Intel 64 and IA-32 Architectures Software Developers Manual Volume 1, Basic Architecture

Vol. 1 8-35

PROGRAMMING WITH THE X87 FPU

various classes of floating-point exceptions. This information pertains

to x87 FPU as well as SSE/SSE2/SSE3 extensions.

The following sections give specific information about how the x87 FPU handles

floating-point exceptions that are unique to the x87 FPU.

8.4.1 Arithmetic vs. Non-arithmetic Instructions

When dealing with floating-point exceptions, it is useful to distinguish between

arithmetic instructions and non-arithmetic instructions. Non-arithmetic

instructions have no operands or do not make substantial changes to their operands.

Arithmetic instructions do make significant changes to their operands; in particular,

they make changes that could result in floating-point exceptions being signaled.

Table 8-9 lists the non-arithmetic and arithmetic instructions. It should be noted that

some non-arithmetic instructions can signal a floating-point stack (fault) exception,

but this exception is not the result of an operation on an operand.

Table 8-9. Arithmetic and Non-arithmetic Instructions

Non-arithmetic Instructions Arithmetic Instructions

FABS F2XM1

FCHS FADD/FADDP

FCLEX FBLD

FDECSTP FBSTP

FFREE FCOM/FCOMP/FCOMPP

FINCSTP FCOS

FINIT/FNINIT FDIV/FDIVP/FDIVR/FDIVRP

FLD (register-to-register) FIADD

FLD (extended format from memory) FICOM/FICOMP

FLD constant FIDIV/FIDIVR

FLDCW FILD

FLDENV FIMUL

FNOP FIST/FISTP

FRSTOR FISUB/FISUBR

FSAVE/FNSAVE FLD (single and double)

FST/FSTP (register-to-register) FMUL/FMULP

FSTP (extended format to memory) FPATAN

FSTCW/FNSTCW FPREM/FPREM1

FSTENV/FNSTENV FPTAN