Displaying 1 result from an estimated 1 matches for "computeknownbitsfromoperator".
2016 Jul 30
3
Reasoning about results of min and max with a constant
Hi all,
Say we have this IR:
%1 = icmp slt i16 %x, 0
%.x = select i1 %1, i16 0, i16 %x
This is the canonical form of what is effectively max(x, 0).
From what I can tell LLVM has no facilities to determine from this code that %.x >= 0, so (for example) an SExt on %.x will not be converted to a ZExt.
I'm interested in seeing what sorts of changes would be needed to recognize this pattern