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Unicorn CPU emulator framework (ARM, AArch64, M68K, Mips, Sparc, X86)
31013d5a8f
The SMLAD instruction is supposed to: * signed multiply Rn[15:0] * Rm[15:0] * signed multiply Rn[31:16] * Rm[31:16] * perform a signed addition of the products and Ra * set Rd to the low 32 bits of the theoretical infinite-precision result * set the Q flag if the sign-extension of Rd would differ from the infinite-precision result (ie on overflow) Our current implementation doesn't quite do this, though: it performs an addition of the products setting Q on overflow, and then it adds Ra, again possibly setting Q. This sometimes incorrectly sets Q when the architecturally mandated only-check-for-overflow-once algorithm does not. For instance: r1 = 0x80008000; r2 = 0x80008000; r3 = 0xffffffff smlad r0, r1, r2, r3 This is (-32768 * -32768) + (-32768 * -32768) - 1 The products are both 0x4000_0000, so when added together as 32-bit signed numbers they overflow (and QEMU sets Q), but because the addition of Ra == -1 brings the total back down to 0x7fff_ffff there is no overflow for the complete operation and setting Q is incorrect. Fix this edge case by resorting to 64-bit arithmetic for the case where we need to add three values together. Backports commit 5288145d716338ace0f83e3ff05c4d07715bb4f4 |
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| bindings | ||
| docs | ||
| include | ||
| msvc | ||
| qemu | ||
| samples | ||
| tests | ||
| .appveyor.yml | ||
| .gitignore | ||
| .travis.yml | ||
| AUTHORS.TXT | ||
| Brewfile | ||
| ChangeLog | ||
| config.mk | ||
| COPYING | ||
| COPYING_GLIB | ||
| COPYING.LGPL2 | ||
| CREDITS.TXT | ||
| install-cmocka-linux.sh | ||
| list.c | ||
| make.sh | ||
| Makefile | ||
| msvc.bat | ||
| pkgconfig.mk | ||
| README.md | ||
| uc.c | ||
| windows_export.bat | ||
Unicorn Engine
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.