combine.c (nonzero_bits, case PLUS): If pointers extend unsigned and this is the sum of a pointer and a constant...
* combine.c (nonzero_bits, case PLUS): If pointers extend unsigned
and this is the sum of a pointer and a constant, we know the result
did not overflow.
(num_sign_bit_copies, case PLUS): Likewise.
* explow.c (convert_memory_address): Remove opposite SUBREG.
* function.c (instantiate_new_reg): New function (from common code).
(instantiate_virtual_regs_1): Call it.
For PLUS, handle if (plus (subreg (virt-reg) (const_int))
if pointers sign- or zero-extend.
* simplify-rtx.c (simplify_unary_operation, case ZERO_EXTEND):
If pointers extend unsigned, use inside of SUBREG.
(simplify_unary_operation, case SIGN_EXTEND): Likewise, if sign extend.
From-SVN: r39489
