Switch from rewrite patterns to conversion patterns. This allows to
perform type conversions together with other parts of the IR. For
example, this allows to convert from index to emit.size_t types.
This adds an `emitc.lvalue` type which models assignable lvlaues in the
type system. Operations modifying memory are restricted to this type
accordingly.
See also the discussion on
[discourse](https://discourse.llvm.org/t/rfc-separate-variables-from-ssa-values-in-emitc/75224/9).
The most notable changes are as follows.
- `emitc.variable` and `emitc.global` ops are restricted to return
`emitc.array` or `emitc.lvalue` types
- Taking the address of a value is restricted to operands with lvalue
type
- Conversion from lvalues into SSA values is done with the new
`emitc.load` op
- The var operand of the `emitc.assign` op is restricted to lvalue type
- The result of the `emitc.subscript` and `emitc.get_global` ops is a
lvalue type
- The operands and results of the `emitc.member` and
`emitc.member_of_ptr` ops are restricted to lvalue types
---------
Co-authored-by: Matthias Gehre <matthias.gehre@amd.com>
This PR is continuation of the [previous
one](https://github.com/llvm/llvm-project/pull/101478). As a result, the
`emitc::SwitchOp` op was developed inspired by `scf::IndexSwitchOp`.
Main points of PR:
- Added the `emitc::SwitchOp` op to the EmitC dialect + CppEmitter
- Corresponding tests were added
- Conversion from the SCF dialect to the EmitC dialect for the op
Remove the copy into fresh variables done when lowering scf.for into
emitc.for and use the variables carrying the init and iter values as
the loop's results.
To register the conversion the autogenerated function
`registerSCFToEmitC()` calls `createSCFToEmitC()`, which itself is also
autogenerated. The removed function, however, isn't used in the upstream
codebase.
Add an emitc.for op to the EmitC dialect as a lowering target for
scf.for, replacing its current direct translation to C; The translator
now handles emitc.for instead.
This patch recommits 126f0374cbc2110aa97e2141ac898014a8b9531a, reverted by
3ada774d0f65b44f21b360d222f446e533df1a34, along with the missing dependence.
Add an emitc.if op to the EmitC dialect. A new convert-scf-to-emitc
pass replaces the existing direct translation of scf.if to C; The
translator now handles emitc.if instead.
The emitc.if op doesn't return any value and its then/else regions are
terminated with a new scf.yield op. Values returned by scf.if are
lowered using emitc.variable ops, assigned to in the then/else regions
using a new emitc.assign op.
