Fujitsu Fujitsu SPARC64 V manual Jump and Link, Exceptions fpdisabled

Models: Fujitsu SPARC64 V

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mem_address_not_aligned

Programming Note – The Multiply Add/Subtract instructions are encoded in the SPARC V9 IMPDEP2 opcode space, and they are specific to the SPARC64 V implementation. They cannot be used in any programs that will be executed on any other SPARC V9 processor, unless that implementation exactly matches the SPARC64 V use for the IMPDEP2 opcode.

Exceptions fp_disabled

fp_exception_ieee_754 (NV, NX, OF, UF)

illegal_instruction (size = 002 or 112) (fp_disabled is not checked for these encodings) fp_exception_other (unfinished_FPop)

A.29 Jump and Link

SPARC64 V clears the upper 32 bits of the PC value in r[rd] when PSTATE.AM is set (impl. dep. #125). The value written into r[rd] is visible to the instruction in the delay slot.

If either of the low-order two bits of the jump address is nonzero, a exception occurs. However, when the JMPL instruction

causes a mem_address_not_aligned trap, DSFSR and DSFAR are not updated.

If the JMPL instruction has r[rd] = 15, SPARC64 V stores PC + 8 in a hardware table called return address stack (RAS). When a ret (jmpl %i7+8, %g0) or retl (jmpl %o7+8, %g0) is executed, the value in the RAS is used to predict the return address.

JMPL with rd = 0 can be used to return from a subroutine. The typical return address is “r[31] + 8” if a nonleaf routine (one that uses the SAVE instruction) is entered by a CALL instruction, or “r[15] + 8” if a leaf routine (one that does not use the SAVE instruction) is entered by a CALL instruction or by a JMPL instruction with rd = 15.

Release 1.0, 1 July 2002

F. Chapter A Instruction Definitions: SPARC64 V Extensions 53

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Fujitsu Fujitsu SPARC64 V manual Jump and Link, Exceptions fpdisabled