public static int PackOffsets(int cbufOffset0, int cbufOffset1, TextureHandleType type)
{
return(cbufOffset0 | (cbufOffset1 << 14) | ((int)type << 28));
}
public static void RunPass(BasicBlock block, ShaderConfig config)
{
// We can turn a bindless into regular access by recognizing the pattern
// produced by the compiler for separate texture and sampler.
// We check for the following conditions:
// - The handle is a constant buffer value.
// - The handle is the result of a bitwise OR logical operation.
// - Both sources of the OR operation comes from a constant buffer.
for (LinkedListNode <INode> node = block.Operations.First; node != null; node = node.Next)
{
if (!(node.Value is TextureOperation texOp))
{
continue;
}
if ((texOp.Flags & TextureFlags.Bindless) == 0)
{
continue;
}
if (texOp.Inst == Instruction.Lod ||
texOp.Inst == Instruction.TextureSample ||
texOp.Inst == Instruction.TextureSize)
{
Operand bindlessHandle = Utils.FindLastOperation(texOp.GetSource(0), block);
bool rewriteSamplerType = texOp.Inst == Instruction.TextureSize;
if (bindlessHandle.Type == OperandType.ConstantBuffer)
{
SetHandle(config, texOp, bindlessHandle.GetCbufOffset(), bindlessHandle.GetCbufSlot(), rewriteSamplerType);
continue;
}
if (!(bindlessHandle.AsgOp is Operation handleCombineOp))
{
continue;
}
if (handleCombineOp.Inst != Instruction.BitwiseOr)
{
continue;
}
Operand src0 = Utils.FindLastOperation(handleCombineOp.GetSource(0), block);
Operand src1 = Utils.FindLastOperation(handleCombineOp.GetSource(1), block);
TextureHandleType handleType = TextureHandleType.SeparateSamplerHandle;
// Try to match masked pattern:
// - samplerHandle = samplerHandle & 0xFFF00000;
// - textureHandle = textureHandle & 0xFFFFF;
// - combinedHandle = samplerHandle | textureHandle;
// where samplerHandle and textureHandle comes from a constant buffer, and shifted pattern:
// - samplerHandle = samplerId << 20;
// - combinedHandle = samplerHandle | textureHandle;
// where samplerId and textureHandle comes from a constant buffer.
if (src0.AsgOp is Operation src0AsgOp)
{
if (src1.AsgOp is Operation src1AsgOp &&
src0AsgOp.Inst == Instruction.BitwiseAnd &&
src1AsgOp.Inst == Instruction.BitwiseAnd)
{
src0 = GetSourceForMaskedHandle(src0AsgOp, 0xFFFFF);
src1 = GetSourceForMaskedHandle(src1AsgOp, 0xFFF00000);
// The OR operation is commutative, so we can also try to swap the operands to get a match.
if (src0 == null || src1 == null)
{
src0 = GetSourceForMaskedHandle(src1AsgOp, 0xFFFFF);
src1 = GetSourceForMaskedHandle(src0AsgOp, 0xFFF00000);
}
if (src0 == null || src1 == null)
{
continue;
}
}
else if (src0AsgOp.Inst == Instruction.ShiftLeft)
{
Operand shift = src0AsgOp.GetSource(1);
if (shift.Type == OperandType.Constant && shift.Value == 20)
{
src0 = src1;
src1 = src0AsgOp.GetSource(0);
handleType = TextureHandleType.SeparateSamplerId;
}
}
}
else if (src1.AsgOp is Operation src1AsgOp && src1AsgOp.Inst == Instruction.ShiftLeft)
{
Operand shift = src1AsgOp.GetSource(1);
if (shift.Type == OperandType.Constant && shift.Value == 20)
{
src1 = src1AsgOp.GetSource(0);
handleType = TextureHandleType.SeparateSamplerId;
}
}
if (src0.Type != OperandType.ConstantBuffer || src1.Type != OperandType.ConstantBuffer)
{
continue;
}
SetHandle(
config,
texOp,
TextureHandle.PackOffsets(src0.GetCbufOffset(), src1.GetCbufOffset(), handleType),
TextureHandle.PackSlots(src0.GetCbufSlot(), src1.GetCbufSlot()),
rewriteSamplerType);
}
