Standard Library
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Package ieee (in ieee.i) -
Index of documented functions or symbols:
DOCUMENT as_chars(x)
as_chars, x, xnew
return the bits of X as an array of char
return value has leading dimension of sizeof(x(1)), otherwise
same dimensions as X
in second form, sets bits of X to char array XNEW
DOCUMENT ieee.i
native_align, native_fix, native_flt, native_flim, native_dlim
describe the binary formats of the native primitive numeric types
as_chars(x) -- gets/sets bits of x as char array
ieee_test(x) -- tests for ieee754 special values
ieee_set(x,what) -- sets ieee754 special values
DOCUMENT ieee_set, x, what
set X to ieee754 special value WHAT
X must be an array of float or double values
(note that X cannot be a scalar double value)
WHAT = 0 means leave unchanged
WHAT = 1 means set to Inf
WHAT = 2 means set to qNaN
WHAT = 3 means set to sNaN
WHAT = 4 means set to 0.0
negate WHAT to set the sign bit of X as well
WHAT may be an array conformable with X, in order to set only
some values of X
this routine is a no-op if this machine is not known to
support these ieee754 special values
Warning-- apparently there is no universal standard for what
constitutes signalling versus quiet NaN
on MIPS and HPPA architectures, qNaN and sNaN are reversed
DOCUMENT ieee_test(x) return values: 0 if this is an ordinary number -1 if this is -Inf 1 if this is Inf 2 if this is qNaN 3 if this is sNaN 4 if this is a denormal 5 if this is a denormal which will be treated as NaN Warning-- apparently there is no universal standard for what constitutes signalling versus quiet NaN on MIPS and HPPA architectures, qNaN and sNaN are reversed
DOCUMENT native_align =
[char_align, short_align, int_align, long_align,
float_align, double_align, pointer_align, struct_align]
struct_align may be -1 for ppc/ibm interpretation
-2 for ppc/gcc interpretation
SEE: native_flim
DOCUMENT native_fix = [short_format, int_format, long_format]
format = [sizeof(type), order]
order = 1 for big-endian (most significant byte first)
-1 for little-endian (least significant byte first)
DOCUMENT native_flim = [big, tiny, eps] big is the biggest number tiny is the smallest non-denormal number eps is smallest number such that 1+eps != 1
DOCUMENT native_flt = [float_format, double_format]
format = [sizeof(type), order, sgn_addr, exp_addr, exp_size,
man_addr, man_size, man_norm, exp_bias, denorm]
order = 1 for big-endian (most significant byte first)
-1 for little-endian (least significant byte first)
(interpreted code here does not yet handle VAX middle-endian)
addr, size are bit address (from msb), number of bits
man_norm is 0 if mantissa 1-bit implied, 1 if 1-bit explicit
exp_bias is the exponent field for 1.0
denorm is 0 if there are no denormals
1 if there are functioning denormals
2 if denormals exist but are treated as NaNs