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cleaned up comments

This commit is contained in:
em2machine 2025-12-22 13:10:42 +01:00
parent c39c3f09a6
commit 89fbb7c5b4
2 changed files with 20 additions and 13 deletions
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7
src/V3UndrivenCapture.cpp
View File

@ -156,8 +156,7 @@ const std::vector<V3UndrivenCapture::Var>& V3UndrivenCapture::computeWriteSummar
UINFO(DBG, "undriven capture recursion detected at "
<< taskNameQ(taskp)
<< " returning directWrites size=" << info.directWrites.size());
// Cycle detected. Simple behaviour:
// return directWrites only to guarantee termination.
// Cycle detected. return directWrites only to guarantee termination.
if (info.writeSummary.empty()) info.writeSummary = info.directWrites;
sortUniqueVars(info.writeSummary);
return info.writeSummary;
@ -168,18 +167,20 @@ const std::vector<V3UndrivenCapture::Var>& V3UndrivenCapture::computeWriteSummar
// Start with direct writes
info.writeSummary = info.directWrites;
// Union in callees
// Need callees
for (FTask calleep : info.callees) {
if (m_info.find(calleep) == m_info.end()) continue;
const std::vector<Var>& sub = computeWriteSummary(calleep);
info.writeSummary.insert(info.writeSummary.end(), sub.begin(), sub.end());
}
// Remove duplicates and sort because grabbing all of the callees can result in duplicates
sortUniqueVars(info.writeSummary);
UINFO(DBG, "undriven capture writeSummary computed size=" << info.writeSummary.size()
<< " for " << taskNameQ(taskp));
// We are done, so set the m_info state correctly and return the vector of variables
info.state = State::DONE;
return info.writeSummary;
}

26
src/V3UndrivenCapture.h
View File

@ -32,6 +32,9 @@ public:
using Var = AstVar*;
// DFS computation state for writeSummary propagation.
// UNVISITED: write summary not computed yet
// VISITING: currently computing on the call stack - used to detect cycles
// DONE: write summary computed
enum class State : uint8_t { UNVISITED, VISITING, DONE };
struct FTaskInfo final {
@ -39,24 +42,25 @@ public:
std::vector<Var> directWrites;
// Direct resolved callees from this task/function body.
std::vector<FTask> callees;
// 'write through write' writeSummary for the given task/function.
// 'write through write' writeSummary for the given task/function. Meaning ultimately everything that this function/task writes to.
std::vector<Var> writeSummary;
// state for writeSummary computation.
State state = State::UNVISITED;
};
// Enable writeSummary computation. If disabled, then the existing V3Undriven behaviour is used.
static bool enableWriteSummary;
private:
// Per-task/function capture info keyed by resolved AstNodeFTask* identity.
// Per-task/function capture info keyed by resolved AstNodeFTask* identity (FTask = function or task). This is our 'graph' of tasks/functions. Each node has a list of direct callees and a list of variables written in the function body. There are methods to remove duplicates otherwise this could explode.
std::unordered_map<FTask, FTaskInfo> m_info;
// Sort and remove duplicates from a vector of variables.
// Sort and remove duplicates from a vector of variables. This is called after a task/function write summary is computed. writeSummary can accumulate duplicates if a variable is written in multiple tasks/functions.
static void sortUniqueVars(std::vector<Var>& vec);
// Sort and remove duplicates from a vector of callees.
// Sort and remove duplicates from a vector of callees. The visitor can record the same callee multiple times (multiple call sites, branches, etc).
static void sortUniqueFTasks(std::vector<FTask>& vec);
// Collect direct writes and call edges for all tasks/functions.
// Collect direct writes and call edges for all tasks/functions. Run one time when UndrivenCapture is created. This runs the visitor over the tree.
void gather(AstNetlist* netlistp);
// Compute (and cache) 'write through write' writeSummary for the given task/function.
const std::vector<Var>& computeWriteSummary(FTask taskp);
@ -65,18 +69,20 @@ public:
// Build capture database and precompute writeSummary for all discovered tasks/functions.
explicit V3UndrivenCapture(AstNetlist* netlistp);
// Lookup task/function capture info (nullptr if unknown).
// Lookup task/function capture info (nullptr if unknown). This is currently only used for the debug helper.
const FTaskInfo* find(FTask taskp) const;
// Get write through write through write, etc (call chain) writeSummary for a task/function
// (creates empty entry if needed).
// Get write through write through write, etc (call chain) writeSummary for a task/function (creates empty entry if needed). This returns a vector of variables that a particular task/function writes to, including all variables written by functions called by this task/function, and so on.
const std::vector<Var>& writeSummary(FTask taskp);
// used by the capture visitor
// used by the capture visitor to record information about tasks/functions and their statements and callees.
// noteTask() makes sure there is an entry for the given taskp.
void noteTask(FTask taskp);
// inside the body of taskp there is a write to variable varp
void noteDirectWrite(FTask taskp, Var varp);
// inside the body of callerp there is a call to calleep, this is needed so we can create a summary that includes all variables written by functions called by this task/function, and so on.
void noteCallEdge(FTask callerp, FTask calleep);
// Optional: dump one task's summary (for debug bring-up).
// dump one task's summary for debugging. leaving this in, in case need to debug future functionality.
void debugDumpTask(FTask taskp, int level = 9) const;
};