[cfe-dev] Implementing front-end of a user-directed optimization

[Michael Kruse via cfe-dev]

As by your example, #pragma xTool caller seems to apply on a scope,
not a block. Blocks themselves cannot be annotated, it wouldn't make
sense since blocks are merged/fused/moved and metadata on them would
be lost. Metadata only applies to instructions, functions have
attributes. You can also insert intrinsic instruction (e.g. "begin of
scope" and "end of scope") into the instruction stream.

Michael

Am Di., 23. Juni 2020 um 14:13 Uhr schrieb Probir Roy <proy.cse at gmail.com>:
>
> I was able to add attributes to AST. However, I am currently stuck in
> code generation. I am trying to add meta-data to the AttributedStmt
> but I am not sure how to do it.
>
> For now, I have generated the following AttributedStmt in AST:
>
> |   |-AttributedStmt 0x5630129efcc8 <<invalid sloc>, line:12:16>
> |   | |-MyCustomAttr 0x5630129efc90 <line:11:9, col:38> Implicit Call foo foo2
> |   | `-BinaryOperator 0x5630129efc70 <line:12:2, col:16> 'int' '='
> |   |   |-DeclRefExpr 0x5630129efb78 <col:2> 'int' lvalue Var
> 0x5630129ef9d8 'c2' 'int'
> |   |   `-CallExpr 0x5630129efc10 <col:7, col:16> 'int'
> |   |     |-ImplicitCastExpr 0x5630129efbf8 <col:7> 'int (*)(int,
> int)' <FunctionToPointerDecay>
> |   |     | `-DeclRefExpr 0x5630129efb98 <col:7> 'int (int, int)'
> Function 0x5630129ef5a0 'foo2' 'int (int, int)'
> |   |     |-ImplicitCastExpr 0x5630129efc40 <col:12> 'int' <LValueToRValue>
> |   |     | `-DeclRefExpr 0x5630129efbb8 <col:12> 'int' lvalue Var
> 0x5630129ef8d8 'a' 'int'
> |   |     `-ImplicitCastExpr 0x5630129efc58 <col:15> 'int' <LValueToRValue>
> |   |       `-DeclRefExpr 0x5630129efbd8 <col:15> 'int' lvalue Var
> 0x5630129ef958 'b' 'int'
>
> Now, I want to add some metadata to these enclosed attributed
> statements and generate IR. I understand that I can use setMetadata
> for adding metadata to an instruction.
> For the above case, should I create a new block with the attributed
> statements and then add meta-data to the block? How can I create a new
> block with the attributed statement?
> Can you please provide some directions/example code on how to add
> metadata to the "attributed" statements?
>
> Here is the example code and generated AST:
> https://gist.github.com/proywm/a8c47bc8b863a782d4201499f2aae2a1
>
> --
> Probir Roy