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
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 180b2c3..35a9bf7 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -3541,6 +3541,13 @@
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 @@
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) ||