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import os
from rpython.translator.tool.cbuild import ExternalCompilationInfo
from rpython.rtyper.tool import rffi_platform
from rpython.rlib.clibffi import FFI_DEFAULT_ABI, FFI_SYSV, FFI_VFP
from rpython.translator.platform import CompilationError
from rpython.rlib.debug import debug_print, debug_start, debug_stop
eci = ExternalCompilationInfo(
post_include_bits=["""
// we need to disable optimizations so the compiler does not remove this
// function when checking if the file compiles
static void __attribute__((optimize("O0"))) pypy__arm_has_vfp()
{
asm volatile("VMOV s0, s1");
}
"""])
def detect_hardfloat():
return FFI_DEFAULT_ABI == FFI_VFP
def detect_float():
"""Check for hardware float support
we try to compile a function containing a VFP instruction, and if the
compiler accepts it we assume we are fine
"""
try:
rffi_platform.verify_eci(eci)
return True
except CompilationError:
return False
def detect_arch_version(filename="/proc/cpuinfo"):
fd = os.open(filename, os.O_RDONLY, 0644)
n = 0
debug_start("jit-backend-arch")
try:
buf = os.read(fd, 2048)
if not buf:
n = 6 # we assume ARMv6 as base case
debug_print("Could not detect ARM architecture "
"version, assuming", "ARMv%d" % n)
finally:
os.close(fd)
# "Processor : ARMv%d-compatible processor rev 7 (v6l)"
i = buf.find('ARMv')
if i == -1:
n = 6
debug_print("Could not detect architecture version, "
"falling back to", "ARMv%d" % n)
else:
n = int(buf[i + 4])
if n < 6:
raise ValueError("Unsupported ARM architecture version")
debug_print("Detected", "ARMv%d" % n)
if n > 7:
n = 7
debug_print("Architecture version not explicitly supported, "
"falling back to", "ARMv%d" % n)
debug_stop("jit-backend-arch")
return n
# Once we can rely on the availability of glibc >= 2.16, replace this with:
# from rpython.rtyper.lltypesystem import lltype, rffi
# getauxval = rffi.llexternal("getauxval", [lltype.Unsigned], lltype.Unsigned)
def getauxval(type_, filename='/proc/self/auxv'):
fd = os.open(filename, os.O_RDONLY, 0644)
buf_size = 2048
struct_size = 8 # 2x uint32
try:
buf = os.read(fd, buf_size)
finally:
os.close(fd)
# decode chunks of 8 bytes (a_type, a_val), and
# return the a_val whose a_type corresponds to type_,
# or zero if not found.
i = 0
while i <= buf_size - struct_size:
# We only support little-endian ARM
a_type = (ord(buf[i]) |
(ord(buf[i+1]) << 8) |
(ord(buf[i+2]) << 16) |
(ord(buf[i+3]) << 24))
a_val = (ord(buf[i+4]) |
(ord(buf[i+5]) << 8) |
(ord(buf[i+6]) << 16) |
(ord(buf[i+7]) << 24))
i += struct_size
if a_type == type_:
return a_val
return 0
def detect_neon():
AT_HWCAP = 16
HWCAP_NEON = 1 << 12
hwcap = getauxval(AT_HWCAP)
return bool(hwcap & HWCAP_NEON)
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