/**
* Create code for the work function of a built-in filter.
*
* @param filter The filter that the work function is being built for
* @param selfID A unique id assigned in FlatIRToC
* @param p A printer to output the generated code
*/
static void predefinedFilterWork(SIRPredefinedFilter filter, int selfID, CodegenPrintWriter p) {
Tape inputTape = RegisterStreams.getFilterInStream(filter);
Tape outputTape = RegisterStreams.getFilterOutStream(filter);
// Caller has printed function name and an iteration parameter ____n
// Generate loop to execute body of this function ____n times,
// In loop generate specialized code for function.
p.print("void " + ClusterUtils.getWorkName(filter, selfID) + "(int ____n) {");
p.indent();
p.newLine();
p.indent();
// p.println("// predefinedFilterWork " + filter.getName());
// SIRFileReader
if (filter instanceof SIRFileReader) {
if (!(KjcOptions.mencoder || KjcOptions.blender)) {
genFileReaderWork((SIRFileReader) filter, outputTape, selfID, p);
}
// SIRFileWriter
} else if (filter instanceof SIRFileWriter) {
if (!(KjcOptions.mencoder || KjcOptions.blender)) {
genFileWriterWork((SIRFileWriter) filter, inputTape, selfID, p);
}
// SIRIdentity
} else if (filter instanceof SIRIdentity) {
assert false : "should not process SIRIdentity here";
p.println("for (; 0 < ____n; ____n--) {");
p.indent();
p.println(" " + outputTape.getPushName() + "(" + inputTape.getPopName() + "());");
p.outdent();
p.print("}"); // end of for loop.
} else if (filter instanceof SIRDummySink || filter instanceof SIRDummySource) {
// DummySource and SummySink do not appear in any of our
// application code. Are they part of the language?
// TODO: get right exception for unimplemented.
throw new Error("Unsupported predefined filter " + filter.getName());
} else {
// TODO: get right unchecked exception for unextended code...
throw new Error("Unknown predefined filter " + filter.getName());
}
p.newLine();
p.outdent(); // end of method body
p.outdent(); // end of method definition
p.print("}");
p.newLine();
p.newLine();
}
/*
* There is special case code for FileReader<bit> since individual
* bits can not be read in by any system routine that I know.
*
* With most bit streams that I (A.D.) have seen, the order is
* little-endian in words, low-to-high bit in bytes.
* This code -- matching Matt's implementation for the library
* is a bit odd: endian-ness depends on fread / fwrite -- my
* laziness, should always be little-endian -- but bits are read
* and written from high to low. So byte 0b10011111
* is read as 1, 0, 0, 1, 1, 1, 1, 1 and is written back as
* 0b10011111. This looks a little odd if a bit stream does not
* end on a byte boundary: writing stream 1,0,1,1 results in 0b10110000
*
* If we change the number of bits bufferred from 1 byte to a larger
* integer type, we will have to worry about endian-ness on disk.
* This code was designed for .BMP files, which are little-endian.
* on disk. We will also have to worry about file lengths: Unix allows
* file lengths in bytes, this will involve some extra code for not writing
* an excessive number of bytes on the last write, causing the file lengths
* to be dependent on the size of 'bits_type'.
**/
private static void genFileReaderWorkBit(
SIRFileReader filter, Tape outputTape, int selfID, CodegenPrintWriter p) {
// haven't bothered to do buffered file input on top of the
// bit input (it is possible but seems a little complicated)
System.err.println(
"PERFORMANCE WARNING: FileReader<bit> reads only 1 byte"
+ " at a time; faster to use FileReader<int>, which is buffered.");
// String theType = "" + filter.getOutputType();
// wrap in loop
p.println("for (; 0 < ____n; ____n--) {");
p.indent();
// the bit type is special since you can not just read or
// write a bit. It requires bufferring in some larger
// integer type.
String bits_to_go = bitsToGoName(filter);
String the_bits = theBitsName(filter);
p.println("static " + bits_type + " " + the_bits + " = 0;");
p.println("static int " + bits_to_go + " = 0;");
p.newline();
p.println("if (" + bits_to_go + " == 0) {");
p.indent();
p.println(
"if (fread("
+ "&"
+ the_bits
+ ", "
+ "sizeof("
+ the_bits
+ "),"
+ " "
+ "1, "
+ fpName(filter)
+ ")) {");
p.indent();
p.println(bits_to_go + " = 8 * sizeof(" + the_bits + ");");
// identical to code fragment below ///////////////////////
p.println(
outputTape.getPushName()
+ "(("
+ the_bits
+ " & (1 << (sizeof("
+ the_bits
+ ") * 8 - 1))) ? 1 : 0);");
p.println(the_bits + " <<= 1;");
p.println(bits_to_go + "--;");
// end identical to code fragment below ////////////////////
p.outdent();
p.println("}");
p.outdent();
p.println("} else {");
p.indent();
// identical to code fragment above /////////////////////////
p.println(
outputTape.getPushName()
+ "(("
+ the_bits
+ " & (1 << (sizeof("
+ the_bits
+ ") * 8 - 1))) ? 1 : 0);");
p.println(the_bits + " <<= 1;");
p.println(bits_to_go + "--;");
// end identical to code fragment above /////////////////////
p.outdent();
p.println("}");
// close loop
p.outdent();
p.print("}"); // end of for loop.
}
/*
* File reader code currently works by using fread.
*
* The File* is declared outside any function / method.
*
* This code follows the model in the library of stalling (not pushing)
* at end of file (detected by fread returning 0).
*
*/
private static void genFileReaderWork(
SIRFileReader filter, Tape outputTape, int selfID, CodegenPrintWriter p) {
if (KjcOptions.asciifileio) {
System.err.println("Error: -asciifileio not supported in cluster backend.");
System.err.println("Exiting...");
System.exit(1);
}
String theType = "" + filter.getOutputType();
// dispatch to special routine for bit type
if (theType.equals("bit")) {
genFileReaderWorkBit(filter, outputTape, selfID, p);
return;
}
// get source and destination ids of outgoing tape
Tape out = RegisterStreams.getFilterOutStream(filter);
int s = out.getSource();
int d = out.getDest();
// template code to generate, using symbolic free vars above.
StringBuilder sb = new StringBuilder();
sb.append("\n int __index;\n");
sb.append(" for (__index=0; __index < ____n; __index++) {\n");
if (KjcOptions.compressed) {
sb.append(" unsigned char __temp = 0;\n");
sb.append(" FileReader_read(__file_descr__");
sb.append(selfID);
sb.append(", &__temp, 1);\n");
sb.append(" PUSH(__temp);\n");
sb.append(" unsigned int __frame_size = __temp;\n");
sb.append(" FileReader_read(__file_descr__");
sb.append(selfID);
sb.append(", &__temp, 1);\n");
sb.append(" PUSH(__temp);\n");
sb.append(" __frame_size <<= 8;\n");
sb.append(" __frame_size += __temp;\n");
sb.append(" FileReader_read(__file_descr__");
sb.append(selfID);
sb.append(", &__temp, 1);\n");
sb.append(" PUSH(__temp);\n");
sb.append(" __frame_size <<= 8;\n");
sb.append(" __frame_size += __temp;\n");
sb.append(" FileReader_read(__file_descr__");
sb.append(selfID);
sb.append(", &__temp, 1);\n");
sb.append(" PUSH(__temp);\n");
sb.append(" __frame_size <<= 8;\n");
sb.append(" __frame_size += __temp;\n");
// the frame size includes the four bytes used to state the frame size
sb.append(" FileReader_read(__file_descr__");
sb.append(selfID);
sb.append(", (void *)(BUFFER + HEAD), __frame_size - 4);\n");
sb.append(" HEAD += __frame_size - 4;\n");
} else {
sb.append(" PUSH(FileReader_read<");
sb.append(theType);
sb.append(">(__file_descr__");
sb.append(selfID);
sb.append("));\n");
}
sb.append(" }\n");
String template = sb.toString();
/*
" #ifdef FUSED" + "\n" +
" #ifdef NOMOD" + "\n" +
" // read directly into buffer" + "\n" +
" if (fread(&(BUFFER[HEAD]), sizeof(BUFFER[HEAD]), ____n, FILEREADER)) {" + "\n" +
" HEAD+=____n;" + "\n" +
" }" + "\n" +
" #else" + "\n" +
" // wraparound buffer, might have to read in two pieces (but never" + "\n" +
" // more, since we would overwrote what we already wrote on this call)" + "\n" +
" if (HEAD+____n <= __BUF_SIZE_MASK) {" + "\n" +
" // no overflow" + "\n" +
" if (fread(&(BUFFER[HEAD]), sizeof(BUFFER[HEAD]), ____n, FILEREADER)) {" + "\n" +
" HEAD+=____n;" + "\n" +
" }" + "\n" +
" } else {" + "\n" +
" // overflow, need two pieces" + "\n" +
" int piece1 = __BUF_SIZE_MASK - HEAD;" + "\n" +
" int piece2 = ____n - piece1;" + "\n" +
" if (fread(&(BUFFER[HEAD]), sizeof(BUFFER[HEAD]), piece1, FILEREADER)) {" + "\n" +
" if (fread(&(BUFFER[0]), sizeof(BUFFER[HEAD]), piece2, FILEREADER)) {" + "\n" +
" HEAD+=____n;" + "\n" +
" HEAD&=__BUF_SIZE_MASK;" + "\n" +
" }" + "\n" +
" }" + "\n" +
" }" + "\n" +
" #endif" + "\n" +
" #else" + "\n" +
" // read as a block" + "\n" +
" TYPE __buffer[____n];" + "\n" +
" int __index;" + "\n" +
" if (fread(__buffer, sizeof(__buffer[0]), ____n, FILEREADER)) {" + "\n" +
" for (__index=0; __index < ____n; __index++) {" + "\n" +
" // should move push out of loop, but not clear if mult-push implemented yet" + "\n" +
" PUSH(__buffer[__index]);" + "\n" +
" }" + "\n" +
" }" + "\n" +
" #endif";
*/
// set values of free variables
String TYPE = theType;
String FILEREADER = fpName(filter);
String FUSED = "__FUSED_" + s + "_" + d;
String NOMOD = "__NOMOD_" + s + "_" + d;
String BUFFER = "BUFFER_" + s + "_" + d;
String HEAD = "HEAD_" + s + "_" + d;
String BUF_SIZE_MASK = "__BUF_SIZE_MASK_" + s + "_" + d;
String PUSH = outputTape.getPushName();
// replace templates with correct values
template = Utils.replaceAll(template, "TYPE", TYPE);
template = Utils.replaceAll(template, "FILEREADER", FILEREADER);
template = Utils.replaceAll(template, "FUSED", FUSED);
template = Utils.replaceAll(template, "NOMOD", NOMOD);
template = Utils.replaceAll(template, "BUFFER", BUFFER);
template = Utils.replaceAll(template, "HEAD", HEAD);
template = Utils.replaceAll(template, "BUF_SIZE_MASK", BUF_SIZE_MASK);
template = Utils.replaceAll(template, "PUSH", PUSH);
// output code
p.println(template);
}
