[Feature] Improve !pto.tile_buf IR readability by eliding default fields and supporting aliases

[Zhendong404]

Problem

The current custom assembly printer for !pto.tile_buf always prints the full parameter list:

• loc
• dtype
• rows
• cols
• v_row
• v_col
• blayout
• slayout
• fractal
• pad

This makes PTO IR very hard to read in fusion-heavy regions, because the same long type string is repeated on nearly every operand/result.

The current behavior comes from the custom parser/printer in lib/PTO/IR/PTOTypeDefs.cpp:

• TileBufType::parse: currently expects the full keyed form in a fixed order
• TileBufType::print: currently always emits the full keyed form

Example

From a real IR dump in this checkout:

pto.tmax ins(%arg9, %arg10 : !pto.tile_buf<loc=vec, dtype=f32, rows=1, cols=16, v_row=1, v_col=16, blayout=row_major, slayout=none_box, fractal=512, pad=0>, !pto.tile_buf<loc=vec, dtype=f32, rows=1, cols=16, v_row=1, v_col=16, blayout=row_major, slayout=none_box, fractal=512, pad=0>) outs(%arg11 : !pto.tile_buf<loc=vec, dtype=f32, rows=1, cols=16, v_row=1, v_col=16, blayout=row_major, slayout=none_box, fractal=512, pad=0>)
pto.tsub ins(%arg9, %arg11 : !pto.tile_buf<loc=vec, dtype=f32, rows=1, cols=16, v_row=1, v_col=16, blayout=row_major, slayout=none_box, fractal=512, pad=0>, !pto.tile_buf<loc=vec, dtype=f32, rows=1, cols=16, v_row=1, v_col=16, blayout=row_major, slayout=none_box, fractal=512, pad=0>) outs(%arg12 : !pto.tile_buf<loc=vec, dtype=f32, rows=1, cols=16, v_row=1, v_col=16, blayout=row_major, slayout=none_box, fractal=512, pad=0>)

When this appears inside pto.fusion_region, block arguments, yields, and function-like signatures all become visually dominated by repeated type text rather than the actual dataflow.

Why this matters

This is mainly a readability and debugging problem:

• reviewing fusion/grouping/scheduling output is slower than necessary
• IR diffs become noisy
• region signatures and pto.yield lines become much harder to scan
• repeated default config values hide the semantically important differences

Suggested direction

I suggest keeping the current verbose syntax parseable for backward compatibility, but changing the default printer to a more compact form.

1. Elide redundant/default fields in the default printer

Possible rules:

• omit v_row / v_col when they are equal to rows / cols
• omit config fields when the config is the dialect default
  • blayout=row_major
  • slayout=none_box
  • fractal=512
  • pad=0
• compress rows + cols + dtype into a shaped form such as 1x16xf32

For example:

Current:

!pto.tile_buf<loc=vec, dtype=f32, rows=1, cols=16, v_row=1, v_col=16, blayout=row_major, slayout=none_box, fractal=512, pad=0>

Possible compact default:

!pto.tile_buf<vec, 1x16xf32>

And when valid shape / layout differ from defaults:

!pto.tile_buf<vec, 16x128xf32, valid=16x1, blayout=col_major>

2. Support type aliases for repeated tile_buf instances

For very repetitive IR, consider adding an OpAsmDialectInterface alias path so repeated identical tile types can print once and then be referenced via a short alias.

For example:

!pto.tb0 = !pto.tile_buf<vec, 1x16xf32>

Then ops can use !pto.tb0 instead of repeating the full type.

3. Keep a verbose/debug path available

If full information is still useful for debugging, we can keep either:

• the current syntax accepted by the parser
• an explicit verbose printing mode / debug flag

That way we improve default readability without losing inspectability.

Expected outcome

• shorter and more readable IR dumps
• much cleaner fusion-region and block-argument printing
• lower diff noise
• no semantic change to tile_buf
• backward-compatible parser behavior

Scope

This request is only about assembly syntax / textual readability. It does not request any change to tile semantics, layout semantics, or type invariants.