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David P. Sanders dpsanders

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dpsanders / latency.txt
Created Jan 19, 2017 — forked from jboner/latency.txt
Latency Numbers Every Programmer Should Know
View latency.txt
Latency Comparison Numbers
L1 cache reference 0.5 ns
Branch mispredict 5 ns
L2 cache reference 7 ns 14x L1 cache
Mutex lock/unlock 25 ns
Main memory reference 100 ns 20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy 3,000 ns 3 us
Send 1K bytes over 1 Gbps network 10,000 ns 10 us
Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD
dpsanders /
Created Oct 15, 2015 — forked from gizmaa/
Various Julia plotting examples using PyPlot
View mxcsr.jl
function getmxcsr()
Base.llvmcall("""%ptr = alloca i32
call void @llvm.x86.sse.stmxcsr(i32 * %ptr)
%curval = load i32 * %ptr
ret i32 %curval""", UInt32, ())
function setmxcsr(u::UInt32)
Base.llvmcall("""%ptr = alloca i32
store i32 %0, i32 * %ptr