mac OSX, Linux, *BSD & Solaris confirmed)
  • High performance via Just-In-Time compilation
  • Support for fine-grained instrumentation at various levels
  • Thread-safety by design
  • Distributed under free software license GPLv2

Further information is available at http://www.unicorn-engine.org

License

This project is released under the GPL license.

Compilation & Docs

See docs/COMPILE.md file for how to compile and install Unicorn.

More documentation is available in docs/README.md.

Contact

Contact us via mailing list, email or twitter for any questions.

Contribute

If you want to contribute, please pick up something from our Github issues.

We also maintain a list of more challenged problems in a TODO list.

CREDITS.TXT records important contributors of our project.