Adding a new instruction

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1

Hello Ammar,

Can you share the patch of changes in LLVM you have done already?

Regards,
Vladimir

2

Hey Vladmir,

Here’s what and where i added :

1- **llvm/include/llvm/IR/**Instruction.def :
Line 136 : HANDLE_BINARY_INST(23, increment , BinaryOperator) also changed all numbers accordingly

2- **llvm/include/llvm/IR/**Instructions.h:
Line 699:
enum BinOp {
/// *p = v
Xchg,
/// *p = old + v
Add,
/// *p = old + 1
increment,

3-**llvm/include/llvm/IR/InstVisitor.h**: NO Change, since binary operator visit is already defined

4 - llvm/lib/AsmParser/LLLexer.cpp:
Line 717 : INSTKEYWORD(add, Add); INSTKEYWORD(increment, increment); INSTKEYWORD(fadd, FAdd);

5 - llvm/lib/AsmParser/LLParser.cpp:
Line 2865 : case lltok::kw_increment:
Line 2887 : if (Opc == Instruction::Add || Opc == Instruction::increment || Opc == Instruction::Sub ||
Line 2918 : case Instruction::myAdd:
Line 4737 : case lltok::kw_increment:
Line 5942 : case lltok::kw_increment: Operation = AtomicRMWInst::increment; break;

6 - llvm/lib/Bitcode/Reader/BitcodeReader.cpp:
**Line 748 :**case bitc::BINOP_increment: return IsFP ? -1 : Instruction::increment;
Line 782 : case bitc::RMW_increment: return AtomicRMWInst::increment;
Line 2720 : Opc == Instruction::increment||
Line 4113 : Opc == Instruction::increment||

7 - llvm/lib/Bitcode/Writer/BitcodeWriter.cpp:
Line 91 : case Instruction::increment:return bitc::BINOP_increment;
Line 116 : case AtomicRMWInst::increment: return bitc::RMW_increment;

8 - llvm/lib/IR/Instruction.cpp:
Line 211 : case increment: return “increment”;
Line 495 : Opcode == Add || Opcode == increment || Opcode == Mul;
Line 522 : case increment:

9 - llvm/lib/IR/Instructions.cpp:

Line 1939 : case increment:

I’ve made these changes following the official document here : http://llvm.org/docs/ExtendingLLVM.html

Please let me know if i’m doing something wrong or anything else needs to be changed.

ThankYou!

3

So i fixed this error, i had to add LLVMincrement in core.h as a BINOP and a couple more fixes after this fix, however, after a successful make, LLVM still does not recognize my increment instruction and i get the error expected instruction opcode when i run with lli.

Please guide if anyone has added any instruction successfully to LLVM, does not necessarily have to be a binary op,i’ll pick up from wherever we are, I can not find anything at all except the official link which doesn’t seem very helpful! :frowning: