The benchmarking summarized in
http://lists.llvm.org/pipermail/llvm-dev/2017-May/113525.html showed
this is beneficial for a wide range of cores.
As is to be expected, quite a few small adaptations are needed to the
regressions tests, as the difference in scheduling results in:
- Quite a few small instruction schedule differences.
- A few changes in register allocation decisions caused by different
instruction schedules.
- A few changes in IfConversion decisions, due to a difference in
instruction schedule and/or the estimated cost of a branch mispredict.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306514 91177308-0d34-0410-b5e6-96231b3b80d8
The 64/128-bit vector types are legal if NEON instructions are
available. However, there was no matching patterns for @llvm.cttz.*()
intrinsics and result in fatal error.
This commit fixes the problem by lowering cttz to:
a. ctpop((x & -x) - 1)
b. width - ctlz(x & -x) - 1
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242037 91177308-0d34-0410-b5e6-96231b3b80d8
Kristof Beyls