FPU INSTRUCTIONS 10222021 TUCN dr Emil CEBUC Outline

FPU INSTRUCTIONS 10/22/2021 TUC-N dr. Emil CEBUC

Outline l l l General FPU Instruction format FPU Instruction families Examples 10/22/2021 TUC-N dr. Emil CEBUC

FPU Instructions l l l l Data movement Data conversions Constant Instructions Arithmetic Instructions Comparison Instructions Transcendental Instructions Miscellaneous Instructions 10/22/2021 TUC-N dr. Emil CEBUC

General FPU Instruction format [label: ] Fopcode op 1, op 2 [label: ] Fopcode. P ST(1), ST(0) op 1 Stack Register ST(0… 7), or memory op 2 Stack Register ST(0… 7) 10/22/2021 TUC-N dr. Emil CEBUC

Data movement FLD memory Loads memory short, long or temp real number to TOS, TOP (Top Of stack Pointer is decremented) FLD ST(i) FLD ST(0) duplicates TOS 10/22/2021 TUC-N dr. Emil CEBUC

Data movement cont. FST memory Stores TOS to memory in short or long real format FSTP memory Stores TOS to memory in short, long or temporary real format TOP is incremented and TOS set to empty 10/22/2021 TUC-N dr. Emil CEBUC

Data conversion FILD memory Loads word, doubleword or quadword integer from memory and converts to temporary real to TOS, decrements TOP FIST memory Stores TOS memory and converts to word or doubleword 10/22/2021 TUC-N dr. Emil CEBUC

Data conversion cont FISTP memory Stores TOS to memory and converts to word, doubleword or quadword increments TOP, frees TOS IF value in TOS is non integer rounding is performed according to bits in CTRL word 10/22/2021 TUC-N dr. Emil CEBUC

Data conversion cont. FBLD memory Loads and converts Packed BCD operand from memory to TOS FBSTP memory Stores to memory and converts to Packed BCD, pops TOS 10/22/2021 TUC-N dr. Emil CEBUC

Constant instructions FLD 1 Push +1. 0 to TOS FLDL 2 T Push log 210 to TOS FLDL 2 E Push log 2 e to TOS FLDPI Push π to TOS FLDLG 2 Push log 102 to TOS FLDLN 2 Push loge 2 to TOS FLDZ Push +0. 0 to TOS 10/22/2021 TUC-N dr. Emil CEBUC

Arithmetic instructions FIADD memory adds memory word, doubleword or quadword integer to TOS FADD memory adds memory short, long or temporary real to TOS FADD st(i) adds st(i) to TOS FADDP add TOS to st(1) and pop TOS FADDP st(i), st(0) add TOS to ST(i) and pop TOS 10/22/2021 TUC-N dr. Emil CEBUC

Arithmetic instructions cont. FISUB memory subtracts memory word, doubleword or quadword integer from TOS FSUB memory subtracts memory short, long or temporary real from TOS FSUB st(0), st(1) subtracts st(i) from TOS FSUBP subtracts TOS from st(1) and pop TOS FSUBP st(i), st(0) subtracts TOS from ST(i) and pop TOS 10/22/2021 TUC-N dr. Emil CEBUC

Arithmetic instructions cont. FSUBR reverse subtract FISUBR memory subtracts TOS from memory word, doubleword or quadword integer FSUBR memory TOS from subtracts memory short, long or temporary real FSUBR st(0), st(1) subtracts TOS from st(i) FSUBRP subtracts st(1) from TOS and pop TOS FSUBRP st(i), st(0) subtracts TOS from ST(i) and pop TOS 10/22/2021 TUC-N dr. Emil CEBUC

Arithmetic instructions cont. FMUL MULTIPLY FMUL memory real FIMUL memory int FMUL ST(0), ST(i) Multiply ST(0) by ST(i) and store in ST(0) FMUL ST(i), ST(0) Multiply ST(i) by ST(0) and store in ST(i) FMULP ST(i), ST(0) Multiply ST(i) by ST(0), store result in ST(i), and pop the register stack. FMULP Multiply ST(1) by ST(0), store result in ST(1), and pop the register stack 10/22/2021 TUC-N dr. Emil CEBUC

Arithmetic instructions cont. FDIV division FDIV memory real FIDIV memory integer divide TOS by memory, result in TOS FDIV ST(0), ST(i) Divide ST(0) by ST(i) and store result in ST(0) FDIV ST(i), ST(0) Divide ST(i) by ST(0) and store result in ST(i) FDIVP ST(i), ST(0) Divide ST(i) by ST(0), store result in ST(i), and pop the register stack. FDIVP Divide ST(1) by ST(0), store result in ST(1), and pop the register stack 10/22/2021 TUC-N dr. Emil CEBUC

Arithmetic instructions cont. FDIVR memory real Divide by ST(0) store in TOS FDIVR ST(0), ST(i) Divide ST(i) by ST(0) store TOS FDIVR ST(i), ST(0) Divide ST(0) by ST(i). FDIVRP ST(i), ST(0) Divide ST(0) by ST(i), store ST(i), pop the register stack. FDIVRP Divide ST(0) by ST(1), store in ST(1), pop the register stack. FIDIVR memory int Divide by ST(0) store in TOS 10/22/2021 TUC-N dr. Emil CEBUC

Arithmetic instructions cont. FRNDINT FABS FCHS 10/22/2021 TUC-N dr. Emil CEBUC

Comparison Instructions FCOM ST(i) Compare ST(0) with ST(i) FCOM Compare ST(0) with ST(1) FCOMP ST(i) Compare ST(0) with ST(i) and pop register stack FCOMP Compare ST(0) with ST(1) and pop register stack FCOMPP Compare ST(0) with ST(1) and pop register stack twice FTEST COMPARE WITH 0. 0 Results in C 3, C 2, C 0 bits of FPU status word 10/22/2021 TUC-N dr. Emil CEBUC

Transcendental Instructions FSQRT FPTAN FPATAN FSIN FCOS fyl 2 x and fyl 2 xp 1 instructions compute st(1) * log 2(st(0)) and st(1) * log 2(st(0)+1), st(0)>0 f 2 xm 1 2**ST(0)-1 -1<ST(0)<1 10/22/2021 TUC-N dr. Emil CEBUC

Miscellaneous Instructions FINIT FWAIT FFREE ST(i) FLDCW FSTCW FLDENV FSTENV 10/22/2021 TUC-N dr. Emil CEBUC