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.
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.
