FSTP
Usage: FSTP dest Modifies flags: See below
Copies the value in the ST(0) register to the 'dest' operand, which can be a memory location or another register in the FPU register stack. When storing the value in memory, the value is converted to single-precision or double-precision floating-point format.
Floating-Point Store
FST mem32 ; D9 /2 [8086,FPU]
FST mem64 ; DD /2 [8086,FPU]
FST fpureg ; DD D0+r [8086,FPU]
FSTP mem32 ; D9 /3 [8086,FPU]
FSTP mem64 ; DD /3 [8086,FPU]
FSTP mem80 ; DB /7 [8086,FPU]
FSTP fpureg ; DD D8+r [8086,FPU]
FST stores the value in ST0 into the given memory location or other FPU register. FSTP does the same, but then pops the register stack.
FPU Flags Affected C1 Set to 0 if stack underflow occurred. Indicates rounding direction of if the floating-point inexact exception (#P) is generated: 0 = not roundup;
1 =roundup. C0, C2, C3 Undefined.
EXAMPLE:
fstp Label