x86 Assembly Language Reference Manual

3.3 Floating-Point Instructions

The floating point instructions operate on floating-point, integer, and binary coded decimal (BCD) operands.

3.3.1 Data Transfer Instructions (Floating Point)

The data transfer instructions move floating-point, integer, and BCD values between memory and the floating point registers.

Table 14  Data Transfer Instructions (Floating-Point)

Oracle Solaris Mnemonic Intel/AMD Mnemonic Description Notes fbld FBLD load BCD fbstp FBSTP store BCD and pop fcmovb FCMOVB floating-point conditional move if below fcmovbe FCMOVBE floating-point conditional move if below or equal fcmove FCMOVE floating-point conditional move if equal fcmovnb FCMOVNB floating-point conditional move if not below fcmovnbe FCMOVNBE floating-point conditional move if not below or equal fcmovne FCMOVNE floating-point conditional move if not equal fcmovnu FCMOVNU floating-point conditional move if unordered fcmovu FCMOVU floating-point conditional move if unordered fild FILD load integer fist FIST store integer fistp FISTP store integer and pop fld FLD load floating-point value fst FST store floating-point value fstp FSTP store floating-point value and pop fxch FXCH exchange registers

3.3.2 Basic Arithmetic Instructions (Floating-Point)

The basic arithmetic instructions perform basic arithmetic operations on floating-point and integer operands.

Table 15  Basic Arithmetic Instructions (Floating-Point)

Oracle Solaris Mnemonic Intel/AMD Mnemonic Description Notes fabs FABS absolute value fadd FADD add floating-point faddp FADDP add floating-point and pop fchs FCHS change sign fdiv FDIV divide floating-point fdivp FDIVP divide floating-point and pop fdivr FDIVR divide floating-point reverse fdivrp FDIVRP divide floating-point reverse and pop fiadd FIADD add integer fidiv FIDIV divide integer fidivr FIDIVR divide integer reverse fimul FIMUL multiply integer fisub FISUB subtract integer fisubr FISUBR subtract integer reverse fmul FMUL multiply floating-point fmulp FMULP multiply floating-point and pop fprem FPREM partial remainder fprem1 FPREM1 IEEE partial remainder frndint FRNDINT round to integer fscale FSCALE scale by power of two fsqrt FSQRT square root fsub FSUB subtract floating-point fsubp FSUBP subtract floating-point and pop fsubr FSUBR subtract floating-point reverse fsubrp FSUBRP subtract floating-point reverse and pop fxtract FXTRACT extract exponent and significand

3.3.3 Comparison Instructions (Floating-Point)

The floating-point comparison instructions operate on floating-point or integer operands.

Table 16  Comparison Instructions (Floating-Point)

Oracle Solaris Mnemonic Intel/AMD Mnemonic Description Notes fcom FCOM compare floating-point fcomi FCOMI compare floating-point and set %eflags fcomip FCOMIP compare floating-point, set %eflags, and pop fcomp FCOMP compare floating-point and pop fcompp FCOMPP compare floating-point and pop twice ficom FICOM compare integer ficomp FICOMP compare integer and pop ftst FTST test floating-point (compare with 0.0) fucom FUCOM unordered compare floating-point fucomi FUCOMI unordered compare floating-point and set %eflags fucomip FUCOMIP unordered compare floating-point, set %eflags, and pop fucomp FUCOMP unordered compare floating-point and pop fucompp FUCOMPP compare floating-point and pop twice fxam FXAM examine floating-point

3.3.4 Transcendental Instructions (Floating-Point)

The transcendental instructions perform trigonometric and logarithmic operations on floating-point operands.

Table 17  Transcendental Instructions (Floating-Point)

Oracle Solaris Mnemonic Intel/AMD Mnemonic Description Notes f2xm1 F2XM1 computes 2x-1 fcos FCOS cosine fpatan FPATAN partial arctangent fptan FPTAN partial tangent fsin FSIN sine fsincos FSINCOS sine and cosine fyl2x FYL2X computes y * log2x fyl2xp1 FYL2XP1 computes y * log2(x+1)

3.3.5 Load Constants (Floating-Point) Instructions

The load constants instructions load common constants, such as π, into the floating-point registers.

Table 18  Load Constants Instructions (Floating-Point)

Oracle Solaris Mnemonic Intel/AMD Mnemonic Description Notes fld1 FLD1 load +1.0 fldl2e FLDL2E load log2e fldl2t FLDL2T load log210 fldlg2 FLDLG2 load log102 fldln2 FLDLN2 load loge2 fldpi FLDPI load π fldz FLDZ load +0.0

3.3.6 Control Instructions (Floating-Point)

The floating-point control instructions operate on the floating-point register stack and save and restore the floating-point state.

Table 19  Control Instructions (Floating-Point)

Oracle Solaris Mnemonic Intel/AMD Mnemonic Description Notes fclex FCLEX clear floating-point exception flags after checking for error conditions fdecstp FDECSTP decrement floating-point register stack pointer ffree FFREE free floating-point register fincstp FINCSTP increment floating-point register stack pointer finit FINIT initialize floating-point unit after checking error conditions fldcw FLDCW load floating-point unit control word fldenv FLDENV load floating-point unit environment fnclex FNCLEX clear floating-point exception flags without checking for error conditions fninit FNINIT initialize floating-point unit without checking error conditions fnop FNOP floating-point no operation fnsave FNSAVE save floating-point unit state without checking error conditions fnstcw FNSTCW store floating-point unit control word without checking error conditions fnstenv FNSTENV store floating-point unit environment without checking error conditions fnstsw FNSTSW store floating-point unit status word without checking error conditions frstor FRSTOR restore floating-point unit state fsave FSAVE save floating-point unit state after checking error conditions fstcw FSTCW store floating-point unit control word after checking error conditions fstenv FSTENV store floating-point unit environment after checking error conditions fstsw FSTSW store floating-point unit status word after checking error conditions fwait FWAIT wait for floating-point unit wait WAIT wait for floating-point unit