C STANDARD UNDEFINED BEHAVIOR VERSUS WITTGENSTEIN 1. DEPRESSING AND FAINTLY TERRIFYING Chris Lattner, the architect of the Clang/LLVM C compiler explained the effects of the
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More UB madness from LLVM/Clang
Via @johnregehr this further tale of compiler “optimizations” that break correct C code without even a warning by deleting a necessary null pointer check. In
Read moreinformal methods applied to networks and timeouts
Distributed computation involves many interesting issues concerning shared data. Here I want to sketch out what networks look like using applied (informal) mathematics so we
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Types considered harmful. From a remark by Wolfram.
Originally Nov 30, 2017. (revised 2021,2023) Russell introduced what is often viewed as his most original contribution to mathematical logic: his theory of types—which in
Read moreC compiler developers are hostile to C programming
From the LLVM developer mailing list this remarkable exchange in which Chris Lattner of LLVM says that the compiler use of undefined behavior (UB) is
Read moreThe C standard versus C and the mother of all hacks.
The Kafkaesque interaction of the C standard and the main open source C compilers was concisely outlined by one of the main LLVM authors back
Read moreThe C standard committee effort to kill C continues
Consider the following code: void f(void) { unsigned char x[1]; /* intentionally uninitialized */ x[0] ^= x[0]; printf(“%d\n”, x[0]); printf(“%d\n”, x[0]); return; } In this
Read moreChang-Maxemchuk atomic broadcast
The Chang-Maxemchuk algorithm (US Patent 4,725,834 ) solves atomic broadcast (and in-order broadcast) problems for distributed networks in a far simpler and more efficient way than some
Read moreData base design criteria: ease of use
Regarding ease-of-use, it’s often struck me when reviewing data systems papers that the evaluation sections are full of performance and correctness criteria, but only rarely
Read moreDistributed consensus and network reliability
All of the distributed consensus algorithms I have been reviewing recently (Paxos, Raft, Zab, Chang Maxemchuck, Viewstamped, … ) are based on a number of
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