search for: computeknownbitsfromoperator

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