Commit Graph

2 Commits

Author SHA1 Message Date
James Molloy e9d50dc9f7 Compute demanded bits for icmp instructions
Instead of bailing out when we see an icmp, we can instead at least
say that if the upper bits of both operands are known zero, they are
not demanded. This doesn't help with signed comparisons, but it's at
least better than bailing out.

llvm-svn: 249687
2015-10-08 12:40:06 +00:00
James Molloy bcd7f0ac98 Treat Mul just like Add and Subtract
Like adds and subtracts, muls ripple only to the left so we can use
the same logic.

While we're here, add a print method to DemandedBits so it can be used
with -analyze, which we'll use in the testcase.

llvm-svn: 249686
2015-10-08 12:39:59 +00:00