Based on the OpLine spec, an OpLine instruction must be applied to
the instructions physically following it up to the first occurrence
of the next end of block, the next OpLine instruction, or the next
OpNoLine instruction.
```
OpLine %file 0 0
OpNoLine
OpLine %file 1 1
OpStore %foo %int_1
%value = OpLoad %int %foo
OpLine %file 2 2
```
For the above code, the current spirv-opt keeps three line
instructions `OpLine %file 0 0`, `OpNoLine`, and `OpLine %file 1 1`
in `std::vector<Instruction> dbg_line_insts_` of Instruction class
for `OpStore %foo %int_1`. It does not put any line instruction to
`std::vector<Instruction> dbg_line_insts_` of
`%value = OpLoad %int %foo` even though `OpLine %file 1 1` must be
applied to `%value = OpLoad %int %foo` based on the spec.
This results in the missing line information for
`%value = OpLoad %int %foo` while each spirv-opt pass optimizes the
code. We have to put `OpLine %file 1 1` to
`std::vector<Instruction> dbg_line_insts_` of
both `%value = OpLoad %int %foo` and `OpStore %foo %int_1`.
This commit conducts the line instruction propagation and skips
emitting the eliminated line instructions at the end, which are the same
with PropagateLineInfoPass and RedundantLineInfoElimPass. This
commit removes PropagateLineInfoPass and RedundantLineInfoElimPass.
KhronosGroup/glslang#2440 is a related PR that stop using
PropagateLineInfoPass and RedundantLineInfoElimPass from glslang.
When the code in this PR applied, the glslang tests will pass.
1. DebugValue/DebugDeclare references of load/store must not change
the behaviors of the convert-local-access-chains pass
2. We have to properly set the scope and line information of new
instructions made by the convert-local-access-chains pass
* Check var pointer capability in ADCE.
* Check var ptr capability for common uniform.
* Check var ptr capability in access chain convert.
Since we want this pass to run even if there are variable pointer on
storage buffers, we had to remove asserts that assumed there were no
variable pointers. The functions with the asserts will now work, it
becomes the responsibility of the callers to deal with the output as
appropriate.
* Single block elimination and variable pointers.
It seems like the code in local single block elimination is able to
handle cases with variable pointers already. This is because the
function `HasOnlySupportedRefs` ensures that variables that feed a
variable pointer are not candidates.
* Single store elimination and variable pointers.
It seems like the code in local single stroe elimination is able to
handle cases with variable pointers already. This is because the
function `FindSingleStoreAndCheckUses` ensures that variables that feed
a variable pointer are not candidates.
* SSA rewriter and variable pointers.
It seems like the code in the two passes that call the SSA rewriter are
able to handle cases with variable pointers already. This is because the
function `HasOnlySupportedRefs` ensures that variables that feed
a variable pointer are not candidates.
Fixes#2458.
* Copy decorations when creating new ids.
When creating a new value based on an old value, we need to copy the
decorations to the new id. This change does this in 3 places:
1) The variable holding the return value of the function generated by
merge return should get decorations from the function.
2) The results of the OpPhi instructions should get decorations from the
variable they are replacing in the ssa writer.
3) In local access chain convert the intermediate struct (result of
OpCompositeInsert) generated for the store replacement should get its
decorations from the variable being stored to.
Fixes#1787.
In local-access-chain-convert, we replace loads by load the entire
variable, then doing the extract. The extract will have the same value
as the load. However, if the load has a decoration on it, the
decoration is lost because we do not copy any them to the new id.
This is fixed by rewritting the load into the extract and keeping the
same result id.
This change has the effect that we do not call DCEInst on the loads
because the load is not being deleted, but replaced. This could leave
OpAccessChain instructions around that are not used. This is not a
problem for -O and -Os. They run local_single_*_elim passes and then
dead code elimination. The dce will remove the unused access chains,
and the load elimination passes work even if there are unused access
chains. I have added test to them to ensure they will not loss
opportunities.
Fixes#1787.
Re-formatted the source tree with the command:
$ /usr/bin/clang-format -style=file -i \
$(find include source tools test utils -name '*.cpp' -or -name '*.h')
This required a fix to source/val/decoration.h. It was not including
spirv.h, which broke builds when the #include headers were re-ordered by
clang-format.
