Merging r195635:

Merging r195635:
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r195635 | dsanders | 2013-11-25 11:14:43 +0000 (Mon, 25 Nov 2013) | 19 lines

Fixed tryFoldToZero() for vector types that need expansion.

Summary:
Moved the requirement for SelectionDAG::getConstant() to return legally
typed nodes slightly earlier. There were two optional DAGCombine passes
that were missed out and were required to produce type-legal DAGs.

Simplified a code-path in tryFoldToZero() to use SelectionDAG::getConstant().
This provides support for both promoted and expanded vector types whereas the
previous code only supported promoted vector types.

Fixes a "Type for zero vector elements is not legal" assertion detected by
an llvm-stress generated test.

Reviewers: resistor

CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D2251
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_34@195651 91177308-0d34-0410-b5e6-96231b3b80d8