`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()`.
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.
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)
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.
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.
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.
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.
Handles the OpenCL100Debug extension in inlining. It preserves the information that is available while also adding the debug inlined at for all of the inlining that it does.
We need an analysis for OpenCL.DebugInfo.100 extension instructions such
as a map between function id and its DebugFunction. This commit add an
analysis for it.
