60 lines
1.6 KiB
Nim
60 lines
1.6 KiB
Nim
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import
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llvm_core, llvm_analysis, llvm_target
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proc factorial =
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discard initializeNativeTarget()
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discard initializeNativeAsmPrinter()
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let module = moduleCreateWithName("fac_module")
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var facArgs = [int32Type()]
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let facType = functionType(int32Type(), facArgs[0].addr, 1, 0)
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let fac = module.addFunction("fac", facType)
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fac.setFunctionCallConv(CCallConv)
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let n = fac.getParam(0)
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let
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entry = fac.appendBasicBlock("entry")
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ifTrue = fac.appendBasicBlock("iftrue")
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ifFalse = fac.appendBasicBlock("iffalse")
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endBB = fac.appendBasicBlock("end")
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builder = createBuilder()
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builder.positionBuilderAtEnd(entry)
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let ifCmp = builder.buildICmp(IntEQ, n, constInt(int32Type(), 0, 0), "n == 0")
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discard builder.buildCondBr(ifCmp, ifTrue, ifFalse)
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builder.positionBuilderAtEnd(ifTrue)
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let resIfTrue = constInt(int32Type(), 1, 0)
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discard builder.buildBr(endBB)
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builder.positionBuilderAtEnd(ifFalse)
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var
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nMinus = builder.buildSub(n, constInt(int32Type(), 1, 0), "n - 1")
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callFacArgs = [nMinus]
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callFac = builder.buildCall(fac, callFacArgs[0].addr, 1, "fac(n - 1)")
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resIfFalse = builder.buildMul(n, callFac, "n * fac(n - 1)")
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discard builder.buildBr(endBB)
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builder.positionBuilderAtEnd(endBB)
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var
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res = builder.buildPhi(int32Type(), "result")
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phiVals = [resIfTrue, resIfFalse]
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phiBlocks = [ifTrue, ifFalse]
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res.addIncoming(phiVals[0].addr, phiBlocks[0].addr, 2)
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discard builder.buildRet(res)
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var error: cstring
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let errorP = cast[cstringArray](error.addr)
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discard verifyModule(module, AbortProcessAction, errorP)
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disposeMessage(error)
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module.dumpModule()
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factorial()
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