
Philips Semiconductors
DSPCPU Operations for TM1300
PRODUCT SPECIFICATION
A-175
IEEE status flags from convert floating-point to
unsigned integer using PCSW rounding mode
SYNTAX
[ IF rguard ] ufixieeeflags rsrc1
→
rdest
FUNCTION
if
rguard
then
rdest
←
ieee_flags((unsigned long) ((float)rsrc1))
ATTRIBUTES
Function unit
Operation code
Number of operands
Modifier
Modifier range
Latency
Issue slots
falu
124
1
No
—
3
1, 4
DESCRIPTION
The
ufixieeeflags
operation computes the IEEE exceptions that would result from converting the single-
precision IEEE floating-point value in rsrc1 to an unsigned integer, and an integer bit vector representing the
computed exception flags is written into rdest The bit vector stored in rdest has the same format as the IEEE
exception bits in the PCSW. The exception flags in PCSW are left unchanged by this operation. Rounding is according
to the IEEE rounding mode bits in PCSW. If an argument is denormalized, zero is substituted before computing the
conversion, and the IFZ bit in the result is set.
The
ufixieeeflags
operation optionally takes a guard, specified in rguard If a guard is present, its LSB controls
the modification of the destination register. If the LSB of rguardis 1, rdestis written; otherwise, rdestis not changed.
EXAMPLES
Initial Values
Operation
Result
r30 = 0x40400000 (3.0)
r35 = 0x40247ae1 (2.57)
r10 = 0,
r40 = 0xff4fffff (–3.402823466e+38)
r20 = 1,
r40 = 0xff4fffff (–3.402823466e+38)
r45 = 0x7f800000 (+INF))
r50 = 0xbfc147ae (-1.51)
r60 = 0x00400000 (5.877471754e-39)
r70 = 0xffffffff (QNaN)
r80 = 0xffbfffff (SNaN)
ufixieeeflags r30
→
r100
ufixieeeflags r35
→
r102
IF r10 ufixieeeflags r40
→
r105
r100
←
0
r102
←
0x02 (INX)
no change, since guard is false
IF r20 ufixieeeflags r40
→
r110
r110
←
0x10 (INV)
ufixieeeflags r45
→
r112
ufixieeeflags r50
→
r115
ufixieeeflags r60
→
r117
ufixieeeflags r70
→
r120
ufixieeeflags r80
→
r122
r112
←
0x10 (INV)
r115
←
0x10 (INV)
r117
←
0x20 (IFZ)
r120
←
0x10 (INV)
r122
←
0x10 (INV)
OFZ
IFZ
INV
OVF
UNF
INX
DBZ
0
1
2
3
4
5
6
7
0
31
0
SEE ALSO
ufixieee ifixieeeflags
ifixrzflags ufixrzflags
ufixieeeflags