Pull in r248439 from upstream llvm trunk (by Sanjay Patel):
set div/rem default values to 'expensive' in TargetTransformInfo's cost model ...because that's what the cost model was intended to do. As discussed in D12882, this fix has a temporary unintended consequence for SimplifyCFG: it causes us to not speculate an fdiv. However, two wrongs make PR24818 right, and two wrongs make PR24343 act right even though it's really still wrong. I intend to correct SimplifyCFG and add to CodeGenPrepare to account for this cost model change and preserve the righteousness for the bug report cases. https://llvm.org/bugs/show_bug.cgi?id=24818 https://llvm.org/bugs/show_bug.cgi?id=24343 Differential Revision: http://reviews.llvm.org/D12882
This fixes the too-eager fdiv hoisting in pow(), which could lead to
unexpected floating point exceptions.