PR rtl-optimization/37483
	* ifcvt.c (noce_try_sign_mask): Use if_info->test_bb instead of
	if_info->insn_b's bb as argument to optimize_bb_for_speed_p.
	Rearrange code to better match the original comment.  Check
	t_unconditional first.  Improve comment.

testsuite/
	* gcc.c-torture/compile/pr37483.c: New test.
	* gcc.c-torture/compile/pr37395.c: New test.

Co-Authored-By: Adam Nemet <anemet@caviumnetworks.com>

From-SVN: r140403