o Replace __riscv64 with (__riscv && __riscv_xlen == 64)
This is required to support new GCC 7.1 compiler.
This is compatible with current GCC 6.1 compiler.
RISC-V is extensible ISA and the idea here is to have built-in define
per each extension, so together with __riscv we will have some subset
of these as well (depending on -march string passed to compiler):
__riscv_compressed
__riscv_atomic
__riscv_mul
__riscv_div
__riscv_muldiv
__riscv_fdiv
__riscv_fsqrt
__riscv_float_abi_soft
__riscv_float_abi_single
__riscv_float_abi_double
__riscv_cmodel_medlow
__riscv_cmodel_medany
__riscv_cmodel_pic
__riscv_xlen
Reviewed by: ngie
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D11901
This may be reworked upstream but in the interim should address the
stack usage issue reported in the PR.
PR: 206384
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
The key improvement is that it may be built without cross-unwinding
support, which significantly reduces the stack space requirement.
MFC after: 1 week
Relnotes: yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D7123
