GCC Wont generate BFI

GCC wont generate BFI

test.cc:

#include <stdint.h>

uint32_t emplace(uint32_t into, uint32_t what) {
	constexpr uint32_t shift = 5;
	constexpr uint32_t width = 4;
	constexpr uint32_t mask = ((1 << width) - 1) << shift;
	return (into & ~mask) | ((what << shift) & mask);
}

(abridged) test.s generated by arm-none-eabi-g++ -Wall -Wextra -mcpu=cortex-m4 test.cc -c -S -O3:

.LFB0:
	@ args = 0, pretend = 0, frame = 0
	@ frame_needed = 0, uses_anonymous_args = 0
	@ link register save eliminated.
	lsls	r1, r1, #5
	and	r1, r1, #480
	bic	r0, r0, #480
	orrs	r0, r0, r1
	bx	lr
  
(abridged) test.s generated by clang -target arm-none-eabi -Wall -Wextra -mcpu=cortex-m4 test.cc -c -S -O3:

_Z7emplacejj:
	.fnstart
	bfi	r0, r1, #5, #4
	bx	lr