Commit 13f67dd5 authored by Alexander Graf's avatar Alexander Graf
Browse files

s390x: Add some documentation in opcode list 



I find it really hard to grasp what each field in the opcode list means.
Slowly walking through its semantics myself, I figured I'd write a small
summary at the top of the file to make life easier for me and whoever
looks at the file next.

Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
Reviewed-by: default avatarRichard Henderson <rth@twiddle.net>
parent c095ed73

target-s390x/insn-data.def

+21 −0
Original line number Diff line number Diff line 
/*

 *  Arguments to the opcode prototypes

 *

 *  C(OPC,    NAME,    FMT,   FAC, I1, I2, P, W, OP, CC)

 *  D(OPC,    NAME,    FMT,   FAC, I1, I2, P, W, OP, CC, DATA)

 *

 *  OPC  = (op << 8) | op2 where op is the major, op2 the minor opcode

 *  NAME = name of the opcode, used internally

 *  FMT  = format of the opcode (defined in insn-format.def)

 *  FAC  = facility the opcode is available in (defined in DisasFacility)

 *  I1   = func in1_xx fills o->in1

 *  I2   = func in2_xx fills o->in2

 *  P    = func prep_xx initializes o->*out*

 *  W    = func wout_xx writes o->*out* somewhere

 *  OP   = func op_xx does the bulk of the operation

 *  CC   = func cout_xx defines how cc should get set

 *  DATA = immediate argument to op_xx function

 *

 *  The helpers get called in order: I1, I2, P, OP, W, CC

 */



/* ADD */

    C(0x1a00, AR,      RR_a,  Z,   r1, r2, new, r1_32, add, adds32)

    C(0xb9f8, ARK,     RRF_a, DO,  r2, r3, new, r1_32, add, adds32)