public StrengthReduction(SsaState ssa, LinearInductionVariable liv, LinearInductionVariableContext ctx)
{
this.ssa = ssa;
this.liv = liv;
this.ctx = ctx;
incrUses = new List<IncrementedUse>();
}
public static LinearInductionVariable Merge(LinearInductionVariable liv1, LinearInductionVariable liv2)
{
if (liv1.Delta == null || liv2.Delta == null)
return null;
int delta1 = Convert.ToInt32(liv1.Delta.ToInt32());
int delta2 = Convert.ToInt32(liv2.Delta.ToInt32());
if (delta1 == 1)
return new LinearInductionVariable(null, liv1.Delta, null, liv1.IsSigned);
else if (delta2 == 1)
return new LinearInductionVariable(null, liv2.Delta, null, liv2.IsSigned);
else
{
int delta = Gcd(delta1, delta2);
if (delta == 1)
return null;
else
return new LinearInductionVariable(null, Constant.Create(liv1.Delta.DataType, delta),
null, liv1.IsSigned || liv2.IsSigned);
}
}
public void DtbInductionVariables()
{
Identifier i = new Identifier("i", PrimitiveType.Word32, null);
MemoryAccess load = new MemoryAccess(MemoryIdentifier.GlobalMemory, i, PrimitiveType.Int32);
Identifier i2 = new Identifier("i2", PrimitiveType.Word32, null);
MemoryAccess ld2 = new MemoryAccess(MemoryIdentifier.GlobalMemory, i2, PrimitiveType.Int32);
LinearInductionVariable iv = new LinearInductionVariable(
Constant.Word32(0),
Constant.Word32(1),
Constant.Word32(10),
false);
LinearInductionVariable iv2 = new LinearInductionVariable(
Constant.Word32(0x0010000),
Constant.Word32(4),
Constant.Word32(0x0010040),
false);
prog.InductionVariables.Add(i, iv);
prog.InductionVariables.Add(i2, iv2);
prog.Platform = new DefaultPlatform(null, arch);
TraitCollector trco = new TraitCollector(factory, store, dtb, prog);
prog.Globals.Accept(eqb);
load.Accept(eqb);
ld2.Accept(eqb);
prog.Globals.Accept(trco);
load.Accept(trco);
ld2.Accept(trco);
dtb.BuildEquivalenceClassDataTypes();
Verify("Typing/DtbInductionVariables.txt");
}
/// <summary>
/// Handle an expression of type 'id + offset', where id is a LinearInductionVariable.
/// </summary>
/// <param name="id"></param>
/// <param name="iv"></param>
/// <param name="offset"></param>
public void VisitInductionVariable(Identifier id, LinearInductionVariable iv, Constant cOffset)
{
int delta = iv.Delta.ToInt32();
int offset = StructureField.ToOffset(cOffset);
var tvBase = (basePointer != null) ? basePointer : prog.Globals;
var stride = Math.Abs(delta);
int init;
if (delta < 0)
{
// induction variable is decremented, so the actual array begins at ivFinal - delta.
if (iv.Final != null)
{
init = iv.Final.ToInt32() - delta;
if (iv.IsSigned)
{
handler.MemAccessArrayTrait(null, tvBase, cOffset.DataType.Size, init + offset, stride, iv.IterationCount, eField);
}
else
{
handler.MemAccessArrayTrait(null, tvBase, id.DataType.Size, init + offset, stride, iv.IterationCount, eField);
}
}
}
else
{
if (iv.Initial != null)
{
init = iv.Initial.ToInt32();
if (iv.IsSigned)
{
handler.MemAccessArrayTrait(null, tvBase, cOffset.DataType.Size, init + offset, stride, iv.IterationCount, eField);
}
else
{
handler.MemAccessArrayTrait(null, tvBase, id.DataType.Size, init + offset, stride, iv.IterationCount, eField);
}
}
}
if (iv.IsSigned)
{
if (cOffset != null)
{
handler.MemSizeTrait(basePointer, cOffset, Math.Abs(delta));
EmitAccessTrait(basePointer, cOffset, cOffset.DataType.Size, 0);
}
}
else
{
handler.MemSizeTrait(basePointer, id, Math.Abs(delta));
EmitAccessTrait(basePointer, id, id.DataType.Size, offset);
}
}
public void InCommensurate()
{
LinearInductionVariable liv1 = new LinearInductionVariable(null, Constant.Word32(3), null, false);
LinearInductionVariable liv2 = new LinearInductionVariable(null, Constant.Word32(8), null, false);
LinearInductionVariable liv =
LinearInductionVariable.Merge(liv1, liv2);
Assert.IsNull(liv);
}
public void Commensurate2()
{
LinearInductionVariable liv1 = new LinearInductionVariable(null, Constant.Word32(2), null, false);
LinearInductionVariable liv2 = new LinearInductionVariable(null, Constant.Word32(8), null, false);
LinearInductionVariable liv =
LinearInductionVariable.Merge(liv1, liv2);
Assert.IsNotNull(liv);
Assert.AreEqual(2, liv.Delta.ToInt32());
}
public void TrcoInductionVariable()
{
Identifier i = new Identifier("i", PrimitiveType.Word32, null);
MemoryAccess load = new MemoryAccess(MemoryIdentifier.GlobalMemory, i, PrimitiveType.Int32);
Identifier i2 = new Identifier("i2", PrimitiveType.Word32, null);
MemoryAccess ld2 = new MemoryAccess(MemoryIdentifier.GlobalMemory, i2, PrimitiveType.Int32);
LinearInductionVariable iv = new LinearInductionVariable(
Constant.Word32(0),
Constant.Word32(1),
Constant.Word32(10),
false);
LinearInductionVariable iv2 = new LinearInductionVariable(
Constant.Word32(0x0010000),
Constant.Word32(4),
Constant.Word32(0x0010040),
false);
Program prog = CreateProgram();
prog.InductionVariables.Add(i, iv);
prog.InductionVariables.Add(i2, iv2);
coll = CreateCollector(prog);
prog.Globals.Accept(eqb);
load.Accept(eqb);
ld2.Accept(eqb);
prog.Globals.Accept(coll);
load.Accept(coll);
ld2.Accept(coll);
Verify(null, "Typing/TrcoInductionVariable.txt");
}
