Merge pull request #70439 from meg-gupta/debugmsgs

[NFC] Add some debug logging to optimizer passes

Author: meg-gupta

lib/SILOptimizer/LoopTransforms/LoopUnroll.cpp

@@ -488,8 +488,12 @@ class LoopUnrolling : public SILFunctionTransform {
     auto *Fun = getFunction();
     SILLoopInfo *LoopInfo = PM->getAnalysis<SILLoopAnalysis>()->get(Fun);
 
+    LLVM_DEBUG(llvm::dbgs() << "Loop Unroll running on function : "
+                            << Fun->getName() << "\n");
+
     // Collect innermost loops.
     SmallVector<SILLoop *, 16> InnermostLoops;
+
     for (auto *Loop : *LoopInfo) {
       SmallVector<SILLoop *, 8> Worklist;
       Worklist.push_back(Loop);
@@ -503,11 +507,10 @@ class LoopUnrolling : public SILFunctionTransform {
       }
     }
 
-    if (InnermostLoops.empty())
+    if (InnermostLoops.empty()) {
+      LLVM_DEBUG(llvm::dbgs() << "No innermost loops\n");
       return;
-
-    LLVM_DEBUG(llvm::dbgs() << "Loop Unroll running on function : "
-                            << Fun->getName() << "\n");
+    }
 
     // Try to unroll innermost loops.
     for (auto *Loop : InnermostLoops)

lib/SILOptimizer/SILCombiner/SILCombine.cpp

@@ -420,6 +420,12 @@ bool SILCombiner::doOneIteration(SILFunction &F, unsigned Iteration) {
       MadeChange = true;
       continue;
     }
+#ifndef NDEBUG
+    std::string OrigIStr;
+#endif
+    LLVM_DEBUG(llvm::raw_string_ostream SS(OrigIStr); I->print(SS);
+               OrigIStr = SS.str(););
+    LLVM_DEBUG(llvm::dbgs() << "SC: Visiting: " << OrigIStr << '\n');
 
     // Canonicalize the instruction.
     if (scCanonicalize.tryCanonicalize(I)) {
@@ -456,13 +462,6 @@ bool SILCombiner::doOneIteration(SILFunction &F, unsigned Iteration) {
     // Then begin... SILCombine.
     Builder.setInsertionPoint(I);
 
-#ifndef NDEBUG
-    std::string OrigIStr;
-#endif
-    LLVM_DEBUG(llvm::raw_string_ostream SS(OrigIStr); I->print(SS);
-               OrigIStr = SS.str(););
-    LLVM_DEBUG(llvm::dbgs() << "SC: Visiting: " << OrigIStr << '\n');
-
     SILInstruction *currentInst = I;
     if (SILInstruction *Result = visit(I)) {
       ++NumCombined;

lib/SILOptimizer/SemanticARC/CopyValueOpts.cpp

@@ -69,6 +69,9 @@ using namespace swift::semanticarc;
 // TODO: This needs a better name.
 bool SemanticARCOptVisitor::performGuaranteedCopyValueOptimization(
     CopyValueInst *cvi) {
+  LLVM_DEBUG(llvm::dbgs() << "Looking at ");
+  LLVM_DEBUG(cvi->dump());
+
   // All mandatory copy optimization is handled by CanonicalizeOSSALifetime,
   // which knows how to preserve lifetimes for debugging.
   if (ctx.onlyMandatoryOpts)
@@ -82,8 +85,11 @@ bool SemanticARCOptVisitor::performGuaranteedCopyValueOptimization(
   //
   // NOTE: We can get multiple introducers if our copy_value's operand
   // value runs through a phi or an aggregate forming instruction.
-  if (!getAllBorrowIntroducingValues(cvi->getOperand(), borrowScopeIntroducers))
+  if (!getAllBorrowIntroducingValues(cvi->getOperand(),
+                                     borrowScopeIntroducers)) {
+    LLVM_DEBUG(llvm::dbgs() << "Did not find all borrow introducers\n");
     return false;
+  }
 
   // Then go over all of our uses and see if the value returned by our copy
   // value forms a dead live range or a live range that would be dead if it was
@@ -96,6 +102,7 @@ bool SemanticARCOptVisitor::performGuaranteedCopyValueOptimization(
       lr.hasUnknownConsumingUse(ctx.assumingAtFixedPoint);
   if (hasUnknownConsumingUseState ==
       OwnershipLiveRange::HasConsumingUse_t::Yes) {
+    LLVM_DEBUG(llvm::dbgs() << "Found unknown consuming uses\n");
     return false;
   }
 
@@ -192,6 +199,8 @@ bool SemanticARCOptVisitor::performGuaranteedCopyValueOptimization(
           return !borrowScope.areUsesWithinExtendedScope(
               lr.getAllConsumingUses(), nullptr);
         })) {
+      LLVM_DEBUG(llvm::dbgs() << "copy_value is extending borrow introducer "
+                                 "lifetime, bailing out\n");
       return false;
     }
   }

lib/SILOptimizer/Transforms/PerformanceInliner.cpp

@@ -1116,6 +1116,8 @@ bool SILPerformanceInliner::inlineCallsIntoFunction(SILFunction *Caller) {
   if (!Caller->shouldOptimize())
     return false;
 
+  LLVM_DEBUG(llvm::dbgs() << "Inlining calls into " << Caller->getName()
+                          << "\n");
   // First step: collect all the functions we want to inline.  We
   // don't change anything yet so that the dominator information
   // remains valid.
@@ -1143,6 +1145,8 @@ bool SILPerformanceInliner::inlineCallsIntoFunction(SILFunction *Caller) {
     // ownership... do not inline. The two modes are incompatible, so skip this
     // apply site for now.
     if (!Callee->hasOwnership() && Caller->hasOwnership()) {
+      LLVM_DEBUG(llvm::dbgs()
+                 << "Not inlining non-ossa " << Caller->getName() << "\n");
       continue;
     }