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public BuildStore ( |
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| dest | ||
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public void CreateArgAllocas(Function function, IRBuilder builder)
{
for(int i = 0; i < function.ArgCount; ++i)
{
Value alloca = builder.BuildEntryBlockAlloca(function, TypeRef.CreateDouble(), this.Args[i]);
builder.BuildStore(function.GetParameter((uint)i), alloca);
CodeGenManager.NamedValues[this.Args[i]] = alloca;
}
}
public override Value CodeGen(IRBuilder builder)
{
// Output this as:
// var = alloca double
// ...
// start = startexpr
// store start -> var
// goto loop
// loop:
// ...
// bodyexpr
// ...
// loopend:
// step = stepexpr
// endcond = endexpr
//
// curvar = load var
// nextvar = curvar + step
// store nextvar -> var
// br endcond, loop, endloop
// outloop:
BasicBlock startBlock = builder.GetInsertPoint();
Function func = startBlock.GetParent();
Value alloca = builder.BuildEntryBlockAlloca(func, TypeRef.CreateDouble(), this.VarName);
Value startV = this.Start.CodeGen(builder);
if(startV.IsNull) return startV;
builder.BuildStore(startV, alloca);
BasicBlock loopBB = func.AppendBasicBlock("loop");
builder.BuildBr(loopBB);
builder.SetInsertPoint(loopBB);
/* Within the loop, the variable is defined equal to the PHI node. If it
* shadows an existing variable, we have to restore it, so save it
* now. */
Value oldVal = Value.Null;
CodeGenManager.NamedValues.TryGetValue(this.VarName, out oldVal);
CodeGenManager.NamedValues[this.VarName] = alloca;
/* Emit the body of the loop. This, like any other expr, can change the
* current BB. Note that we ignore the value computed by the body, but
* don't allow an error */
Body.CodeGen(builder);
// Emit the step value;
Value stepV = Value.Null;
if(this.Step != null)
stepV = this.Step.CodeGen(builder);
else
stepV = Value.CreateConstDouble(1);
// Compute the end condition
Value endCond = this.End.CodeGen(builder);
endCond = builder.BuildFCmp(endCond, LLVMRealPredicate.RealONE, Value.CreateConstDouble(0), "loopcond");
Value curvar = builder.BuildLoad(alloca, VarName);
Value nextVar = builder.BuildFAdd(curvar, stepV, "nextvar");
builder.BuildStore(nextVar, alloca);
BasicBlock loopEndBB = builder.GetInsertPoint();
BasicBlock afterBB = func.AppendBasicBlock("afterloop");
builder.BuildCondBr(endCond, loopBB, afterBB);
builder.SetInsertPoint(afterBB);
if(!oldVal.IsNull)
CodeGenManager.NamedValues[this.VarName] = oldVal;
else
CodeGenManager.NamedValues.Remove(this.VarName);
return Value.CreateConstDouble(0);
}
