x86 Instruction Set Reference
FFREE
Free Floating-Point Register
| Opcode | Mnemonic | Description |
|---|---|---|
DD C0+i |
FFREE |
ST(i) Sets tag for ST(i) to empty. |
| Description |
|---|
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Sets the tag in the FPU tag register associated with register ST(i) to empty (11B). The contents of ST(i) and the FPU stack-top pointer (TOP) are not affected. |
| Operation |
|---|
Tag(i) = 3; //11B |
| FPU flags affected |
|---|
|
C0, C1, C2, C3 undefined. |
| Floating-Point Exceptions |
|---|
| None. |
| Protected Mode Exceptions | ||
|---|---|---|
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| Real-Address Mode Exceptions | ||
|---|---|---|
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| Virtual-8086 Mode Exceptions | ||
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