tree 62ff858a189b69f2f239fbd5eca722a525ebd0b7
parent 1849128c7d88247d914f05efe4c03907f0932174
author Eli Friedman <eli.friedman@gmail.com> 1211806779 +0000
committer Eli Friedman <eli.friedman@gmail.com> 1211806779 +0000

Emit memmove, not memcpy, for structure copies; this is unfortunately 
required for correctness in cases of copying a struct to itself or to 
an overlapping struct (itself for cases like *a = *a, and overlapping 
is possible with unions).

Hopefully, this won't end up being a perf issue; LLVM *should* be able 
to optimize memmove to memcpy in a lot of cases, and for small copies 
the generated code *should* be mostly comparable. (In reality, LLVM 
is currently horrible at optimizing memmove, but that's a bug, not a 
fundamental issue.)

gcc currently generates wrong code; that's 
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32667.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@51566 91177308-0d34-0410-b5e6-96231b3b80d8