GNU gcc commit:

af0907d... 	PR middle-end/56420 	* expmed.c (EXACT_POWER_OF_2_OR_ZERO_P): Do subtraction in uhwi, to 	avoid signed wrapping. 	(expand_mult): Handle properly multiplication by 	((dword_type) -1) << (BITS_PER_WORD - 1).  Improve multiplication by 	((dword_type) 1) << (BITS_PER_WORD - 1).  Avoid undefined behavior 	in the compiler if coeff is HOST_WIDE_INT_MIN. 	(expand_divmod): Don't make ext_op1 static, change it's type to 	uhwi.  Avoid undefined behavior in -INTVAL (op1).