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f37c9c873c
When disassembling and BRW IR is available (which happens in the
generator), there will be pointers to the BRW's basic block structures
that are used to print the block numbers and predecessor/successors
in the output.
There are two challenges:
- Because DO and FLOW instructions are not real instructions, they are
not emitted in the output but would still cause the output to contain
empty blocks. Previous code accounted for DO but still had problems.
- DO blocks have special physical links that don't make sense when the
DO is not emitted at the end, but they would be shown even if that
block was omitted.
These issues can be seen here (edited to remove non-essential bits)
```
START B0 (2 cycles)
mov(8) g126<1>UD 0x3f800000UD
END B0 ->B1
START B2 <-B1 <-B4 (0 cycles)
END B2 ->B3
START B3 <-B2 (260 cycles)
LABEL1:
mov(8) g1<1>D 0D
cmp.ge.f0.0(8) null<1>D g2<0,1,0>D 10D
sync nop(1) null<0,1,0>UB
send(1) g0UD g1UD nullUD
(+f0.0) break(8) JIP: LABEL0 UIP: LABEL0
END B3 ->B1 ->B5 ->B4
START B4 <-B3 (1000 cycles)
sync nop(1) null<0,1,0>UB
mov(8) g126<1>UD g0<0,1,0>UD
LABEL0:
while(8) JIP: LABEL1
END B4 ->B2
START B5 <-B1 <-B3 (20 cycles)
```
For example:
- Block 1 is missing (a skipped DO block)
- Block 2 is empty (it was a FLOW block)
- Block 3 ends with a link to Block 1 (the special links involving DO
blocks).
Two key changes were made to fix this. First, skip the DO and FLOW
blocks completely. The use_tail ensures that the instruction group is
reused to avoid empty blocks. Second, when printing, the successors and
predecessors, walk through the skipped blocks. And finally, don't print
the special blocks.
With the fix, here's the output. Note the blocks retain their original
BRW IR number.
```
START B0 (2 cycles)
mov(8) g127<1>UD 0x3f800000UD
END B0 ->B3
START B3 <-B0 <-B4 (260 cycles)
LABEL1:
mov(8) g1<1>D 0D
cmp.ge.f0.0(8) null<1>D g2<0,1,0>D 10D
sync nop(1) null<0,1,0>UB
send(1) g0UD g1UD nullUD
(+f0.0) break(8) JIP: LABEL0 UIP: LABEL0
END B3 ->B5 ->B4
START B4 <-B3 (1000 cycles)
sync nop(1) null<0,1,0>UB
mov(8) g127<1>UD g0<0,1,0>UD
LABEL0:
while(8) JIP: LABEL1
END B4 ->B3
START B5 <-B3 (20 cycles)
```
Issue was spotted by Ken.
Fixes:
|
||
|---|---|---|
| .. | ||
| blorp | ||
| ci | ||
| common | ||
| compiler | ||
| decoder | ||
| dev | ||
| ds | ||
| executor | ||
| genxml | ||
| isl | ||
| nullhw-layer | ||
| perf | ||
| shaders | ||
| tools | ||
| vulkan | ||
| vulkan_hasvk | ||
| meson.build | ||