Simon Pilgrim d02c55204b [VectorLegalizer] Expansion of CTLZ using CTPOP when possible ...

This patch avoids scalarization of CTLZ by instead expanding to use CTPOP (ref: "Hacker's Delight") when the necessary operations are available.

This also adds the necessary cost models for X86 SSE2 targets (the main beneficiary) to ensure vectorization only happens when its useful.

Differential Revision: https://reviews.llvm.org/D25910

llvm-svn: 286233

2016-11-08 14:10:28 +00:00

7.2 KiB

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