Have TableGen emit setSubgraphColor calls under control of a -gen-debug

flag.  Then in a debugger developers can set breakpoints at these calls
to see waht is about to be selected and what the resulting subgraph
looks like.  This really helps when debugging instruction selection.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58278 91177308-0d34-0410-b5e6-96231b3b80d8

11 files changed, 61 insertions, 16 deletions

diff --git a/include/llvm/CodeGen/DAGISelHeader.h b/include/llvm/CodeGen/DAGISelHeader.h
index 3542ebcbd0..e50ee7c00a 100644
--- a/include/llvm/CodeGen/DAGISelHeader.h
+++ b/include/llvm/CodeGen/DAGISelHeader.h
@@ -153,7 +153,7 @@ void ReplaceUses(SDNode *F, SDNode *T) DISABLE_INLINE {
 
 /// SelectRoot - Top level entry to DAG instruction selector.
 /// Selects instructions starting at the root of the current DAG.
-void SelectRoot() {
+void SelectRoot(SelectionDAG &DAG) {
   SelectRootInit();
   unsigned NumBytes = (DAGSize + 7) / 8;
   ISelQueued   = new unsigned char[NumBytes];
@@ -176,14 +176,18 @@ void SelectRoot() {
     // Skip already selected nodes.
     if (isSelected(Node->getNodeId()))
       continue;
+    DAG.setSubgraphColor(Node, "red");
     SDNode *ResNode = Select(SDValue(Node, 0));
     // If node should not be replaced, 
     // continue with the next one.
     if (ResNode == Node)
       continue;
     // Replace node.
-    if (ResNode)
+    if (ResNode) {
+      DAG.setSubgraphColor(ResNode, "yellow");
+      DAG.setSubgraphColor(ResNode, "black");
       ReplaceUses(Node, ResNode);
+    }
     // If after the replacement this node is not used any more,
     // remove this dead node.
     if (Node->use_empty()) { // Don't delete EntryToken, etc.
@@ -191,6 +195,7 @@ void SelectRoot() {
       CurDAG->RemoveDeadNode(Node, &ISQU);
       UpdateQueue(ISQU);
     }
+    //DAG.setSubgraphColor(Node, "black");
   }
 
   delete[] ISelQueued;
diff --git a/lib/Target/ARM/ARMISelDAGToDAG.cpp b/lib/Target/ARM/ARMISelDAGToDAG.cpp
index 560be0ad96..060f61ca70 100644
--- a/lib/Target/ARM/ARMISelDAGToDAG.cpp
+++ b/lib/Target/ARM/ARMISelDAGToDAG.cpp
@@ -94,7 +94,7 @@ public:
 void ARMDAGToDAGISel::InstructionSelect() {
   DEBUG(BB->dump());
 
-  SelectRoot();
+  SelectRoot(*CurDAG);
   CurDAG->RemoveDeadNodes();
 }
 
diff --git a/lib/Target/Alpha/AlphaISelDAGToDAG.cpp b/lib/Target/Alpha/AlphaISelDAGToDAG.cpp
index e4bd152885..e0ae5564ed 100644
--- a/lib/Target/Alpha/AlphaISelDAGToDAG.cpp
+++ b/lib/Target/Alpha/AlphaISelDAGToDAG.cpp
@@ -230,7 +230,7 @@ void AlphaDAGToDAGISel::InstructionSelect() {
   DEBUG(BB->dump());
   
   // Select target instructions for the DAG.
-  SelectRoot();
+  SelectRoot(*CurDAG);
   CurDAG->RemoveDeadNodes();
 }
 
diff --git a/lib/Target/CellSPU/SPUISelDAGToDAG.cpp b/lib/Target/CellSPU/SPUISelDAGToDAG.cpp
index 92c76af1d0..d6a492b575 100644
--- a/lib/Target/CellSPU/SPUISelDAGToDAG.cpp
+++ b/lib/Target/CellSPU/SPUISelDAGToDAG.cpp
@@ -344,7 +344,7 @@ SPUDAGToDAGISel::InstructionSelect()
   DEBUG(BB->dump());
 
   // Select target instructions for the DAG.
-  SelectRoot();
+  SelectRoot(*CurDAG);
   CurDAG->RemoveDeadNodes();
 }
 
diff --git a/lib/Target/IA64/IA64ISelDAGToDAG.cpp b/lib/Target/IA64/IA64ISelDAGToDAG.cpp
index 6d3199307e..ae59ea2489 100644
--- a/lib/Target/IA64/IA64ISelDAGToDAG.cpp
+++ b/lib/Target/IA64/IA64ISelDAGToDAG.cpp
@@ -97,7 +97,7 @@ void IA64DAGToDAGISel::InstructionSelect() {
   DEBUG(BB->dump());
 
   // Select target instructions for the DAG.
-  SelectRoot();
+  SelectRoot(*CurDAG);
   CurDAG->RemoveDeadNodes();
 }
 
diff --git a/lib/Target/Mips/MipsISelDAGToDAG.cpp b/lib/Target/Mips/MipsISelDAGToDAG.cpp
index 2e3756a871..b31bcbdc0b 100644
--- a/lib/Target/Mips/MipsISelDAGToDAG.cpp
+++ b/lib/Target/Mips/MipsISelDAGToDAG.cpp
@@ -105,7 +105,7 @@ InstructionSelect()
   #endif
 
   // Select target instructions for the DAG.
-  SelectRoot();
+  SelectRoot(*CurDAG);
 
   #ifndef NDEBUG
   DOUT << "===== Instruction selection ends:\n";
diff --git a/lib/Target/PIC16/PIC16ISelDAGToDAG.cpp b/lib/Target/PIC16/PIC16ISelDAGToDAG.cpp
index 4d06089e9c..d98be99f86 100644
--- a/lib/Target/PIC16/PIC16ISelDAGToDAG.cpp
+++ b/lib/Target/PIC16/PIC16ISelDAGToDAG.cpp
@@ -102,7 +102,7 @@ void PIC16DAGToDAGISel::InstructionSelect()
 #endif
 
   // Select target instructions for the DAG.
-  SelectRoot();
+  SelectRoot(*CurDAG);
 
   DOUT << "===== Instruction selection ends:\n";
 
diff --git a/lib/Target/PowerPC/PPCISelDAGToDAG.cpp b/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
index e2ffb31fcc..37ca2be85d 100644
--- a/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
+++ b/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
@@ -204,7 +204,7 @@ void PPCDAGToDAGISel::InstructionSelect() {
   DEBUG(BB->dump());
 
   // Select target instructions for the DAG.
-  SelectRoot();
+  SelectRoot(*CurDAG);
   CurDAG->RemoveDeadNodes();
 }
 
diff --git a/lib/Target/Sparc/SparcISelDAGToDAG.cpp b/lib/Target/Sparc/SparcISelDAGToDAG.cpp
index 66e143de3f..ceba75d788 100644
--- a/lib/Target/Sparc/SparcISelDAGToDAG.cpp
+++ b/lib/Target/Sparc/SparcISelDAGToDAG.cpp
@@ -70,7 +70,7 @@ void SparcDAGToDAGISel::InstructionSelect() {
   DEBUG(BB->dump());
 
   // Select target instructions for the DAG.
-  SelectRoot();
+  SelectRoot(*CurDAG);
   CurDAG->RemoveDeadNodes();
 }
 
diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index 6735f1d80b..c341980978 100644
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -655,7 +655,7 @@ void X86DAGToDAGISel::InstructionSelect() {
   DOUT << "===== Instruction selection begins:\n";
   Indent = 0;
 #endif
-  SelectRoot();
+  SelectRoot(*CurDAG);
 #ifndef NDEBUG
   DOUT << "===== Instruction selection ends:\n";
 #endif
diff --git a/utils/TableGen/DAGISelEmitter.cpp b/utils/TableGen/DAGISelEmitter.cpp
index 299612977a..82d414884b 100644
--- a/utils/TableGen/DAGISelEmitter.cpp
+++ b/utils/TableGen/DAGISelEmitter.cpp
@@ -14,13 +14,21 @@
 #include "DAGISelEmitter.h"
 #include "Record.h"
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/MathExtras.h"
+#include "llvm/Support/Debug.h"
 #include "llvm/Support/Streams.h"
 #include <algorithm>
 #include <deque>
 using namespace llvm;
 
+namespace {
+  cl::opt<bool>
+  GenDebug("gen-debug", cl::desc("Generate debug code"),
+              cl::init(false));
+}
+
 //===----------------------------------------------------------------------===//
 // DAGISelEmitter Helper methods
 //
@@ -969,6 +977,10 @@ public:
         emitCode("InChains.push_back(" + ChainName + ");");
         emitCode(ChainName + " = CurDAG->getNode(ISD::TokenFactor, MVT::Other, "
                  "&InChains[0], InChains.size());");
+        if (GenDebug) {
+          emitCode("CurDAG->setSubgraphColor(" + ChainName +".getNode(), \"yellow\");");
+          emitCode("CurDAG->setSubgraphColor(" + ChainName +".getNode(), \"black\");");
+        }
       }
 
       // Loop over all of the operands of the instruction pattern, emitting code
@@ -1096,13 +1108,18 @@ public:
       if (II.isSimpleLoad | II.mayLoad | II.mayStore) {
         std::vector<std::string>::const_iterator mi, mie;
         for (mi = LSI.begin(), mie = LSI.end(); mi != mie; ++mi) {
-          emitCode("SDValue LSI_" + *mi + " = "
+          std::string LSIName = "LSI_" + *mi;
+          emitCode("SDValue " + LSIName + " = "
                    "CurDAG->getMemOperand(cast<MemSDNode>(" +
                    *mi + ")->getMemOperand());");
+          if (GenDebug) {
+            emitCode("CurDAG->setSubgraphColor(" + LSIName +".getNode(), \"yellow\");");
+            emitCode("CurDAG->setSubgraphColor(" + LSIName +".getNode(), \"black\");");
+          }
           if (IsVariadic)
-            emitCode("Ops" + utostr(OpsNo) + ".push_back(LSI_" + *mi + ");");
+            emitCode("Ops" + utostr(OpsNo) + ".push_back(" + LSIName + ");");
           else
-            AllOps.push_back("LSI_" + *mi);
+            AllOps.push_back(LSIName);
         }
       }
 
@@ -1269,6 +1286,18 @@ public:
       }
 
       emitCode(CodePrefix + Code + ");");
+
+      if (GenDebug) {
+        if (!isRoot) {
+          emitCode("CurDAG->setSubgraphColor(" + NodeName +".getNode(), \"yellow\");");
+          emitCode("CurDAG->setSubgraphColor(" + NodeName +".getNode(), \"black\");");
+        }
+        else {
+          emitCode("CurDAG->setSubgraphColor(" + NodeName +", \"yellow\");");
+          emitCode("CurDAG->setSubgraphColor(" + NodeName +", \"black\");");
+        }
+      }
+
       for (unsigned i = 0, e = After.size(); i != e; ++i)
         emitCode(After[i]);
 
@@ -1766,8 +1795,19 @@ void DAGISelEmitter::EmitInstructionSelector(std::ostream &OS) {
 
         // Replace the emission code within selection routines with calls to the
         // emission functions.
-        CallerCode = "return Emit_" + utostr(EmitFuncNum) + CallerCode;
-        GeneratedCode.push_back(std::make_pair(false, CallerCode));
+        if (GenDebug) {
+          GeneratedCode.push_back(std::make_pair(0, "CurDAG->setSubgraphColor(N.getNode(), \"red\");"));
+        }
+        CallerCode = "SDNode *Result = Emit_" + utostr(EmitFuncNum) + CallerCode;
+        GeneratedCode.push_back(std::make_pair(3, CallerCode));
+        if (GenDebug) {
+          GeneratedCode.push_back(std::make_pair(0, "if(Result) {"));
+          GeneratedCode.push_back(std::make_pair(0, "  CurDAG->setSubgraphColor(Result, \"yellow\");"));
+          GeneratedCode.push_back(std::make_pair(0, "  CurDAG->setSubgraphColor(Result, \"black\");"));
+          GeneratedCode.push_back(std::make_pair(0, "}"));
+          //GeneratedCode.push_back(std::make_pair(0, "CurDAG->setSubgraphColor(N.getNode(), \"black\");"));
+        }
+        GeneratedCode.push_back(std::make_pair(0, "return Result;"));
       }
 
       // Print function.