diff options
| -rw-r--r-- | utils/TableGen/AsmWriterEmitter.cpp | 57 |
1 files changed, 46 insertions, 11 deletions
diff --git a/utils/TableGen/AsmWriterEmitter.cpp b/utils/TableGen/AsmWriterEmitter.cpp index 57979b3e6d..56b2ef82b6 100644 --- a/utils/TableGen/AsmWriterEmitter.cpp +++ b/utils/TableGen/AsmWriterEmitter.cpp @@ -313,7 +313,9 @@ void AsmWriterEmitter::EmitPrintInstruction(raw_ostream &O) { /// OpcodeInfo - This encodes the index of the string to use for the first /// chunk of the output as well as indices used for operand printing. - std::vector<unsigned> OpcodeInfo; + /// To reduce the number of unhandled cases, we expand the size from 32-bit + /// to 32+16 = 48-bit. + std::vector<std::pair<unsigned, uint16_t> > OpcodeInfo; // Add all strings to the string table upfront so it can generate an optimized // representation. @@ -354,7 +356,7 @@ void AsmWriterEmitter::EmitPrintInstruction(raw_ostream &O) { } // Bias offset by one since we want 0 as a sentinel. - OpcodeInfo.push_back(Idx+1); + OpcodeInfo.push_back(std::make_pair(Idx+1, 0)); } // Figure out how many bits we used for the string index. @@ -362,7 +364,7 @@ void AsmWriterEmitter::EmitPrintInstruction(raw_ostream &O) { // To reduce code size, we compactify common instructions into a few bits // in the opcode-indexed table. - unsigned BitsLeft = 32-AsmStrBits; + unsigned BitsLeft = 32+16-AsmStrBits; std::vector<std::vector<std::string> > TableDrivenOperandPrinters; @@ -380,6 +382,13 @@ void AsmWriterEmitter::EmitPrintInstruction(raw_ostream &O) { // ceil(log2(numentries)). unsigned NumBits = Log2_32_Ceil(UniqueOperandCommands.size()); + // Check whether these Bits will fit in the first 32 bits. + if (BitsLeft > 16 && NumBits > BitsLeft - 16) + // We don't have enough bits in the first 32 bits, and we skip the + // left-over bits. + BitsLeft = 16; + bool UseSecond = (BitsLeft <= 16); + // If we don't have enough bits for this operand, don't include it. if (NumBits > BitsLeft) { DEBUG(errs() << "Not enough bits to densely encode " << NumBits @@ -390,8 +399,13 @@ void AsmWriterEmitter::EmitPrintInstruction(raw_ostream &O) { // Otherwise, we can include this in the initial lookup table. Add it in. BitsLeft -= NumBits; for (unsigned i = 0, e = InstIdxs.size(); i != e; ++i) - if (InstIdxs[i] != ~0U) - OpcodeInfo[i] |= InstIdxs[i] << (BitsLeft+AsmStrBits); + // Update the first 32 bits or the second 16 bits. + if (InstIdxs[i] != ~0U) { + if (UseSecond) + OpcodeInfo[i].second |= InstIdxs[i] << BitsLeft; + else + OpcodeInfo[i].first |= InstIdxs[i] << (BitsLeft-16+AsmStrBits); + } // Remove the info about this operand. for (unsigned i = 0, e = NumberedInstructions.size(); i != e; ++i) { @@ -413,13 +427,25 @@ void AsmWriterEmitter::EmitPrintInstruction(raw_ostream &O) { O<<" static const unsigned OpInfo[] = {\n"; for (unsigned i = 0, e = NumberedInstructions.size(); i != e; ++i) { - O << " " << OpcodeInfo[i] << "U,\t// " + O << " " << OpcodeInfo[i].first << "U,\t// " << NumberedInstructions[i]->TheDef->getName() << "\n"; } // Add a dummy entry so the array init doesn't end with a comma. O << " 0U\n"; O << " };\n\n"; + if (BitsLeft < 16) { + // Add a second OpInfo table only when it is necessary. + O<<" static const short OpInfo2[] = {\n"; + for (unsigned i = 0, e = NumberedInstructions.size(); i != e; ++i) { + O << " " << OpcodeInfo[i].second << "U,\t// " + << NumberedInstructions[i]->TheDef->getName() << "\n"; + } + // Add a dummy entry so the array init doesn't end with a comma. + O << " 0U\n"; + O << " };\n\n"; + } + // Emit the string itself. O << " const char AsmStrs[] = {\n"; StringTable.emit(O, printChar); @@ -428,12 +454,14 @@ void AsmWriterEmitter::EmitPrintInstruction(raw_ostream &O) { O << " O << \"\\t\";\n\n"; O << " // Emit the opcode for the instruction.\n" - << " unsigned Bits = OpInfo[MI->getOpcode()];\n" - << " assert(Bits != 0 && \"Cannot print this instruction.\");\n" + << " unsigned Bits = OpInfo[MI->getOpcode()];\n"; + if (BitsLeft < 16) + O << " unsigned short Bits2 = OpInfo2[MI->getOpcode()];\n"; + O << " assert(Bits != 0 && \"Cannot print this instruction.\");\n" << " O << AsmStrs+(Bits & " << (1 << AsmStrBits)-1 << ")-1;\n\n"; // Output the table driven operand information. - BitsLeft = 32-AsmStrBits; + BitsLeft = 32+16-AsmStrBits; for (unsigned i = 0, e = TableDrivenOperandPrinters.size(); i != e; ++i) { std::vector<std::string> &Commands = TableDrivenOperandPrinters[i]; @@ -442,6 +470,11 @@ void AsmWriterEmitter::EmitPrintInstruction(raw_ostream &O) { unsigned NumBits = Log2_32_Ceil(Commands.size()); assert(NumBits <= BitsLeft && "consistency error"); + // Check whether these Bits will fit in the first 32 bits. + if (BitsLeft > 16 && NumBits > BitsLeft - 16) + BitsLeft = 16; + bool UseSecond = (BitsLeft <= 16); + // Emit code to extract this field from Bits. BitsLeft -= NumBits; @@ -450,7 +483,8 @@ void AsmWriterEmitter::EmitPrintInstruction(raw_ostream &O) { if (Commands.size() == 2) { // Emit two possibilitys with if/else. - O << " if ((Bits >> " << (BitsLeft+AsmStrBits) << ") & " + O << (UseSecond ? " if ((Bits2 >> " : " if ((Bits >> ") + << (UseSecond ? BitsLeft : (BitsLeft-16+AsmStrBits)) << ") & " << ((1 << NumBits)-1) << ") {\n" << Commands[1] << " } else {\n" @@ -460,7 +494,8 @@ void AsmWriterEmitter::EmitPrintInstruction(raw_ostream &O) { // Emit a single possibility. O << Commands[0] << "\n\n"; } else { - O << " switch ((Bits >> " << (BitsLeft+AsmStrBits) << ") & " + O << (UseSecond ? " switch ((Bits2 >> " : " switch ((Bits >> ") + << (UseSecond ? BitsLeft : (BitsLeft-16+AsmStrBits)) << ") & " << ((1 << NumBits)-1) << ") {\n" << " default: // unreachable.\n"; |