defm UXTB16 : AI_unary_rrot<0b01101100,
"uxtb16", UnOpFrag<(and node:$Src, 0x00FF00FF)>>;
-def : ARMV6Pat<(and (shl GPR:$Src, (i32 8)), 0xFF00FF),
- (UXTB16r_rot GPR:$Src, 24)>;
+// FIXME: This pattern incorrectly assumes the shl operator is a rotate.
+// The transformation should probably be done as a combiner action
+// instead so we can include a check for masking back in the upper
+// eight bits of the source into the lower eight bits of the result.
+//def : ARMV6Pat<(and (shl GPR:$Src, (i32 8)), 0xFF00FF),
+// (UXTB16r_rot GPR:$Src, 24)>;
def : ARMV6Pat<(and (srl GPR:$Src, (i32 8)), 0xFF00FF),
(UXTB16r_rot GPR:$Src, 8)>;