Philips Semiconductors
DSPCPU Operations for TM1100
File: ops.fm5, modified 7/23/99
PRELIMINARY INFORMATION
A-175
IEEE status ags from convert oating-point to
unsigned integer using PCSW rounding mode
SYNTAX
[ IF r
guard ] ufixieeeflags rsrc1
→ rdest
FUNCTION
if r
guard then
r
dest
← ieee_ags((unsigned long) ((oat)rsrc1))
ATTRIBUTES
Function unit
falu
Operation code
124
Number of operands
1
Modier
No
Modier range
—
Latency
3
Issue slots
1, 4
DESCRIPTION
The ufixieeeflags operation computes the IEEE exceptions that would result from converting the single-
precision IEEE oating-point value in r
src1 to an unsigned integer, and an integer bit vector representing the
computed exception ags is written into r
dest. The bit vector stored in rdest has the same format as the IEEE
exception bits in the PCSW. The exception ags 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, specied in r
guard. If a guard is present, its LSB
controls the modication of the destination register. If the LSB of r
guard is 1, rdest is written; otherwise, rdest is not
changed.
EXAMPLES
Initial Values
Operation
Result
r30 = 0x40400000 (3.0)
ufixieeeflags r30
→ r100
r100
← 0
r35 = 0x40247ae1 (2.57)
ufixieeeflags r35
→ r102
r102
← 0x02 (INX)
r10 = 0,
r40 = 0xff4fffff (–3.402823466e+38)
IF r10 ufixieeeflags r40
→ r105 no change, since guard is false
r20 = 1,
r40 = 0xff4fffff (–3.402823466e+38)
IF r20 ufixieeeflags r40
→ r110 r110 ← 0x10 (INV)
r45 = 0x7f800000 (+INF))
ufixieeeflags r45
→ r112
r112
← 0x10 (INV)
r50 = 0xbfc147ae (-1.51)
ufixieeeflags r50
→ r115
r115
← 0x10 (INV)
r60 = 0x00400000 (5.877471754e-39)
ufixieeeflags r60
→ r117
r117
← 0x20 (IFZ)
r70 = 0xffffffff (QNaN)
ufixieeeflags r70
→ r120
r120
← 0x10 (INV)
r80 = 0xffbfffff (SNaN)
ufixieeeflags r80
→ r122
r122
← 0x10 (INV)
OFZ
IFZ
INV
OVF
UNF
INX
DBZ
0
1
2
3
4
5
6
7
31
00
SEE ALSO
uxieeeags