This fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/3873.
In the presence of variable pointers, the reaching definition may be
another pointer. For example, the following fragment:
%2 = OpVariable %_ptr_Input_float Input
%11 = OpVariable %_ptr_Function__ptr_Input_float Function
OpStore %11 %2
%12 = OpLoad %_ptr_Input_float %11
%13 = OpLoad %float %12
corresponds to the pseudo-code:
layout(location = 0) in flat float *%2
float %13;
float *%12;
float **%11;
*%11 = %2;
%12 = *%11;
%13 = *%12;
which ultimately, should correspond to:
%13 = *%2;
During rewriting, the pointer %12 is found to be replaceable by %2.
However, when processing the load %13 = *%12, the type of %12's reaching
definition is another float pointer (%2), instead of a float value.
When this happens, we need to continue looking up the reaching definition
chain until we get to a float value or a non-target var (i.e. a variable
that cannot be SSA replaced, like %2 in this case since it is a function
argument).
This commit add support for optimizer to not inline functions with DontInline control flag, so that the [noinline] attribute in HLSL will be useful in DXC SPIR-V generation.
This is part of work of github.com/microsoft/DirectXShaderCompiler/issues/3158
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.
For some cases, we have DebugDecl invisible to a value assignment, but
the value assignment information is important i.e., debugger cannot inspect
the variable without the information. For example, a parameter of an inlined
function must have its value assignment i.e., argument passing out of its
function scope. If we simply remove DebugDecl because it is invisible to the
argument passing, we cannot inspec the variable.
This PR
- Adds DebugValue for DebugDecl invisible to a value assignment. We use
the value of the variable in the basic block that contains DebugDecl, which is
found by ssa-rewrite. If the value instruction does not dominate DebugDecl,
we use the value of the variable in the immediate dominator of the basic block.
- Checks the visibility of DebugDecl for Phi value assignment based on the
all value operands of the Phi. Since Phi just references multiple values from
multiple basic blocks, scopes of value operands must be regarded as the scope
of the Phi.
`DebugInfoManager::AddDebugValueIfVarDeclIsVisible()` adds
OpenCL.DebugInfo.100 DebugValue from DebugDeclare only when the
DebugDeclare is visible to the give scope. It helps us correctly
handle a reference variable e.g.,
{ // scope #1.
int foo = /* init */;
{ // scope #2.
int& bar = foo;
...
in the above code, we must not propagate DebugValue of `int& bar` for
store instructions in the scope #1 because it is alive only in
the scope #2.
We have an exception: If the given DebugDeclare is used for a function
parameter, `DebugInfoManager::AddDebugValueIfVarDeclIsVisible()` has
to always add DebugValue instruction regardless
of the scope. It is because the initializer (store instruction) for
the function parameter can be out of the function parameter's scope
(the function) in particular when the function was inlined.
Without this change, the function parameter value information always
disappears whenever we run the function inlining pass and
`DebugInfoManager::AddDebugValueIfVarDeclIsVisible()`.
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
In #3636, I missed that the instruction folder may create more than a
single constant per call. Since CCP was only checking whether one
constant had been created after folding, it was wrongly thinking that
the IR had not changed.
Fixes#3738.
This PR adds the NestingDepth function to StructuredCFGAnalysis.
This function, given a block id, returns the number of merge
constructs containing it.
This is needed by spirv-fuzz, but it makes sense to add it to
StructuredCFGAnalaysis, which contains related functionalities.
When we update OpenCL.DebugInfo.100 lexical scopes e.g., DebugFunction,
we have to replace DebugScope of each instruction that uses the lexical
scope correctly.
It is possible that the result of a void function call is used. In case
it is used, we need something that still defines its id after inlining.
We use an undef for that purpose.
Fixes https://github.com/KhronosGroup/SPIRV-Tools/issues/3704
CCP should mark IR changed if it created new constants.
This fixes#3636.
When CCP is simulating statements, it will sometimes successfully fold
an instruction, which laters switches to varying. The initial fold of
the instruction may generate a new constant K.
The problem we were running into is when K never gets propagated to the
IR. Its definition will still exist, so CCP should mark the IR modified
in this case.
In fixing this bug, I noticed that an existing test was suffering from
the same bug. The change also makes PassTest::SinglePassRunAndMatch()
return the result from the pass, so that we can check that the pass
marks the IR modified in this case.
In the existing code, ADCE pass does not check DebugScope of an
instruction when it checks the users of each instruction, which results
in removing OpenCL.Debug.100 instructions that are only used by
DebugScope. This commit lets ADCE pass add DebugScope of an instruction
to the live instruction set when the instruction is added to the live
instruction set.
* No longer blindly add global non-semantic info instructions to global
types and values
* functions now have a list of non-semantic instructions that succeed
them in the global scope
* global non-semantic instructions go in global types and values if
they appear before any function, otherwise they are attached to the
immediate function predecessor in the module
* changed ADCE to use the function removal utility
* Modified EliminateFunction to have special handling for non-semantic
instructions in the global scope
* non-semantic instructions are moved to an earlier function (or full
global set) if the function they are attached to is eliminated
* Added IRContext::KillNonSemanticInfo to remove the tree of
non-semantic instructions that use an instruction
* this is used in function elimination
* There is still significant work in the optimizer to handle
non-semantic instructions fully in the optimizer
For each local variable, ssa-rewrite should remove its DebugDeclare
if and only if it is replaced by any number of DebugValues for store
and phi instructions.
For example, when we have two variables `a` whose DebugDeclare
will be replaced to DebugValues by ssa-rewrite pass and `b` whose
DebugDeclare will not be replaced, we have to remove only DebugDeclare
for `a`, not `b`.
When we copy the loop body to unroll it, we have to copy its
instructions but DebugDeclare or DebugValue used for the declaration
i.e., DebugValue with Deref must not be copied and only the first block
can contain those instructions.
1. Set the debug scope and line information for the new replacement
instructions.
2. Replace DebugDeclare and DebugValue if their OpVariable or value
operands are replaced by scalars. It uses 'Indexes' operand of
DebugValue. For example,
struct S { int a; int b;}
S foo; // before scalar replacement
int foo_a; // after scalar replacement
int foo_b;
DebugDeclare %dbg_foo %foo %null_expr // before
DebugValue %dbg_foo %foo_a %Deref_expr 0 // after
DebugValue %dbg_foo %foo_b %Deref_expr 1 // means Value(foo.members[1]) == Deref(%foo_b)
Essentially, it marks all DebugInfo instructions in functions (and their operands) as live. It treats DebugDeclare and DebugValue with Deref as loads and so marks Stores of their variables as live.
It marks each DebugGlobalVariables as live except for its variable. After closure, it rechecks if the variable is live. If not, the DebugGlobalVariable instruction's variable operand is set to DebugInfoNone, per the DebugInfo spec.
This pass basically follows the same process as ssa-rewrite: it adds a DebugValue after each Store and removes the DebugDeclare or DebugValue Deref. It only does this if all instructions that are dependent on the Store are Loads and are replaced.
This commit lets the vector DCE pass preserve the OpenCL.DebugInfo.100
information properly. When the vector DCE pass determines the liveness
of instructions, the debug instructions must not affect the decision. In
addition, when it kills some instructions, it has to kill DebugValue
instructions that use the killed instructions. When it updates some
composite values to meaningful values (not undef), it has to remove
DebugValue because the value information becomes incorrect.
The decision to reduce the load must be not affected by debug
instructions. For example, even when a DebugValue references a
result id of a loaded composite value, this change lets the
reduce-load-size pass reduce the load if the full composite value is not
used anywhere other than the DebugValue.
When the pass replaces the local variable `OpVariable` ids to their
corresponding pointers, we have to update operands of DebugValue or
DebugDeclare instructions.
When there are multiple entries and the shader has a variable with
WorkGroup storage class, those multiple entry functions store values to
the variable. Since ADCE pass uses def-use chains to propagate the work
list, some of instructions in the work list are not actually a part of
the currently processed function. As a result, it adds instructions in
other functions and put them in |live_insts_|. However, it does not
have the control flow information for those instructions in other
functions i.e., |block2headerBranch_| and |header2nextHeaderBranch_|.
When it processes those instructions (they are added when it processes a
different function), it skips handling them because they are already in
|live_insts_| and does not check |block2headerBranch_| and
|header2nextHeaderBranch_|, which results in skipping some branches.
Even though those branches are live branches, it considers they are dead
branches.
For many spirv-opt passes such as simplify-instructions pass, we have to
correctly clear the OpenCL.DebugInfo.100 debug information for
KillInst() and ReplaceAllUses(). If we keep some debug information that
disappeared because of KillInst() and ReplaceAllUses(), adding new
DebugValue instructions based on the existing DebugDeclare information
will generate incorrect information. This CL update DebugInfoManager
and IRContext to correctly clear debug information.
* Support load and extract pattern in desc_sroa.
* Fix typo in comments.
* Load replacement var before use; and added test.
* fix formatting
* Address code review comments.
Add OpenCL.DebugInfo.100 `DebugValue` instructions for store
and phi instructions of local variables to provide the debugger with
the updated values of local variables correctly.
