[PATCH][AArch64] Improve bit-test-branch pattern to avoid unnecessary register clobber

[Richard Henderson]

On 12/15/2014 07:36 AM, Jiong Wang wrote:
> +	char buf[64];
> +	uint64_t val = ((uint64_t) 1) << UINTVAL (operands[1]);
> +	sprintf (buf, "tst\t%%<w>0, %"PRId64, val);
> +	output_asm_insn (buf, operands);
> +	return "<bcond>\t%l2";

Better to simply modify the operand, as in

  operands[1] = GEN_INT (HOST_WIDE_INT_1U << UINTVAL (operands[1]));
  return "tst\t%<w>0, %1\;<bcond>\t%l2";


r~