re PR target/40697 (inefficient code to extract least bits from an integer value)

re PR target/40697 (inefficient code to extract least bits from an integer value)

gcc/
	PR target/40697
	* optabs.c (avoid_expensive_constant): Use rtx_cost to find out
	the cost of loading the constant rather than assuming
	COSTS_N_INSNS (1).
	* config/arm/arm.c (thumb1_rtx_costs) <case CONST_INT>: If the
	outer code is AND, do the same tests as the andsi3 expander and
	return COSTS_N_INSNS (1) if and is cheap.

testsuite/
	PR target/40697
	* gcc.target/arm/thumb-andsi.c: New test.

From-SVN: r157582