[MLIR][Doc] Remove LLVM dialect typed pointer documentation (#71246)

This commit removes all references to typed pointers. Typed pointers
have been deprecated for a while now and they will be removed in a
followup.

Related PSA:
https://discourse.llvm.org/t/psa-removal-of-typed-pointers-from-the-llvm-dialect/74502

Author: Dinistro

mlir/docs/Dialects/LLVM.md

@@ -210,9 +210,9 @@ style for types with nested angle brackets and keyword specifiers rather than
 using different bracket styles to differentiate types. Types inside the angle
 brackets may omit the `!llvm.` prefix for brevity: the parser first attempts to
 find a type (starting with `!` or a built-in type) and falls back to accepting a
-keyword. For example, `!llvm.ptr<!llvm.ptr<i32>>` and `!llvm.ptr<ptr<i32>>` are
-equivalent, with the latter being the canonical form, and denote a pointer to a
-pointer to a 32-bit integer.
+keyword. For example, `!llvm.struct<(!llvm.ptr, f32)>` and
+`!llvm.struct<(ptr, f32)>` are equivalent, with the latter being the canonical
+form, and denote a struct containing a pointer and a float.
 
 ### Built-in Type Compatibility
 
@@ -232,8 +232,8 @@ compatibility check.
 
 Each LLVM IR type corresponds to *exactly one* MLIR type, either built-in or
 LLVM dialect type. For example, because `i32` is LLVM-compatible, there is no
-`!llvm.i32` type. However, `!llvm.ptr<T>` is defined in the LLVM dialect as
-there is no corresponding built-in type.
+`!llvm.i32` type. However, `!llvm.struct<(T, ...)>` is defined in the LLVM
+dialect as there is no corresponding built-in type.
 
 ### Additional Simple Types
 
@@ -263,24 +263,19 @@ the element type, which can be either compatible built-in or LLVM dialect types.
 
 Pointer types specify an address in memory.
 
-Both opaque and type-parameterized pointer types are supported.
-[Opaque pointers](https://llvm.org/docs/OpaquePointers.html) do not indicate the
-type of the data pointed to, and are intended to simplify LLVM IR by encoding
-behavior relevant to the pointee type into operations rather than into types.
-Non-opaque pointer types carry the pointee type as a type parameter. Both kinds
-of pointers may be additionally parameterized by an address space. The address
-space is an integer, but this choice may be reconsidered if MLIR implements
-named address spaces. The syntax of pointer types is as follows:
+Pointers are [opaque](https://llvm.org/docs/OpaquePointers.html), i.e., do not
+indicate the type of the data pointed to, and are intended to simplify LLVM IR
+by encoding behavior relevant to the pointee type into operations rather than
+into types. Pointers can optionally be parametrized with an address space. The
+address space is an integer, but this choice may be reconsidered if MLIR
+implements named address spaces. The syntax of pointer types is as follows:
 
 ```
   llvm-ptr-type ::= `!llvm.ptr` (`<` integer-literal `>`)?
-                  | `!llvm.ptr<` type (`,` integer-literal)? `>`
 ```
 
-where the former case is the opaque pointer type and the latter case is the
-non-opaque pointer type; the optional group containing the integer literal
-corresponds to the memory space. All cases are represented by `LLVMPointerType`
-internally.
+where the optional group containing the integer literal corresponds to the
+address space. All cases are represented by `LLVMPointerType` internally.
 
 #### Array Types
 
@@ -346,7 +341,7 @@ syntax:
 
 Note that the sets of element types supported by built-in and LLVM dialect
 vector types are mutually exclusive, e.g., the built-in vector type does not
-accept `!llvm.ptr<i32>` and the LLVM dialect fixed-width vector type does not
+accept `!llvm.ptr` and the LLVM dialect fixed-width vector type does not
 accept `i32`.
 
 The following functions are provided to operate on any kind of the vector types
@@ -367,12 +362,11 @@ compatible with the LLVM dialect:
 
 ```mlir
 vector<42 x i32>                   // Vector of 42 32-bit integers.
-!llvm.vec<42 x ptr<i32>>           // Vector of 42 pointers to 32-bit integers.
+!llvm.vec<42 x ptr>                // Vector of 42 pointers.
 !llvm.vec<? x 4 x i32>             // Scalable vector of 32-bit integers with
                                    // size divisible by 4.
 !llvm.array<2 x vector<2 x i32>>   // Array of 2 vectors of 2 32-bit integers.
-!llvm.array<2 x vec<2 x ptr<i32>>> // Array of 2 vectors of 2 pointers to 32-bit
-                                   // integers.
+!llvm.array<2 x vec<2 x ptr>> // Array of 2 vectors of 2 pointers.
 ```
 
 ### Structure Types
@@ -421,21 +415,6 @@ type-or-ref ::= <any compatible type with optional !llvm.>
               | `!llvm.`? `struct<` string-literal `>`
 ```
 
-The body of the identified struct is printed in full unless the it is
-transitively contained in the same struct. In the latter case, only the
-identifier is printed. For example, the structure containing the pointer to
-itself is represented as `!llvm.struct<"A", (ptr<"A">)>`, and the structure `A`
-containing two pointers to the structure `B` containing a pointer to the
-structure `A` is represented as `!llvm.struct<"A", (ptr<"B", (ptr<"A">)>,
-ptr<"B", (ptr<"A">))>`. Note that the structure `B` is "unrolled" for both
-elements. _A structure with the same name but different body is a syntax error._
-**The user must ensure structure name uniqueness across all modules processed in
-a given MLIR context.** Structure names are arbitrary string literals and may
-include, e.g., spaces and keywords.
-
-Identified structs may be _opaque_. In this case, the body is unknown but the
-structure type is considered _initialized_ and is valid in the IR.
-
 #### Literal Structure Types
 
 Literal structures are uniqued according to the list of elements they contain,
@@ -460,11 +439,10 @@ elements provided.
 !llvm.struct<packed (i8, i32)>  // packed struct
 !llvm.struct<"a">               // recursive reference, only allowed within
                                 // another struct, NOT allowed at top level
-!llvm.struct<"a", ptr<struct<"a">>>  // supported example of recursive reference
 !llvm.struct<"a", ()>           // empty, named (necessary to differentiate from
                                 // recursive reference)
 !llvm.struct<"a", opaque>       // opaque, named
-!llvm.struct<"a", (i32)>        // named
+!llvm.struct<"a", (i32, ptr)>        // named
 !llvm.struct<"a", packed (i8, i32)>  // named, packed
 ```
 

mlir/docs/SPIRVToLLVMDialectConversion.md

@@ -45,7 +45,7 @@ A SPIR-V pointer also takes a Storage Class. At the moment, conversion does
 
 SPIR-V Dialect                                | LLVM Dialect
 :-------------------------------------------: | :-------------------------:
-`!spirv.ptr< <element-type>, <storage-class> >` | `!llvm.ptr<<element-type>>`
+`!spirv.ptr< <element-type>, <storage-class> >` | `!llvm.ptr`
 
 ### Array types
 
@@ -443,7 +443,7 @@ order to go through the pointer.
 %i   = ...
 %var = ...
 %0   = llvm.mlir.constant(0 : i32) : i32
-%el  = llvm.getelementptr %var[%0, %i, %i] : (!llvm.ptr<struct<packed (f32, array<4 x f32>)>>, i32, i32, i32)
+%el  = llvm.getelementptr %var[%0, %i, %i] : (!llvm.ptr, i32, i32, i32), !llvm.struct<packed (f32, array<4 x f32>)>
 ```
 
 #### `spirv.Load` and `spirv.Store`
@@ -453,16 +453,16 @@ These ops are converted to their LLVM counterparts: `llvm.load` and
 following cases, based on the value of the attribute:
 
 *   **Aligned**: alignment is passed on to LLVM op builder, for example: `mlir
-    // llvm.store %ptr, %val {alignment = 4 : i64} : !llvm.ptr<f32> spirv.Store
+    // llvm.store %ptr, %val {alignment = 4 : i64} : !llvm.ptr spirv.Store
     "Function" %ptr, %val ["Aligned", 4] : f32`
 *   **None**: same case as if there is no memory access attribute.
 
 *   **Nontemporal**: set `nontemporal` flag, for example: `mlir // %res =
-    llvm.load %ptr {nontemporal} : !llvm.ptr<f32> %res = spirv.Load "Function"
+    llvm.load %ptr {nontemporal} : !llvm.ptr %res = spirv.Load "Function"
     %ptr ["Nontemporal"] : f32`
 
 *   **Volatile**: mark the op as `volatile`, for example: `mlir // %res =
-    llvm.load volatile %ptr : !llvm.ptr<f32> %res = spirv.Load "Function" %ptr
+    llvm.load volatile %ptr : !llvm.ptr f32> %res = spirv.Load "Function" %ptr
     ["Volatile"] : f32` Otherwise the conversion fails as other cases
     (`MakePointerAvailable`, `MakePointerVisible`, `NonPrivatePointer`) are not
     supported yet.
@@ -491,7 +491,7 @@ spirv.module Logical GLSL450 {
 module {
   llvm.mlir.global private @struct() : !llvm.struct<packed (f32, [10 x f32])>
   llvm.func @func() {
-    %0 = llvm.mlir.addressof @struct : !llvm.ptr<struct<packed (f32, [10 x f32])>>
+    %0 = llvm.mlir.addressof @struct : !llvm.ptr
     llvm.return
   }
 }
@@ -535,13 +535,13 @@ Also, at the moment initialization is only possible via `spirv.Constant`.
 ```mlir
 // Conversion of VariableOp without initialization
                                                                %size = llvm.mlir.constant(1 : i32) : i32
-%res = spirv.Variable : !spirv.ptr<vector<3xf32>, Function>   =>   %res  = llvm.alloca  %size x vector<3xf32> : (i32) -> !llvm.ptr<vec<3 x f32>>
+%res = spirv.Variable : !spirv.ptr<vector<3xf32>, Function>   =>   %res  = llvm.alloca  %size x vector<3xf32> : (i32) -> !llvm.ptr
 
 // Conversion of VariableOp with initialization
                                                                %c    = llvm.mlir.constant(0 : i64) : i64
 %c   = spirv.Constant 0 : i64                                    %size = llvm.mlir.constant(1 : i32) : i32
-%res = spirv.Variable init(%c) : !spirv.ptr<i64, Function>    =>   %res  = llvm.alloca %[[SIZE]] x i64 : (i32) -> !llvm.ptr<i64>
-                                                               llvm.store %c, %res : !llvm.ptr<i64>
+%res = spirv.Variable init(%c) : !spirv.ptr<i64, Function>    =>   %res  = llvm.alloca %[[SIZE]] x i64 : (i32) -> !llvm.ptr
+                                                               llvm.store %c, %res : i64, !llvm.ptr
 ```
 
 Note that simple conversion to `alloca` may not be sufficient if the code has