X86: Decode PALIGN operands so I don't have to do it in my head.
llvm-svn: 173572
diff --git a/llvm/lib/Target/X86/Utils/X86ShuffleDecode.cpp b/llvm/lib/Target/X86/Utils/X86ShuffleDecode.cpp
index 8b87c1f..9694808 100644
--- a/llvm/lib/Target/X86/Utils/X86ShuffleDecode.cpp
+++ b/llvm/lib/Target/X86/Utils/X86ShuffleDecode.cpp
@@ -61,6 +61,14 @@
ShuffleMask.push_back(NElts+i);
}
+void DecodePALIGNMask(MVT VT, unsigned Imm, SmallVectorImpl<int> &ShuffleMask) {
+ unsigned NumElts = VT.getVectorNumElements();
+ unsigned Offset = Imm * (VT.getVectorElementType().getSizeInBits() / 8);
+
+ for (unsigned i = 0; i != NumElts; ++i)
+ ShuffleMask.push_back((i + Offset) % (NumElts * 2));
+}
+
/// DecodePSHUFMask - This decodes the shuffle masks for pshufd, and vpermilp*.
/// VT indicates the type of the vector allowing it to handle different
/// datatypes and vector widths.