Sanjay Patel
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81ecbb0737
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Fix a logic bug in x86 vector codegen: sext (zext (x) ) != sext (x) (PR20472).
Remove a block of code from LowerSIGN_EXTEND_INREG() that was added with:
http://llvm.org/viewvc/llvm-project?view=revision&revision=177421
And caused:
http://llvm.org/bugs/show_bug.cgi?id=20472 (more analysis here)
http://llvm.org/bugs/show_bug.cgi?id=18054
The testcases confirm that we (1) don't remove a zext op that is necessary and (2) generate
a pmovz instead of punpck if SSE4.1 is available. Although pmovz is 1 byte longer, it allows
folding of the load, and so saves 3 bytes overall.
Differential Revision: http://reviews.llvm.org/D4909
llvm-svn: 216679
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2014-08-28 18:59:22 +00:00 |