Re: [PATCH 3/3][AArch64] Improve zero extend

2016-07-20 Thread Richard Earnshaw (lists)
On 19/07/16 16:32, Wilco Dijkstra wrote: > On AArch64 the UXTB and UXTH instructions are aliases of UBFM, > which does a shift as part of its operation. An AND immediate is a > simpler operation, and might be faster on some implementations, so it is > better to emit this this instead of UBFM. > >

[PATCH 3/3][AArch64] Improve zero extend

2016-07-19 Thread Wilco Dijkstra
On AArch64 the UXTB and UXTH instructions are aliases of UBFM, which does a shift as part of its operation. An AND immediate is a simpler operation, and might be faster on some implementations, so it is better to emit this this instead of UBFM. Benchmarking showed no difference on implementations