Move support/tools/* back into utils

llvm-svn: 8875

1 files changed, 217 insertions, 0 deletions

diff --git a/llvm/utils/TableGen/CodeEmitterGen.cpp b/llvm/utils/TableGen/CodeEmitterGen.cpp
new file mode 100644
index 00000000000..98976c73363
--- /dev/null
+++ b/llvm/utils/TableGen/CodeEmitterGen.cpp
@@ -0,0 +1,217 @@
+//===- CodeEmitterGen.cpp - Code Emitter Generator ------------------------===//
+//
+// FIXME: Document.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CodeEmitterGen.h"
+#include "Record.h"
+#include "Support/Debug.h"
+
+void CodeEmitterGen::run(std::ostream &o) {
+  std::vector<Record*> Insts = Records.getAllDerivedDefinitions("Instruction");
+
+  EmitSourceFileHeader("Machine Code Emitter", o);
+
+  std::string Namespace = "V9::";
+  std::string ClassName = "SparcV9CodeEmitter::";
+
+  //const std::string &Namespace = Inst->getValue("Namespace")->getName();
+  o << "unsigned " << ClassName
+    << "getBinaryCodeForInstr(MachineInstr &MI) {\n"
+    << "  unsigned Value = 0;\n"
+    << "  DEBUG(std::cerr << MI);\n"
+    << "  switch (MI.getOpcode()) {\n";
+  for (std::vector<Record*>::iterator I = Insts.begin(), E = Insts.end();
+       I != E; ++I) {
+    Record *R = *I;
+    o << "    case " << Namespace << R->getName() << ": {\n"
+      << "      DEBUG(std::cerr << \"Emitting " << R->getName() << "\\n\");\n";
+
+    BitsInit *BI = R->getValueAsBitsInit("Inst");
+
+    unsigned Value = 0;
+    const std::vector<RecordVal> &Vals = R->getValues();
+
+    DEBUG(o << "      // prefilling: ");
+    // Start by filling in fixed values...
+    for (unsigned i = 0, e = BI->getNumBits(); i != e; ++i) {
+      if (BitInit *B = dynamic_cast<BitInit*>(BI->getBit(e-i-1))) {
+        Value |= B->getValue() << (e-i-1);
+        DEBUG(o << B->getValue());
+      } else {
+        DEBUG(o << "0");
+      }
+    }
+    DEBUG(o << "\n");
+
+    DEBUG(o << "      // " << *R->getValue("Inst") << "\n");
+    o << "      Value = " << Value << "U;\n\n";
+    
+    // Loop over all of the fields in the instruction determining which are the
+    // operands to the instruction. 
+    //
+    unsigned op = 0;
+    std::map<std::string, unsigned> OpOrder;
+    std::map<std::string, bool> OpContinuous;
+    for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
+      if (!Vals[i].getPrefix() &&  !Vals[i].getValue()->isComplete()) {
+        // Is the operand continuous? If so, we can just mask and OR it in
+        // instead of doing it bit-by-bit, saving a lot in runtime cost.        
+        const BitsInit *InstInit = BI;
+        int beginBitInVar = -1, endBitInVar = -1;
+        int beginBitInInst = -1, endBitInInst = -1;
+        bool continuous = true;
+
+        for (int bit = InstInit->getNumBits()-1; bit >= 0; --bit) {
+          if (VarBitInit *VBI =
+              dynamic_cast<VarBitInit*>(InstInit->getBit(bit))) {
+            TypedInit *TI = VBI->getVariable();
+            if (VarInit *VI = dynamic_cast<VarInit*>(TI)) {
+              // only process the current variable
+              if (VI->getName() != Vals[i].getName())
+                continue;
+
+              if (beginBitInVar == -1)
+                beginBitInVar = VBI->getBitNum();
+
+              if (endBitInVar == -1)
+                endBitInVar = VBI->getBitNum();
+              else {
+                if (endBitInVar == (int)VBI->getBitNum() + 1)
+                  endBitInVar = VBI->getBitNum();
+                else {
+                  continuous = false;
+                  break;
+                }
+              }
+
+              if (beginBitInInst == -1)
+                beginBitInInst = bit;
+              if (endBitInInst == -1)
+                endBitInInst = bit;
+              else {
+                if (endBitInInst == bit + 1)
+                  endBitInInst = bit;
+                else {
+                  continuous = false;
+                  break;
+                }
+              }
+
+              // maintain same distance between bits in field and bits in
+              // instruction. if the relative distances stay the same
+              // throughout,
+              if (beginBitInVar - (int)VBI->getBitNum() !=
+                  beginBitInInst - bit) {
+                continuous = false;
+                break;
+              }
+            }
+          }
+        }
+
+        // If we have found no bit in "Inst" which comes from this field, then
+        // this is not an operand!!
+        if (beginBitInInst != -1) {
+          o << "      // op" << op << ": " << Vals[i].getName() << "\n"
+            << "      int64_t op" << op 
+            <<" = getMachineOpValue(MI, MI.getOperand("<<op<<"));\n";
+          //<< "   MachineOperand &op" << op <<" = MI.getOperand("<<op<<");\n";
+          OpOrder[Vals[i].getName()] = op++;
+          
+          DEBUG(o << "      // Var: begin = " << beginBitInVar 
+                  << ", end = " << endBitInVar
+                  << "; Inst: begin = " << beginBitInInst
+                  << ", end = " << endBitInInst << "\n");
+          
+          if (continuous) {
+            DEBUG(o << "      // continuous: op" << OpOrder[Vals[i].getName()]
+                    << "\n");
+            
+            // Mask off the right bits
+            // Low mask (ie. shift, if necessary)
+            assert(endBitInVar >= 0 && "Negative shift amount in masking!");
+            if (endBitInVar != 0) {
+              o << "      op" << OpOrder[Vals[i].getName()]
+                << " >>= " << endBitInVar << ";\n";
+              beginBitInVar -= endBitInVar;
+              endBitInVar = 0;
+            }
+            
+            // High mask
+            o << "      op" << OpOrder[Vals[i].getName()]
+              << " &= (1<<" << beginBitInVar+1 << ") - 1;\n";
+            
+            // Shift the value to the correct place (according to place in inst)
+            assert(endBitInInst >= 0 && "Negative shift amount in inst position!");
+            if (endBitInInst != 0)
+              o << "      op" << OpOrder[Vals[i].getName()]
+              << " <<= " << endBitInInst << ";\n";
+            
+            // Just OR in the result
+            o << "      Value |= op" << OpOrder[Vals[i].getName()] << ";\n";
+          }
+          
+          // otherwise, will be taken care of in the loop below using this
+          // value:
+          OpContinuous[Vals[i].getName()] = continuous;
+        }
+      }
+    }
+
+    for (unsigned f = 0, e = Vals.size(); f != e; ++f) {
+      if (Vals[f].getPrefix()) {
+        BitsInit *FieldInitializer = (BitsInit*)Vals[f].getValue();
+
+        // Scan through the field looking for bit initializers of the current
+        // variable...
+        for (int i = FieldInitializer->getNumBits()-1; i >= 0; --i) {
+          if (BitInit *BI = dynamic_cast<BitInit*>(FieldInitializer->getBit(i)))
+          {
+            DEBUG(o << "      // bit init: f: " << f << ", i: " << i << "\n");
+          } else if (UnsetInit *UI =
+                     dynamic_cast<UnsetInit*>(FieldInitializer->getBit(i))) {
+            DEBUG(o << "      // unset init: f: " << f << ", i: " << i << "\n");
+          } else if (VarBitInit *VBI =
+                     dynamic_cast<VarBitInit*>(FieldInitializer->getBit(i))) {
+            TypedInit *TI = VBI->getVariable();
+            if (VarInit *VI = dynamic_cast<VarInit*>(TI)) {
+              // If the bits of the field are laid out consecutively in the
+              // instruction, then instead of separately ORing in bits, just
+              // mask and shift the entire field for efficiency.
+              if (OpContinuous[VI->getName()]) {
+                // already taken care of in the loop above, thus there is no
+                // need to individually OR in the bits
+
+                // for debugging, output the regular version anyway, commented
+                DEBUG(o << "      // Value |= getValueBit(op"
+                        << OpOrder[VI->getName()] << ", " << VBI->getBitNum()
+                        << ")" << " << " << i << ";\n");
+              } else {
+                o << "      Value |= getValueBit(op" << OpOrder[VI->getName()]
+                  << ", " << VBI->getBitNum()
+                  << ")" << " << " << i << ";\n";
+              }
+            } else if (FieldInit *FI = dynamic_cast<FieldInit*>(TI)) {
+              // FIXME: implement this!
+              o << "FIELD INIT not implemented yet!\n";
+            } else {
+              o << "Error: UNIMPLEMENTED\n";
+            }
+          }
+        }
+      }
+    }
+
+    o << "      break;\n"
+      << "    }\n";
+  }
+
+  o << "  default:\n"
+    << "    std::cerr << \"Not supported instr: \" << MI << \"\\n\";\n"
+    << "    abort();\n"
+    << "  }\n"
+    << "  return Value;\n"
+    << "}\n";
+}