[PATCH] D8304: Fix backward operands in call to isTruncateFree() and improve comments.

[Steve King]

srking marked 4 inline comments as done.
srking added a comment.

In http://reviews.llvm.org/D8304#213632, @arsenm wrote:

> Do you have a testcase for this?


Unfortunately, I do not see a succinct way to test for this.  The bug is buried in a cost analysis algorithm.  The problem was detected by investigating nonsense truncation cases, i.e. where From < To.  By inspection, we see the original code places the destination as "From" and the operand as "To" in the truncation check.

I verified all "make check" tests pass with the patch.

Thanks,
-steve


http://reviews.llvm.org/D8304