This is a minor variant on the CR-based predicate-result mode. Where ored-result continues with independent element testing, data-dependent fail-first *stops* at the first failure:
+ if Rc=0: BO = inv<<2 | 0b00 # test CR.eq bit z/nz
for i in range(VL):
# predication test, skip all masked out elements.
if predicate_masked_out(i): continue # skip
VL = i # truncate: only successes allowed
break
# test passed: store result (and CR?)
- iregs[RT+i] = result
- if Rc=1: crregs[offs+i] = CRnew
+ if not RC1: iregs[RT+i] = result
+ if RC1 or Rc=1: crregs[offs+i] = CRnew
This is particularly useful, again, for FP operations that might overflow, where it is desirable to end the loop early, but also desirable to complete at least those operations that were okay (passed the test) without also having to sllow down execution by adding extra instructions that tested for the possibility of that failure, in advance of doing the actual calculation.