search for: dont_read_below

...the memory and is never used. I was told that llvm assumes that a function also can read below the pointer, so dead code elimination does not work here. The second thing i would like to have there is to tell LLVM that the interesting memory ends after the zero termination. I think these two flags: dont_read_below and dont_read_above_zero should be enough to make LLVM optimze that example. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20110912/a990e36f/attachment.html> -------------- next part -------------- A non-t...

...ever used. I was told that llvm assumes that a function also can read > below the pointer, so dead code elimination does not work here. The > second thing i would like to have there is to tell LLVM that the > interesting memory ends after the zero termination. I think these two > flags: dont_read_below and dont_read_above_zero should be enough to make > LLVM optimze that example. LLVM could figure out that there is no "below the pointer" by noticing that the object came from malloc. I think the missing optimization here is a heap->stack transform. I note that in your example t...