--- arm.c (revision 190101) +++ arm.c (local) @@ -2982,6 +2982,31 @@ arm_gen_constant (enum rtx_code code, en return 1; } + /* On targets with UXTH/UBFX, we can deal with AND (2^N)-1 in a single + insn. */ + if (code == AND && (i = exact_log2 (remainder + 1)) > 0 + && (arm_arch_thumb2 || (i == 16 && arm_arch6 && mode == SImode))) + { + if (generate) + { + if (mode == SImode && i == 16) + /* Use UXTH in preference to UBFX, since on Thumb2 it's a + smaller insn. */ + emit_constant_insn (cond, + gen_zero_extendhisi2 + (target, gen_lowpart (HImode, source))); + else + /* Extz only supports SImode, but we can coerce the operands + into that mode. */ + emit_constant_insn (cond, + gen_extzv_t2 (gen_lowpart (mode, target), + gen_lowpart (mode, source), + GEN_INT (i), const0_rtx)); + } + + return 1; + } + /* Calculate a few attributes that may be useful for specific optimizations. */ /* Count number of leading zeros. */