Intel 80286, 80287 manual MOV Byte PTR IBP-121, OH Fldenv

NUMERIC PROGRAMMING EXAMPLES

CLEAR EXCEPTION FLAGS IN STATUS WORD

RESTORE MODIFIED STATE

IMAGE	BYTE PTR IBP-921, OH
MOV
FRSTOR	IBP-941
DE-ALLOCATE STACK SPACE, RtSTORE CPU REGISTERS
MOV	SP,BP
POP	BP
	/
RETURN TO	INTERRUPTED CALCULATION
IRET
SAVE_ALL	ENDP

Figure 4-3. Full-State Exception Handler (Cont'd.)

SAVE_ENVIRONMENT PROC

SAVE CPU REGISTERS, ALLOCATE STACK SPACE FOR 80287 ENVIRONMENT

PUSH BP

MOV BP,SP

SUB SP,14

SAVE ENVIRONMENT, WAIT FOR COMPLETION,

ENABLE CPU INTERRUPTS

FNSTENV IBP-141

FWAIT

S T I

APPLICATION EXCEPTION-HANDLING CODE GOES HERE

CLEAR EXCEPTION FLAGS IN STATUS WORD

RESTORE MODIFIED

ENVIRONMENT	IMAGE
MOV	BYTE PTR IBP-121, OH
FLDENV	IBP-141
DE-ALLOCATE STACK SPACE, RESTORE CPU REGISTERS
MOV	SP,BP
POP	BP

RETURN TO INTERRUPTED CALCULATION

IRE T

SAVE_ENVIRONMENT ENDP

Figure 4-4. Reduced-Latency Exception Handler

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