[LLVMdev] Use of 'ldrd' instructions with unaligned addresses on armv7 (Major bug in LLVM optimizer?)
David Blaikie
dblaikie at gmail.com
Tue Jan 24 08:09:28 PST 2012
> Note that this code compiled with GCC 4.2 runs perfectly whereas LLVM will produce a binary that crashes: LLVM breaks existing source code.
On this point:
This is not uncommon - and the very nature of "Undefined Behaviour".
This reason alone is not enough to justify a change to Clang. We/you
would need to show that the behaviour is defined & Clang is violating
that definition.
Chris has posted about the general principle at length starting here:
http://blog.llvm.org/2011/05/what-every-c-programmer-should-know.html
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