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Diffstat (limited to 'llvm/lib/Target/ARM/README.txt')
| -rw-r--r-- | llvm/lib/Target/ARM/README.txt | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/llvm/lib/Target/ARM/README.txt b/llvm/lib/Target/ARM/README.txt index 068c441ed73..0252a4aef41 100644 --- a/llvm/lib/Target/ARM/README.txt +++ b/llvm/lib/Target/ARM/README.txt @@ -552,3 +552,23 @@ __Z11no_overflowjj: //===---------------------------------------------------------------------===// +Some of the NEON intrinsics may be appropriate for more general use, either +as target-independent intrinsics or perhaps elsewhere in the ARM backend. +Some of them may also be lowered to target-independent SDNodes, and perhaps +some new SDNodes could be added. + +For example, maximum, minimum, and absolute value operations are well-defined +and standard operations, both for vector and scalar types. + +The current NEON-specific intrinsics for count leading zeros and count one +bits could perhaps be replaced by the target-independent ctlz and ctpop +intrinsics. It may also make sense to add a target-independent "ctls" +intrinsic for "count leading sign bits". Likewise, the backend could use +the target-independent SDNodes for these operations. + +ARMv6 has scalar saturating and halving adds and subtracts. The same +intrinsics could possibly be used for both NEON's vector implementations of +those operations and the ARMv6 scalar versions. + +//===---------------------------------------------------------------------===// + |
