The VTBL (and VTBX) instructions are rather permissive concerning the masks they

accept. If a value in the mask is out of range, it uses the value 0, for VTBL,
or leaves the value unchanged, for VTBX.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127700 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bill Wendling 2011-03-15 21:15:20 +00:00
parent 13ba2527f7
commit 0d4c9d94f6

View File

@ -3541,6 +3541,13 @@ static bool isVREVMask(const SmallVectorImpl<int> &M, EVT VT,
return true;
}
static bool isVTBLMask(const SmallVectorImpl<int> &M, EVT VT) {
// We can handle <8 x i8> vector shuffles. If the index in the mask is out of
// range, then 0 is placed into the resulting vector. So pretty much any mask
// of 8 elements can work here.
return VT == MVT::v8i8 && M.size() == 8;
}
static bool isVTRNMask(const SmallVectorImpl<int> &M, EVT VT,
unsigned &WhichResult) {
unsigned EltSz = VT.getVectorElementType().getSizeInBits();
@ -3980,6 +3987,7 @@ ARMTargetLowering::isShuffleMaskLegal(const SmallVectorImpl<int> &M,
isVREVMask(M, VT, 32) ||
isVREVMask(M, VT, 16) ||
isVEXTMask(M, VT, ReverseVEXT, Imm) ||
isVTBLMask(M, VT) ||
isVTRNMask(M, VT, WhichResult) ||
isVUZPMask(M, VT, WhichResult) ||
isVZIPMask(M, VT, WhichResult) ||