Why should I know this?

define 8 x i16> @src(4 x i16> %x, 4 x i16> %y, 4 x i16> %z) { %cmp.xy = icmp slt 4 x i16> %x, %y %cmp.yz = icmp slt 4 x i16> %y, %z  %select.xz = select 4 x i1> %cmp.xy, 4 x i16> %x, 4 x i16> %z %select.yx = select 4 x i1> %cmp.yz, 4 x i16> %y, 4 x i16> %x %res = shufflevector 4 x i16> %select.xz, 4 x i16> %select.yx, 8 x i32> i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7> ret 8 x i16> ..