Intel Itanium 9150M, Manual, Page: 34 / 420

Volume 3: Instruction Reference 3:25
br
Operation:
if (ip_relative_form) // determine branch target
tmp_IP = IP + sign_ext(( imm
21
<< 4), 25);
else // indirect_form
tmp_IP = BR[ b
2
];
if ( btype != ‘ia’) // for Itanium branches,
tmp_IP = tmp_IP & ~0xf; // ignore bottom 4 bits of target
lower_priv_transition = 0;
switch ( btype ) {
case ‘cond’: // simple conditional branch
tmp_taken = PR[ qp ];
break;
case ‘call’: // call saves a return link
tmp_taken = PR[ qp ];
if (tmp_taken) {
BR[ b
1
] = IP + 16;
AR[PFS].pfm = CFM; // ... and saves the stack frame
AR[PFS].pec = AR[EC];
AR[PFS].ppl = PSR.cpl;
alat_frame_update(CFM.sol, 0);
rse_preserve_frame(CFM.sol);
CFM.sof -= CFM.sol;
// new frame size is size of outs
CFM.sol = 0;
CFM.sor = 0;
CFM.rrb.gr = 0;
CFM.rrb.fr = 0;
CFM.rrb.pr = 0;
}
break;
case ‘ret’: // return restores stack frame
Table 2-7. Branch Whether Hint
bwh Completer Branch Whether Hint
spnt Static Not-Taken
sptk Static Taken
dpnt Dynamic Not-Taken
dptk Dynamic Taken
Table 2-8. Sequential Prefetch Hint
ph Completer Sequential Prefetch Hint
few or none Few lines
many Many lines
Table 2-9. Branch Cache Deallocation Hint
dh Completer Branch Cache Deallocation Hint
none Don’t deallocate
clr Deallocate branch information