7bb65dd434
This patch corrects the FXSAVE and FXRSTOR Macroops. The actual code used for saving/restore the FP registers is in the file but it was not used. The FXSAVE and FXRSTOR instructions are used in the kernel for saving and loading the state of the mmx,xmm and fpu registers. This operation is triggered in FS by issuing a Device Not Available Fault. The cr0 register has a TS flag that is set upon each context change. Every time a task access any FP related register (SIMD as well) if the TS flag is set to one, the device not available fault is issued. The kernel saves the current state of the registers, and restore the previous state of the currently running task. Right now Gem5 lacks of this capability. the Device Not Available Fault is never issued, leading to several problems when different threads share the same CPU and SMT is not used. The PARSEC Ferret benchmark is an example of this behavior. In order to test this a hack in the atomic cpu code was done to detect if a static instruction has any FP operands and the cr0 reg TS bit is set. This check must be done in the ISA dependent code. But it seems to be tricky to access the cr0 register while executing an instruction. Committed by: Nilay Vaish <nilay@cs.wisc.edu>
This is the gem5 simulator. The main website can be found at http://www.gem5.org A good starting point is http://www.gem5.org/Introduction, and for more information about building the simulator and getting started please see http://www.gem5.org/Documentation and http://www.gem5.org/Tutorials. To build gem5, you will need the following software: g++ or clang, Python (gem5 links in the Python interpreter), SCons, SWIG, zlib, m4, and lastly protobuf if you want trace capture and playback support. Please see http://www.gem5.org/Dependencies for more details concerning the minimum versions of the aforementioned tools. Once you have all dependencies resolved, type 'scons build/<ARCH>/gem5.opt' where ARCH is one of ALPHA, ARM, NULL, MIPS, POWER, SPARC, or X86. This will build an optimized version of the gem5 binary (gem5.opt) for the the specified architecture. See http://www.gem5.org/Build_System for more details and options. With the simulator built, have a look at http://www.gem5.org/Running_gem5 for more information on how to use gem5. The basic source release includes these subdirectories: - configs: example simulation configuration scripts - ext: less-common external packages needed to build gem5 - src: source code of the gem5 simulator - system: source for some optional system software for simulated systems - tests: regression tests - util: useful utility programs and files To run full-system simulations, you will need compiled system firmware (console and PALcode for Alpha), kernel binaries and one or more disk images. Please see the gem5 download page for these items at http://www.gem5.org/Download If you have questions, please send mail to gem5-users@gem5.org Enjoy using gem5 and please share your modifications and extensions.