[Mlir-commits] [mlir] [MLIR] Prevent invalid IR from being passed outside of RemoveDeadValues (PR #121079)

[Renat Idrisov]

================
@@ -165,52 +213,62 @@ static SmallVector<OpOperand *> operandsToOpOperands(OperandRange operands) {
   return opOperands;
 }
 
-/// Clean a simple op `op`, given the liveness analysis information in `la`.
-/// Here, cleaning means:
-///   (1) Dropping all its uses, AND
-///   (2) Erasing it
-/// iff it has no memory effects and none of its results are live.
+/// Process a simple operation `op` using the liveness analysis `la`.
+/// If the operation has no memory effects and none of its results are live:
+///   1. Add the operation to a list for future removal, and
+///   2. Mark all its results as non-live values
 ///
-/// It is assumed that `op` is simple. Here, a simple op is one which isn't a
-/// function-like op, a call-like op, a region branch op, a branch op, a region
-/// branch terminator op, or return-like.
-static void cleanSimpleOp(Operation *op, RunLivenessAnalysis &la) {
-  if (!isMemoryEffectFree(op) || hasLive(op->getResults(), la))
+/// The operation `op` is assumed to be simple. A simple operation is one that
+/// is NOT:
+///   - Function-like
+///   - Call-like
+///   - A region branch operation
+///   - A branch operation
+///   - A region branch terminator
+///   - Return-like
+static void processSimpleOp(Operation *op, RunLivenessAnalysis &la,
+                            DenseSet<Value> &nonLiveSet,
+                            RDVFinalCleanupList &cl) {
+  if (!isMemoryEffectFree(op) || hasLive(op->getResults(), nonLiveSet, la))
     return;
 
-  op->dropAllUses();
-  op->erase();
+  cl.operations.push_back(op);
+  collectNonLiveValues(nonLiveSet, op->getResults(),
+                       BitVector(op->getNumResults(), true));
 }
 
-/// Clean a function-like op `funcOp`, given the liveness information in `la`
-/// and the IR in `module`. Here, cleaning means:
-///   (1) Dropping the uses of its unnecessary (non-live) arguments,
-///   (2) Erasing these arguments,
-///   (3) Erasing their corresponding operands from its callers,
-///   (4) Erasing its unnecessary terminator operands (return values that are
-///   non-live across all callers),
-///   (5) Dropping the uses of these return values from its callers, AND
-///   (6) Erasing these return values
+/// Process a function-like operation `funcOp` using the liveness analysis `la`
+/// and the IR in `module`. If it is not public or external:
----------------
parsifal-47 wrote:

oh, thank you, I did the other two because they sounded more concise

https://github.com/llvm/llvm-project/pull/121079