tree e7af453594dabc078f5cf80e911912c74a7f20c5
parent c5e28d6d933ee6b1c2635101ed64a1b8ef8df6fc
author Tobias Grosser <tobias@grosser.es> 1440586874 +0000
committer Tobias Grosser <tobias@grosser.es> 1440586874 +0000

Only use instructions as insert locations for SCEVExpander

SCEVExpander, which we are using during code generation, only allows
instructions as insert locations, but breaks in case BasicBlock->end() iterators
are passed to it due to it trying to obtain the basic block in which code should
be generated by calling Instruction->getParent(), which is not defined for
->end() iterators.

This change adds an assert to Polly that ensures we only pass valid instructions
to SCEVExpander and it fixes one case, where we used IRBuilder->SetInsertBlock()
to set an ->end() insert location which was later passed to SCEVExpander.

In general, Polly is always trying to build up the CFG first, before we actually
insert instructions into the CFG sceleton. As a result, each basic block should
already have at least one branch instruction before we start adding code. Hence,
always requiring the IRBuilder insert location to be set to a real instruction
should always be possible.

Thanks Utpal Bora <cs14mtech11017@iith.ac.in> for his help with test case
reduction.

This is a backport from r243830 as it was committed on trunk.

git-svn-id: https://llvm.org/svn/llvm-project/polly/branches/release_37@246029 91177308-0d34-0410-b5e6-96231b3b80d8