Commit Graph

3 Commits

Author SHA1 Message Date
Chris Lattner d3210e1a20 instcombine transforms vector loads that are only used by
extractelement operations into a bitcast of the pointer,
then a gep, then a scalar load.  Disable this when the vector
only has one element, because it leads to infinite loops in
instcombine (PR4908).

This transformation seems like a really bad idea to me, as it
will likely disable CSE of vector load/stores etc and can be
better done in the code generator when profitable.  This
goes all the way back to the first days of packed types,
r25299 specifically.

I'll let those people who care about the performance of vector
code decide what to do with this.

llvm-svn: 81185
2009-09-08 03:44:51 +00:00
Chris Lattner 0cdbc7a2ca fix ComputeMaskedBits handling of zext/sext/trunc to work with vectors.
This fixes PR4905

llvm-svn: 81174
2009-09-08 00:13:52 +00:00
Chris Lattner 4e3e930743 fix a bug I introduced with my 'instcombine builder' refactoring
changes: SimplifyDemandedBits can't use the builder yet because it
has the wrong insertion point.  This fixes a crash building
MultiSource/Benchmarks/PAQ8p

llvm-svn: 80537
2009-08-31 04:36:22 +00:00