tree 9e3f9060cb92547d474b3563e3d334cb9bbf111b
parent ccefbbd0f02c5036dd1244ee5c6603f365653fbe
author Thomas Lively <tlively@google.com> 1548815009 +0000
committer Thomas Lively <tlively@google.com> 1548815009 +0000

[WebAssembly] Optimize BUILD_VECTOR lowering for size

Summary:
Implements custom lowering logic that finds the optimal value for the
initial splat of the vector and either uses it or uses v128.const if
it is available and if it would produce smaller code. This logic
replaces large TableGen ISEL patterns that would lower all non-splat
BUILD_VECTORs into a splat followed by a fixed number of replace_lane
instructions. This CL fixes PR39685.

Reviewers: aheejin

Subscribers: dschuff, sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D56633

llvm-svn: 352592