3-208
INSTRUCTION SET REFERENCE
FLDLoad Real
Description
This instruction pushes the source operand onto the FPU register stack. If the source operand is
in single- or double-real format, it is automatically converted to the extended-real format before
being pushed on the stack.
The FLD instruction can also push the value in a selected FPU register [ST(i)] onto the stack.
Here, pushing register ST(0) duplicates the stack top.
Operation
IF SRC is ST(i)
THEN
temp
<
ST(i)
TOP
<
TOP
?
1;
IF SRC is memory-operand
THEN
ST(0)
<
ExtendedReal(SRC);
ELSE (* SRC is ST(i) *)
ST(0)
<
temp;
FPU Flags Affected
C1
Set to 1 if stack overflow occurred; otherwise, cleared to 0.
C0, C2, C3
Undefined.
Floating-Point Exceptions
#IS
Stack overflow occurred.
#IA
Source operand is an sNaN value or unsupported format.
#D
Source operand is a denormal value. Does not occur if the source operand
is in extended-real format.
Opcode
Instruction
Description
D9 /0
FLD m32real
Push m32real onto the FPU register stack.
DD /0
FLD m64real
Push m64real onto the FPU register stack.
DB /5
FLD m80real
Push m80real onto the FPU register stack.
D9 C0+i
FLD ST(i)
Push ST(i) onto the FPU register stack.
