UM-32
This is a Rust implementation of the UM-32 "Universal Machine". You can find the specification, various VM images, and more information about the contest which originally spawned this horror at boundvariable.org.
Architecture
The Universal Machine consists of 8 unsigned 32 bit registers, a dynamically allocated heap containing arbitrarily sized arrays of unsigned 32 bit data, and 14 opcodes. Universal Machine images are stored as a sequence of unsigned 32 bit words with big-endian byte order.
Implementation
This is an extremely naive implementation written as an exercise to become better acquainted with Rust. It's currently a bit slower than Joe's C++ implementation. I'd like to correct this.
TODO
- build a decent test suite
- fix performance issues
tests
There is good coverage of the instruction parsing code, and no coverage of anything else. This will need to be fixed before trying to optimize.
performance
[jgrillo@localhost um32]$ sudo lshw -class cpu
*-cpu
description: CPU
product: Intel(R) Core(TM) i7-6820HQ CPU @ 2.70GHz
vendor: Intel Corp.
physical id: 6
bus info: cpu@0
version: Intel(R) Core(TM) i7-6820HQ CPU @ 2.70GHz
serial: None
slot: U3E1
size: 1392MHz
capacity: 4005MHz
width: 64 bits
clock: 100MHz
capabilities: x86-64 fpu fpu_exception wp vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp constant_tsc art arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf tsc_known_freq pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch cpuid_fault epb invpcid_single pti retpoline intel_pt tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 erms invpcid rtm mpx rdseed adx smap clflushopt xsaveopt xsavec xgetbv1 xsaves dtherm ida arat pln pts hwp hwp_notify hwp_act_window hwp_epp cpufreq
configuration: cores=4 enabledcores=4 threads=8
[jgrillo@localhost um32]$ time ./target/release/um32 ~/src/boundvariable/umbin/midmark.um
read 120440 bytes from /home/jgrillo/src/boundvariable/umbin/midmark.um
== UM beginning stress test / benchmark.. ==
4. 12345678.09abcdef
3. 6d58165c.2948d58d
2. 0f63b9ed.1d9c4076
1. 8dba0fc0.64af8685
0. 583e02ae.490775c0
Benchmark complete.
real 0m0.655s
user 0m0.651s
sys 0m0.002s
[jgrillo@localhost um32]$ time ./target/release/um32 ~/src/boundvariable/sandmark.umz
read 56364 bytes from /home/jgrillo/src/boundvariable/sandmark.umz
trying to Allocate array of size 0..
trying to Abandon size 0 allocation..
trying to Allocate size 11..
trying Array Index on allocated array..
trying Amendment of allocated array..
checking Amendment of allocated array..
trying Alloc(a,a) and amending it..
comparing multiple allocations..
pointer arithmetic..
check old allocation..
simple tests ok!
about to load program from some allocated array..
success.
verifying that the array and its copy are the same...
success.
testing aliasing..
success.
free after loadprog..
success.
loadprog ok.
== SANDmark 19106 beginning stress test / benchmark.. ==
100. 12345678.09abcdef
99. 6d58165c.2948d58d
98. 0f63b9ed.1d9c4076
...
3. 7c7394b2.476c1ee5
2. f3a52453.19cc755d
1. 2c80b43d.5646302f
0. a8d1619e.5540e6cf
SANDmark complete.
real 0m40.584s
user 0m40.451s
sys 0m0.020s
According to this source, the
midmark.um benchmark should run in "about one second".
These blog posts and articles provide a helpful introduction to profiling Rust programs:
