Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS MANUAL VOLUME 1 REV 2.3 Manual page 1473

FSQRT—Square Root
Opcode
D9 FA
Description
Calculates the square root of the source value in the ST(0) register and stores the
result in ST(0).
The following table shows the results obtained when taking the square root of various
classes of numbers, assuming that neither overflow nor underflow occurs.
SRC (ST(0))

 F
 0
 0
+F
+ 
NaN
Notes:
Fmeans finite-real number.
*indicates floating-point invalid-arithmetic-operand (#IA) exception.
Operation
ST(0)  SquareRoot(ST(0));
FPU Flags Affected
C1
C0, C2, C3
Floating-point Exceptions
#IS
#IA
#D
#P
Volume 4: Base IA-32 Instruction Reference
Instruction Description
FSQRT Calculates square root of ST(0) and stores the result in ST(0)
DEST (ST(0))
*
*
 0
 0
+F
+ 
NaN
Set to 0 if stack underflow occurred.
Indicates rounding direction if inexact-result exception (#P) is
generated: 0 = not roundup; 1 = roundup.
Undefined.
Stack underflow occurred.
Source operand is an SNaN value or unsupported format.
Source operand is a negative value (except for 0).
Source operand is a denormal value.
Value cannot be represented exactly in destination format.
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