Displaying 5 results from an estimated 5 matches for "jb_1".
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bb_1
2018 Sep 11
2
linear-scan RA
...;
> If you wonder about the liveness information, you can perform experiments like this (I'm using a NOOP instruction with an implicit use operand to produce some artificial uses).
>
> $ cat test.mir
> name: somefunc
> body: |
> bb.0:
> %0:gr32 = MOV32ri 42
> JB_1 %bb.2, undef implicit $eflags
> JMP_1 %bb.2
>
> bb.1:
> %1:gr32 = MOV32ri 17
> JMP_1 %bb.3
>
> bb.2:
> NOOP implicit %0
> %1 = COPY %0
> JMP_1 %bb.3
>
> bb.3:
> NOOP implicit %1
>
>
>
> $ llc -run-pass=livein...
2018 Sep 11
2
linear-scan RA
...ormation, you can perform
> experiments like this (I'm using a NOOP instruction with an implicit use
> operand to produce some artificial uses).
> >
> > $ cat test.mir
> > name: somefunc
> > body: |
> > bb.0:
> > %0:gr32 = MOV32ri 42
> > JB_1 %bb.2, undef implicit $eflags
> > JMP_1 %bb.2
> >
> > bb.1:
> > %1:gr32 = MOV32ri 17
> > JMP_1 %bb.3
> >
> > bb.2:
> > NOOP implicit %0
> > %1 = COPY %0
> > JMP_1 %bb.3
> >
> > bb.3:
> >...
2018 Sep 11
2
linear-scan RA
The phi instruction is irrelevant; just the way I think about things.
The question is if the allocator believes that t0 and t2 interfere.
Perhaps the coalescing example was too simple.
In the general case, we can't coalesce without a notion of interference.
My worry is that looking at interference by ranges of instruction numbers
leads to inaccuracies when a range is introduced by a copy.
2018 Sep 11
2
linear-scan RA
...sing a NOOP instruction with an implicit use
> operand to produce some artificial uses).
> >> >
> >> > $ cat test.mir
> >> > name: somefunc
> >> > body: |
> >> > bb.0:
> >> > %0:gr32 = MOV32ri 42
> >> > JB_1 %bb.2, undef implicit $eflags
> >> > JMP_1 %bb.2
> >> >
> >> > bb.1:
> >> > %1:gr32 = MOV32ri 17
> >> > JMP_1 %bb.3
> >> >
> >> > bb.2:
> >> > NOOP implicit %0
> >> >...
2018 Sep 11
2
linear-scan RA
...licit use operand to produce some artificial uses).
>>>>>>
>>>>>> $ cat test.mir
>>>>>> name: somefunc
>>>>>> body: |
>>>>>> bb.0:
>>>>>> %0:gr32 = MOV32ri 42
>>>>>> JB_1 %bb.2, undef implicit $eflags
>>>>>> JMP_1 %bb.2
>>>>>>
>>>>>> bb.1:
>>>>>> %1:gr32 = MOV32ri 17
>>>>>> JMP_1 %bb.3
>>>>>>
>>>>>> bb.2:
>>>>>>...