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Intel 253666-024US User Manual

Page 338

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3-292 Vol. 2A

FADD/FADDP/FIADD—Add

INSTRUCTION SET REFERENCE, A-M

FPU Flags Affected

C1

Set to 0 if stack underflow occurred.
Set if result was rounded up; cleared otherwise.

C0, C2, C3

Undefined.

Floating-Point Exceptions

#IS

Stack underflow occurred.

#IA

Operand is an SNaN value or unsupported format.
Operands are infinities of unlike sign.

#D

Source operand is a denormal value.

#U

Result is too small for destination format.

#O

Result is too large for destination format.

#P

Value cannot be represented exactly in destination format.

Protected Mode Exceptions

#GP(0)

If a memory operand effective address is outside the CS, DS,

ES, FS, or GS segment limit.

If the DS, ES, FS, or GS register contains a NULL segment

selector.

#SS(0)

If a memory operand effective address is outside the SS

segment limit.

#NM

CR0.EM[bit 2] or CR0.TS[bit 3] = 1.

#PF(fault-code)

If a page fault occurs.

#AC(0)

If alignment checking is enabled and an unaligned memory

reference is made while the current privilege level is 3.

#UD

If the LOCK prefix is used.

Real-Address Mode Exceptions

#GP

If a memory operand effective address is outside the CS, DS,

ES, FS, or GS segment limit.

#SS

If a memory operand effective address is outside the SS

segment limit.

#NM

CR0.EM[bit 2] or CR0.TS[bit 3] = 1.

#UD

If the LOCK prefix is used.

Virtual-8086 Mode Exceptions

#GP(0)

If a memory operand effective address is outside the CS, DS,

ES, FS, or GS segment limit.

#SS(0)

If a memory operand effective address is outside the SS

segment limit.