PTX backend implementation for HAT

hat/backends/ptx/src/main/java/hat/backend/PTXBackend.java

@@ -77,8 +77,6 @@ public void dispatchKernel(KernelCallGraph kernelCallGraph, NDRange ndRange, Obj
 
         System.out.println("Entrypoint ->"+kernelCallGraph.entrypoint.method.getName());
         String code = createCode(kernelCallGraph, new PTXCodeBuilder(), args);
-        // System.out.println("\nCode Builder Output: \n\n" + code);
-        // System.out.println("Add your code to "+PTXBackend.class.getName()+".dispatchKernel() to actually run! :)");
         long programHandle = compileProgram(code);
         if (programOK(programHandle)) {
             long kernelHandle = getKernel(programHandle, kernelCallGraph.entrypoint.method.getName());
@@ -88,9 +86,8 @@ public void dispatchKernel(KernelCallGraph kernelCallGraph, NDRange ndRange, Obj
     }
 
     public String createCode(KernelCallGraph kernelCallGraph, PTXCodeBuilder builder, Object[] args) {
-        String out = "";
-        Optional<CoreOp.FuncOp> o = Optional.ofNullable(kernelCallGraph.entrypoint.funcOpWrapper().op());
-        FuncOpWrapper f = new FuncOpWrapper(o.orElseThrow());
+        StringBuilder out = new StringBuilder();
+        FuncOpWrapper f = new FuncOpWrapper(kernelCallGraph.entrypoint.funcOpWrapper().op());
         FuncOpWrapper lowered = f.lower();
         HashMap<String, Object> argsMap = new HashMap<>();
         for (int i = 0; i < args.length; i++) {
@@ -102,25 +99,20 @@ public String createCode(KernelCallGraph kernelCallGraph, PTXCodeBuilder builder
 
         // printing out ptx header (device info)
         builder.ptxHeader(major, minor, target, addressSize);
-        out += builder.getTextAndReset();
+        out.append(builder.getTextAndReset());
 
         for (KernelCallGraph.KernelReachableResolvedMethodCall k : kernelCallGraph.kernelReachableResolvedStream().toList()) {
-            Optional<CoreOp.FuncOp> optional = Optional.ofNullable(k.funcOpWrapper().op());
-            FuncOpWrapper calledFunc = new FuncOpWrapper(optional.orElseThrow());
+            FuncOpWrapper calledFunc = new FuncOpWrapper(k.funcOpWrapper().op());
             FuncOpWrapper loweredFunc = calledFunc.lower();
-//            System.out.println("------------func------------");
-//            System.out.println(loweredFunc.ssa().toText());
             if (useSchema) loweredFunc = transformPtrs(loweredFunc, argsMap);
-            out += createFunction(new PTXCodeBuilder(addressSize).nl().nl(), loweredFunc, loweredFunc.ssa(), out, false);
+            out.append(createFunction(new PTXCodeBuilder(addressSize).nl().nl(), loweredFunc, false));
         }
 
         if (useSchema) lowered = transformPtrs(lowered, argsMap);
-        FuncOpWrapper ssa = lowered.ssa();
-//        System.out.println(lowered.toText());
-//        System.out.println(ssa.toText());
-        out += createFunction(builder.nl().nl(), lowered, ssa, out, true);
 
-        return out;
+        out.append(createFunction(builder.nl().nl(), lowered, true));
+
+        return out.toString();
     }
 
     public FuncOpWrapper transformPtrs(FuncOpWrapper func, HashMap<String, Object> argsMap) {
@@ -148,8 +140,9 @@ public FuncOpWrapper transformPtrs(FuncOpWrapper func, HashMap<String, Object> a
         }));
     }
 
-    public String createFunction(PTXCodeBuilder builder, FuncOpWrapper lowered, FuncOpWrapper ssa, String out, boolean entry) {
-        String body = "";
+    public String createFunction(PTXCodeBuilder builder, FuncOpWrapper lowered, boolean entry) {
+        FuncOpWrapper ssa = lowered.ssa();
+        String out, body;
 
         // building fn info (name, params)
         builder.functionHeader(lowered.functionName(), entry, lowered.op().body().yieldType());