llvm-project.git/llvm/test/Transforms/JumpThreading/pr62908.ll, branch users/nico/python-2 Unnamed repository; edit this file 'description' to name the repository. [JumpThreading] Remove deleted BB from Unreachable (#126984) 2025-02-27T23:40:21+00:00 weiguozhi 57237827+weiguozhi@users.noreply.github.com 2025-02-27T23:40:21+00:00 11e65b98b3c0088a84ca5d1d74a0fd4bab462b40 Although an unreachable BB is skipped by processBlock, its successor can still be handled by processBlock, and maybeMergeBasicBlockIntoOnlyPred may merge the two BBs and delete the unreachable BB. Then the garbage pointer is left in Unreachable set. This patch avoids merging a BB into unreachable predecessor. 
Although an unreachable BB is skipped by processBlock, its successor can
still be handled by processBlock, and maybeMergeBasicBlockIntoOnlyPred
may merge the two BBs and delete the unreachable BB. Then the garbage
pointer is left in Unreachable set. This patch avoids merging a BB into 
unreachable predecessor.
 [ValueTracking] Check for known bits conflict for shl nsw (PR62908) 2023-05-24T08:54:10+00:00 Nikita Popov npopov@redhat.com 2023-05-24T08:52:18+00:00 92dc4fff87e46d262b7c40b31e2d3fb22211296d I removed the conflict check from computeKnownBitsFromShiftOperator() in D150648 assuming that this is now handled on the KnownBits side. However, the nsw handling is still inside ValueTracking, so we still need to handle conflicts there. Restore the check closer to where it is relevant. Fixes https://github.com/llvm/llvm-project/issues/62908. 
I removed the conflict check from computeKnownBitsFromShiftOperator()
in D150648 assuming that this is now handled on the KnownBits side.
However, the nsw handling is still inside ValueTracking, so we
still need to handle conflicts there. Restore the check closer to
where it is relevant.

Fixes https://github.com/llvm/llvm-project/issues/62908.