Displaying 2 results from an estimated 2 matches for "vreg163".
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vreg16
2016 Dec 22
5
Understanding SlotIndexes
...slot and
see what VNInfo::def points to. Some scenarios I want to understand:
4B A = ...
10B D = use A
This seems straightforward. The instruction at slot 10 uses A at 10r
and the VNInfo for 10r should have a def at 4r.
But that's not right! I am staring at the following:
LiveInterval: %vreg163 [5404r,6432B:0)[6480B,6688r:0) 0 at 5404r
Instruction: 6688B %RDX<def> = COPY %vreg163
There is NO VNInfo at 6688r (the live range excludes it) but there is a
VNInfo at 6688e (Slot_EarlyClobber). How am I supposed to know which
slot to look at for a register use? Are ALL uses always at
S...
2016 Dec 25
0
Understanding SlotIndexes
...scenarios I want to understand:
>
> 4B A = ...
> 10B D = use A
>
> This seems straightforward. The instruction at slot 10 uses A at 10r
> and the VNInfo for 10r should have a def at 4r.
>
> But that's not right! I am staring at the following:
>
> LiveInterval: %vreg163 [5404r,6432B:0)[6480B,6688r:0) 0 at 5404r
> Instruction: 6688B %RDX<def> = COPY %vreg163
An instruction by itself doesn't have any meaningful slot. It shows as
B, but only because B is the default slot. For a given register you get
the actual slot from the live interval.
-Krzysz...