llvm-project/llvm/test/Transforms/SROA
Chandler Carruth 1bf38c6a71 Fix a really nasty SROA bug with how we handled out-of-bounds memcpy
intrinsics.

Reported on the list by Evan with a couple of attempts to fix, but it
took a while to dig down to the root cause. There are two overlapping
bugs here, both centering around the circumstance of discovering
a memcpy operand which is known to be completely outside the bounds of
the alloca.

First, we need to kill the *other* side of the memcpy if it was added to
this alloca. Otherwise we'll factor it into our slicing and try to
rewrite it even though we know for a fact that it is dead. This is made
more tricky because we can visit the sides in either order. So we have
to both kill the other side and skip instructions marked as dead. The
latter really should be goodness in every case, but here is a matter of
correctness.

Second, we need to actually remove the *uses* of the alloca by the
memcpy when queuing it for later deletion. Otherwise it may still be
using the alloca when we go to promote it (if the rewrite re-uses the
existing alloca instruction). Do this by factoring out the
use-clobbering used when for nixing a Phi argument and re-using it
across the operands of a to-be-deleted instruction.

llvm-svn: 199590
2014-01-19 12:16:54 +00:00
..
alignment.ll Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change. 2013-07-14 01:42:54 +00:00
basictest.ll Fix a really nasty SROA bug with how we handled out-of-bounds memcpy 2014-01-19 12:16:54 +00:00
big-endian.ll Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change. 2013-07-14 01:42:54 +00:00
fca.ll Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change. 2013-07-14 01:42:54 +00:00
phi-and-select.ll Fix a problem I introduced in r187029 where we would over-eagerly 2013-07-24 12:12:17 +00:00
vector-conversion.ll SROA: Handle casts involving vectors of pointers and integer scalars. 2013-09-21 20:36:04 +00:00
vector-promotion.ll Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change. 2013-07-14 01:42:54 +00:00
vectors-of-pointers.ll Rename the test so that we can add additional vectors-of-pointers tests 2012-12-18 05:50:54 +00:00