Print indices of assertions instead of raw bitsets (#54928)

* Add JITDUMPEXEC macro

For use in contexts where some printing method
should only be executed when "verbose" is true.

* Add helpers for printing assertion indexes

* Print assertion indices instead of raw bitsets

To aid in understanding what assertions are being
propagated and merged when reading the dumps.

* Don't print VNs for the same assertion twice

* Also correctly print VNs in CopyProp

* Align "in"s with "out"s for final assertions

* Don't print the assertion dataflow in usual dumps

It can still be enabled if needed.

5 files changed, 160 insertions, 54 deletions

diff --git a/src/coreclr/jit/assertionprop.cpp b/src/coreclr/jit/assertionprop.cpp
index 981879142bf..fb869c89fee 100644
--- a/src/coreclr/jit/assertionprop.cpp
+++ b/src/coreclr/jit/assertionprop.cpp
@@ -558,7 +558,7 @@ void Compiler::optAssertionInit(bool isLocalProp)
 }
 
 #ifdef DEBUG
-void Compiler::optPrintAssertion(AssertionDsc* curAssertion, AssertionIndex assertionIndex /* =0 */)
+void Compiler::optPrintAssertion(AssertionDsc* curAssertion, AssertionIndex assertionIndex /* = 0 */)
 {
     if (curAssertion->op1.kind == O1K_EXACT_TYPE)
     {
@@ -590,10 +590,6 @@ void Compiler::optPrintAssertion(AssertionDsc* curAssertion, AssertionIndex asse
         printf("?assertion classification? ");
     }
     printf("Assertion: ");
-    if (!optLocalAssertionProp)
-    {
-        printf("(%d, %d) ", curAssertion->op1.vn, curAssertion->op2.vn);
-    }
 
     if (!optLocalAssertionProp)
     {
@@ -778,12 +774,67 @@ void Compiler::optPrintAssertion(AssertionDsc* curAssertion, AssertionIndex asse
 
     if (assertionIndex > 0)
     {
-        printf(" index=#%02u, mask=", assertionIndex);
-        printf("%s", BitVecOps::ToString(apTraits, BitVecOps::MakeSingleton(apTraits, assertionIndex - 1)));
+        printf(", index = ");
+        optPrintAssertionIndex(assertionIndex);
     }
     printf("\n");
 }
+
+void Compiler::optPrintAssertionIndex(AssertionIndex index)
+{
+    if (index == NO_ASSERTION_INDEX)
+    {
+        printf("#NA");
+        return;
+    }
+
+    printf("#%02u", index);
+}
+
+void Compiler::optPrintAssertionIndices(ASSERT_TP assertions)
+{
+    if (BitVecOps::IsEmpty(apTraits, assertions))
+    {
+        optPrintAssertionIndex(NO_ASSERTION_INDEX);
+        return;
+    }
+
+    BitVecOps::Iter iter(apTraits, assertions);
+    unsigned        bitIndex = 0;
+    if (iter.NextElem(&bitIndex))
+    {
+        optPrintAssertionIndex(static_cast<AssertionIndex>(bitIndex + 1));
+        while (iter.NextElem(&bitIndex))
+        {
+            printf(" ");
+            optPrintAssertionIndex(static_cast<AssertionIndex>(bitIndex + 1));
+        }
+    }
+}
+#endif // DEBUG
+
+/* static */
+void Compiler::optDumpAssertionIndices(const char* header, ASSERT_TP assertions, const char* footer /* = nullptr */)
+{
+#ifdef DEBUG
+    Compiler* compiler = JitTls::GetCompiler();
+    if (compiler->verbose)
+    {
+        printf(header);
+        compiler->optPrintAssertionIndices(assertions);
+        if (footer != nullptr)
+        {
+            printf(footer);
+        }
+    }
 #endif // DEBUG
+}
+
+/* static */
+void Compiler::optDumpAssertionIndices(ASSERT_TP assertions, const char* footer /* = nullptr */)
+{
+    optDumpAssertionIndices("", assertions, footer);
+}
 
 /******************************************************************************
  *
@@ -4511,7 +4562,7 @@ void Compiler::optImpliedByConstAssertion(AssertionDsc* constAssertion, ASSERT_T
             if (verbose)
             {
                 AssertionDsc* firstAssertion = optGetAssertion(1);
-                printf("\nCompiler::optImpliedByConstAssertion: constAssertion #%02d , implies assertion #%02d",
+                printf("Compiler::optImpliedByConstAssertion: const assertion #%02d implies assertion #%02d\n",
                        (constAssertion - firstAssertion) + 1, (impAssertion - firstAssertion) + 1);
             }
 #endif
@@ -4721,8 +4772,12 @@ public:
     // At the start of the merge function of the dataflow equations, initialize premerge state (to detect change.)
     void StartMerge(BasicBlock* block)
     {
-        JITDUMP("AssertionPropCallback::StartMerge: " FMT_BB " in -> %s\n", block->bbNum,
-                BitVecOps::ToString(apTraits, block->bbAssertionIn));
+        if (VerboseDataflow())
+        {
+            JITDUMP("StartMerge: " FMT_BB " ", block->bbNum);
+            Compiler::optDumpAssertionIndices("in -> ", block->bbAssertionIn, "\n");
+        }
+
         BitVecOps::Assign(apTraits, preMergeOut, block->bbAssertionOut);
         BitVecOps::Assign(apTraits, preMergeJumpDestOut, mJumpDestOut[block->bbNum]);
     }
@@ -4743,11 +4798,14 @@ public:
                 assert(predBlock->bbNext == block);
                 BitVecOps::IntersectionD(apTraits, pAssertionOut, predBlock->bbAssertionOut);
 
-                JITDUMP("AssertionPropCallback::Merge     : Duplicate flow, " FMT_BB " in -> %s, predBlock " FMT_BB
-                        " out1 -> %s, out2 -> %s\n",
-                        block->bbNum, BitVecOps::ToString(apTraits, block->bbAssertionIn), predBlock->bbNum,
-                        BitVecOps::ToString(apTraits, mJumpDestOut[predBlock->bbNum]),
-                        BitVecOps::ToString(apTraits, predBlock->bbAssertionOut));
+                if (VerboseDataflow())
+                {
+                    JITDUMP("Merge     : Duplicate flow, " FMT_BB " ", block->bbNum);
+                    Compiler::optDumpAssertionIndices("in -> ", block->bbAssertionIn, "; ");
+                    JITDUMP("pred " FMT_BB " ", predBlock->bbNum);
+                    Compiler::optDumpAssertionIndices("out1 -> ", mJumpDestOut[predBlock->bbNum], "; ");
+                    Compiler::optDumpAssertionIndices("out2 -> ", predBlock->bbAssertionOut, "\n");
+                }
             }
         }
         else
@@ -4755,9 +4813,14 @@ public:
             pAssertionOut = predBlock->bbAssertionOut;
         }
 
-        JITDUMP("AssertionPropCallback::Merge     : " FMT_BB " in -> %s, predBlock " FMT_BB " out -> %s\n",
-                block->bbNum, BitVecOps::ToString(apTraits, block->bbAssertionIn), predBlock->bbNum,
-                BitVecOps::ToString(apTraits, pAssertionOut));
+        if (VerboseDataflow())
+        {
+            JITDUMP("Merge     : " FMT_BB " ", block->bbNum);
+            Compiler::optDumpAssertionIndices("in -> ", block->bbAssertionIn, "; ");
+            JITDUMP("pred " FMT_BB " ", predBlock->bbNum);
+            Compiler::optDumpAssertionIndices("out -> ", pAssertionOut, "\n");
+        }
+
         BitVecOps::IntersectionD(apTraits, block->bbAssertionIn, pAssertionOut);
     }
 
@@ -4781,8 +4844,11 @@ public:
     // At the end of the merge store results of the dataflow equations, in a postmerge state.
     bool EndMerge(BasicBlock* block)
     {
-        JITDUMP("AssertionPropCallback::EndMerge  : " FMT_BB " in -> %s\n\n", block->bbNum,
-                BitVecOps::ToString(apTraits, block->bbAssertionIn));
+        if (VerboseDataflow())
+        {
+            JITDUMP("EndMerge  : " FMT_BB " ", block->bbNum);
+            Compiler::optDumpAssertionIndices("in -> ", block->bbAssertionIn, "\n\n");
+        }
 
         BitVecOps::DataFlowD(apTraits, block->bbAssertionOut, block->bbAssertionGen, block->bbAssertionIn);
         BitVecOps::DataFlowD(apTraits, mJumpDestOut[block->bbNum], mJumpDestGen[block->bbNum], block->bbAssertionIn);
@@ -4790,24 +4856,35 @@ public:
         bool changed = (!BitVecOps::Equal(apTraits, preMergeOut, block->bbAssertionOut) ||
                         !BitVecOps::Equal(apTraits, preMergeJumpDestOut, mJumpDestOut[block->bbNum]));
 
-        if (changed)
-        {
-            JITDUMP("AssertionPropCallback::Changed   : " FMT_BB " before out -> %s; after out -> %s;\n"
-                    "\t\tjumpDest before out -> %s; jumpDest after out -> %s;\n\n",
-                    block->bbNum, BitVecOps::ToString(apTraits, preMergeOut),
-                    BitVecOps::ToString(apTraits, block->bbAssertionOut),
-                    BitVecOps::ToString(apTraits, preMergeJumpDestOut),
-                    BitVecOps::ToString(apTraits, mJumpDestOut[block->bbNum]));
-        }
-        else
+        if (VerboseDataflow())
         {
-            JITDUMP("AssertionPropCallback::Unchanged  : " FMT_BB " out -> %s; \t\tjumpDest out -> %s\n\n",
-                    block->bbNum, BitVecOps::ToString(apTraits, block->bbAssertionOut),
-                    BitVecOps::ToString(apTraits, mJumpDestOut[block->bbNum]));
+            if (changed)
+            {
+                JITDUMP("Changed   : " FMT_BB " ", block->bbNum);
+                Compiler::optDumpAssertionIndices("before out -> ", preMergeOut, "; ");
+                Compiler::optDumpAssertionIndices("after out -> ", block->bbAssertionOut, ";\n        ");
+                Compiler::optDumpAssertionIndices("jumpDest before out -> ", preMergeJumpDestOut, "; ");
+                Compiler::optDumpAssertionIndices("jumpDest after out -> ", mJumpDestOut[block->bbNum], ";\n\n");
+            }
+            else
+            {
+                JITDUMP("Unchanged : " FMT_BB " ", block->bbNum);
+                Compiler::optDumpAssertionIndices("out -> ", block->bbAssertionOut, "; ");
+                Compiler::optDumpAssertionIndices("jumpDest out -> ", mJumpDestOut[block->bbNum], "\n\n");
+            }
         }
 
         return changed;
     }
+
+    // Can be enabled to get detailed debug output about dataflow for assertions.
+    bool VerboseDataflow()
+    {
+#if 0
+        return VERBOSE;
+#endif
+        return false;
+    }
 };
 
 /*****************************************************************************
@@ -4894,16 +4971,28 @@ ASSERT_TP* Compiler::optComputeAssertionGen()
 #ifdef DEBUG
         if (verbose)
         {
-            printf(FMT_BB " valueGen = %s", block->bbNum, BitVecOps::ToString(apTraits, block->bbAssertionGen));
+            if (block == fgFirstBB)
+            {
+                printf("\n");
+            }
+
+            printf(FMT_BB " valueGen = ", block->bbNum);
+            optPrintAssertionIndices(block->bbAssertionGen);
             if (block->bbJumpKind == BBJ_COND)
             {
-                printf(" => " FMT_BB " valueGen = %s,", block->bbJumpDest->bbNum,
-                       BitVecOps::ToString(apTraits, jumpDestGen[block->bbNum]));
+                printf(" => " FMT_BB " valueGen = ", block->bbJumpDest->bbNum);
+                optPrintAssertionIndices(jumpDestGen[block->bbNum]);
             }
             printf("\n");
+
+            if (block == fgLastBB)
+            {
+                printf("\n");
+            }
         }
 #endif
     }
+
     return jumpDestGen;
 }
 
@@ -5408,6 +5497,10 @@ void Compiler::optAssertionPropMain()
     // Modified dataflow algorithm for available expressions.
     DataFlow                  flow(this);
     AssertionPropFlowCallback ap(this, bbJtrueAssertionOut, jumpDestGen);
+    if (ap.VerboseDataflow())
+    {
+        JITDUMP("AssertionPropFlowCallback:\n\n")
+    }
     flow.ForwardAnalysis(ap);
 
     for (BasicBlock* const block : Blocks())
@@ -5419,16 +5512,15 @@ void Compiler::optAssertionPropMain()
 #ifdef DEBUG
     if (verbose)
     {
-        printf("\n");
         for (BasicBlock* const block : Blocks())
         {
-            printf("\n" FMT_BB, block->bbNum);
-            printf(" valueIn  = %s", BitVecOps::ToString(apTraits, block->bbAssertionIn));
-            printf(" valueOut = %s", BitVecOps::ToString(apTraits, block->bbAssertionOut));
+            printf(FMT_BB ":\n", block->bbNum);
+            optDumpAssertionIndices(" in   = ", block->bbAssertionIn, "\n");
+            optDumpAssertionIndices(" out  = ", block->bbAssertionOut, "\n");
             if (block->bbJumpKind == BBJ_COND)
             {
-                printf(" => " FMT_BB, block->bbJumpDest->bbNum);
-                printf(" valueOut= %s", BitVecOps::ToString(apTraits, bbJtrueAssertionOut[block->bbNum]));
+                printf(" " FMT_BB " = ", block->bbJumpDest->bbNum);
+                optDumpAssertionIndices(bbJtrueAssertionOut[block->bbNum], "\n");
             }
         }
         printf("\n");
@@ -5473,9 +5565,11 @@ void Compiler::optAssertionPropMain()
                                                        // and thus we must morph, set order, re-link
             for (GenTree* tree = stmt->GetTreeList(); tree != nullptr; tree = tree->gtNext)
             {
-                JITDUMP("Propagating %s assertions for " FMT_BB ", stmt " FMT_STMT ", tree [%06d], tree -> %d\n",
-                        BitVecOps::ToString(apTraits, assertions), block->bbNum, stmt->GetID(), dspTreeID(tree),
-                        tree->GetAssertionInfo().GetAssertionIndex());
+                optDumpAssertionIndices("Propagating ", assertions, " ");
+                JITDUMP("for " FMT_BB ", stmt " FMT_STMT ", tree [%06d]", block->bbNum, stmt->GetID(), dspTreeID(tree));
+                JITDUMP(", tree -> ");
+                JITDUMPEXEC(optPrintAssertionIndex(tree->GetAssertionInfo().GetAssertionIndex()));
+                JITDUMP("\n");
 
                 GenTree* newTree = optAssertionProp(assertions, tree, stmt, block);
                 if (newTree)
diff --git a/src/coreclr/jit/compiler.h b/src/coreclr/jit/compiler.h
index 356fe6498d1..639b67bb15c 100644
--- a/src/coreclr/jit/compiler.h
+++ b/src/coreclr/jit/compiler.h
@@ -7491,9 +7491,14 @@ public:
 
 #ifdef DEBUG
     void optPrintAssertion(AssertionDsc* newAssertion, AssertionIndex assertionIndex = 0);
+    void optPrintAssertionIndex(AssertionIndex index);
+    void optPrintAssertionIndices(ASSERT_TP assertions);
     void optDebugCheckAssertion(AssertionDsc* assertion);
     void optDebugCheckAssertions(AssertionIndex AssertionIndex);
 #endif
+    static void optDumpAssertionIndices(const char* header, ASSERT_TP assertions, const char* footer = nullptr);
+    static void optDumpAssertionIndices(ASSERT_TP assertions, const char* footer = nullptr);
+
     void optAddCopies();
 #endif // ASSERTION_PROP
 
diff --git a/src/coreclr/jit/copyprop.cpp b/src/coreclr/jit/copyprop.cpp
index c0d72123e1a..625e2eee5e8 100644
--- a/src/coreclr/jit/copyprop.cpp
+++ b/src/coreclr/jit/copyprop.cpp
@@ -270,9 +270,9 @@ void Compiler::optCopyProp(BasicBlock* block, Statement* stmt, GenTree* tree, Lc
         {
             JITDUMP("VN based copy assertion for ");
             printTreeID(tree);
-            printf(" V%02d @%08X by ", lclNum, tree->GetVN(VNK_Conservative));
+            printf(" V%02d " FMT_VN " by ", lclNum, tree->GetVN(VNK_Conservative));
             printTreeID(op);
-            printf(" V%02d @%08X.\n", newLclNum, op->GetVN(VNK_Conservative));
+            printf(" V%02d " FMT_VN ".\n", newLclNum, op->GetVN(VNK_Conservative));
             gtDispTree(tree, nullptr, nullptr, true);
         }
 #endif
diff --git a/src/coreclr/jit/jit.h b/src/coreclr/jit/jit.h
index 2dd39559c28..fb39fda019c 100644
--- a/src/coreclr/jit/jit.h
+++ b/src/coreclr/jit/jit.h
@@ -487,6 +487,11 @@ const bool dspGCtbls = true;
         if (JitTls::GetCompiler()->verbose)                                                                            \
             logf(__VA_ARGS__);                                                                                         \
     }
+#define JITDUMPEXEC(x)                                                                                                 \
+    {                                                                                                                  \
+        if (JitTls::GetCompiler()->verbose)                                                                            \
+            x;                                                                                                         \
+    }
 #define JITLOG(x)                                                                                                      \
     {                                                                                                                  \
         JitLogEE x;                                                                                                    \
@@ -521,6 +526,7 @@ const bool dspGCtbls = true;
 #define VERBOSE JitTls::GetCompiler()->verbose
 #else // !DEBUG
 #define JITDUMP(...)
+#define JITDUMPEXEC(x)
 #define JITLOG(x)
 #define JITLOG_THIS(t, x)
 #define DBEXEC(flg, expr)
diff --git a/src/coreclr/jit/rangecheck.cpp b/src/coreclr/jit/rangecheck.cpp
index 5c95b91883c..a37f11cedae 100644
--- a/src/coreclr/jit/rangecheck.cpp
+++ b/src/coreclr/jit/rangecheck.cpp
@@ -865,16 +865,16 @@ void RangeCheck::MergeAssertion(BasicBlock* block, GenTree* op, Range* pRange DE
         if (pred->bbFallsThrough() && pred->bbNext == block)
         {
             assertions = pred->bbAssertionOut;
-            JITDUMP("Merge assertions from pred " FMT_BB " edge: %s\n", pred->bbNum,
-                    BitVecOps::ToString(m_pCompiler->apTraits, assertions));
+            JITDUMP("Merge assertions from pred " FMT_BB " edge: ", pred->bbNum);
+            Compiler::optDumpAssertionIndices(assertions, "\n");
         }
         else if ((pred->bbJumpKind == BBJ_COND || pred->bbJumpKind == BBJ_ALWAYS) && pred->bbJumpDest == block)
         {
             if (m_pCompiler->bbJtrueAssertionOut != nullptr)
             {
                 assertions = m_pCompiler->bbJtrueAssertionOut[pred->bbNum];
-                JITDUMP("Merge assertions from pred " FMT_BB " JTrue edge: %s\n", pred->bbNum,
-                        BitVecOps::ToString(m_pCompiler->apTraits, assertions));
+                JITDUMP("Merge assertions from pred " FMT_BB " JTrue edge: ", pred->bbNum);
+                Compiler::optDumpAssertionIndices(assertions, "\n");
             }
         }
     }
@@ -1012,9 +1012,10 @@ Range RangeCheck::ComputeRangeForLocalDef(BasicBlock*          block,
     Range range = GetRange(ssaDef->GetBlock(), ssaDef->GetAssignment()->gtGetOp2(), monIncreasing DEBUGARG(indent));
     if (!BitVecOps::MayBeUninit(block->bbAssertionIn) && (m_pCompiler->GetAssertionCount() > 0))
     {
-        JITDUMP("Merge assertions from " FMT_BB ":%s for assignment about [%06d]\n", block->bbNum,
-                BitVecOps::ToString(m_pCompiler->apTraits, block->bbAssertionIn),
-                Compiler::dspTreeID(ssaDef->GetAssignment()->gtGetOp1()));
+        JITDUMP("Merge assertions from " FMT_BB ": ", block->bbNum);
+        Compiler::optDumpAssertionIndices(block->bbAssertionIn, " ");
+        JITDUMP("for assignment about [%06d]\n", Compiler::dspTreeID(ssaDef->GetAssignment()->gtGetOp1()))
+
         MergeEdgeAssertions(ssaDef->GetAssignment()->gtGetOp1()->AsLclVarCommon(), block->bbAssertionIn, &range);
         JITDUMP("done merging\n");
     }