[CIR][CIRGen] Add CIRGen support for pointer-to-member-functions #722
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Sorry for the delay here, taking a look next week! |
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Rebased onto the latest |
| llvm::TypeSize | ||
| MethodType::getTypeSizeInBits(const mlir::DataLayout &dataLayout, | ||
| mlir::DataLayoutEntryListRef params) const { | ||
| // TODO: consider size differences under different ABIs |
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We already have a better ABI infra, you should implement what's necessary here, at least for one target.
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How should I query for ABI specific information in the data layout interface? Btw this problem also exists in ABI-related other types such as pointers and members.
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I was thinking about forwarding the question to the actual behavior this corresponds in the lower level. For example: !cir.method<!cir.func<!void (!s32i)> in !ty_22Foo22>, is this ends up being a pair of integer? I see LLVM generates:
define dso_local { i64, i64 } @make_virtual()() {
ret { i64, i64 } { i64 9, i64 0 }, !dbg !22
}
We could say that the getTypeSizeInBits here is the getTypeSizeInBits of a struct { i64, i64 };. Perhaps it's equivalent to the size of a pair of two pointer ABI size? Seems like we can compose an answer here. By the way, where does llvm::TypeSize::getFixed(128) comes from?
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This could be more subtle. The Itanium ABI actually defines the layout of a member function pointer as something like struct { fnptr_t, ptrdiff_t } where fnptr_t is the type for normal function pointers. Thus on most 64-bit platforms a member function pointer will end up being a struct { int64_t, int64_t }, and its size is 128 bits, thus the default implementation llvm::TypeSize::getFixed(128).
Three points worth mentioning here:
- Nothing in the standard stops
ptrdiff_tfrom having a different size or alignment requirement than a normal pointer. (but this is rare and I doubt if there are any implementations doing this) - On 32-bit platforms both of
fnptr_tandptrdiff_tbecomeint32_tand the member function pointer size changes as well. - In MSVC ABI a member function pointer has the same layout as a single function pointer, which is totally different from Itanium ABI.
For now we're focusing on the Itanium ABI only, so maybe let's first tackle the second point. A better type size query implementation for the member function pointers would then be the size of a struct { pointer, pointer }.
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For now we're focusing on the Itanium ABI only, so maybe let's first tackle the second point. A better type size query implementation for the member function pointers would then be the size of a
struct { pointer, pointer }.
Sounds good to me, please change it to the size of a struct { pointer, pointer } and add a missing feature assert for MSVC ABI.
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Rebased onto the latest |
| llvm::TypeSize | ||
| MethodType::getTypeSizeInBits(const mlir::DataLayout &dataLayout, | ||
| mlir::DataLayoutEntryListRef params) const { | ||
| // TODO: consider size differences under different ABIs |
There was a problem hiding this comment.
I was thinking about forwarding the question to the actual behavior this corresponds in the lower level. For example: !cir.method<!cir.func<!void (!s32i)> in !ty_22Foo22>, is this ends up being a pair of integer? I see LLVM generates:
define dso_local { i64, i64 } @make_virtual()() {
ret { i64, i64 } { i64 9, i64 0 }, !dbg !22
}
We could say that the getTypeSizeInBits here is the getTypeSizeInBits of a struct { i64, i64 };. Perhaps it's equivalent to the size of a pair of two pointer ABI size? Seems like we can compose an answer here. By the way, where does llvm::TypeSize::getFixed(128) comes from?
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Also one conflict |
This patch adds the initial CIRGen support for pointer-to-member-functions. It
contains the following new types, attributes, and operations:
- `!cir.method`, which represents the pointer-to-member-function type.
- `#cir.method`, which represents a literal pointer-to-member-function value
that points to member functions.
- `cir.get_method`, which resolves a pointer-to-member-function to a function
pointer as the callee.
See the new test at `clang/test/CIR/CIRGen/pointer-to-member-func.cpp` for how
these new CIR stuff works to support pointer-to-member-functions.
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…m#722) This PR adds the initial CIRGen support for pointer-to-member-functions. It contains the following new types, attributes, and operations: - `!cir.method`, which represents the pointer-to-member-function type. - `#cir.method`, which represents a literal pointer-to-member-function value that points to ~~non-virtual~~ member functions. - ~~`#cir.virtual_method`, which represents a literal pointer-to-member-function value that points to virtual member functions.~~ - ~~`cir.get_method_callee`~~ `cir.get_method`, which resolves a pointer-to-member-function to a function pointer as the callee. See the new test at `clang/test/CIR/CIRGen/pointer-to-member-func.cpp` for how these new CIR stuff works to support pointer-to-member-functions.
…m#722) This PR adds the initial CIRGen support for pointer-to-member-functions. It contains the following new types, attributes, and operations: - `!cir.method`, which represents the pointer-to-member-function type. - `#cir.method`, which represents a literal pointer-to-member-function value that points to ~~non-virtual~~ member functions. - ~~`#cir.virtual_method`, which represents a literal pointer-to-member-function value that points to virtual member functions.~~ - ~~`cir.get_method_callee`~~ `cir.get_method`, which resolves a pointer-to-member-function to a function pointer as the callee. See the new test at `clang/test/CIR/CIRGen/pointer-to-member-func.cpp` for how these new CIR stuff works to support pointer-to-member-functions.
…m#722) This PR adds the initial CIRGen support for pointer-to-member-functions. It contains the following new types, attributes, and operations: - `!cir.method`, which represents the pointer-to-member-function type. - `#cir.method`, which represents a literal pointer-to-member-function value that points to ~~non-virtual~~ member functions. - ~~`#cir.virtual_method`, which represents a literal pointer-to-member-function value that points to virtual member functions.~~ - ~~`cir.get_method_callee`~~ `cir.get_method`, which resolves a pointer-to-member-function to a function pointer as the callee. See the new test at `clang/test/CIR/CIRGen/pointer-to-member-func.cpp` for how these new CIR stuff works to support pointer-to-member-functions.
…m#722) This PR adds the initial CIRGen support for pointer-to-member-functions. It contains the following new types, attributes, and operations: - `!cir.method`, which represents the pointer-to-member-function type. - `#cir.method`, which represents a literal pointer-to-member-function value that points to ~~non-virtual~~ member functions. - ~~`#cir.virtual_method`, which represents a literal pointer-to-member-function value that points to virtual member functions.~~ - ~~`cir.get_method_callee`~~ `cir.get_method`, which resolves a pointer-to-member-function to a function pointer as the callee. See the new test at `clang/test/CIR/CIRGen/pointer-to-member-func.cpp` for how these new CIR stuff works to support pointer-to-member-functions.
This PR adds the initial CIRGen support for pointer-to-member-functions. It contains the following new types, attributes, and operations:
!cir.method, which represents the pointer-to-member-function type.#cir.method, which represents a literal pointer-to-member-function value that points tonon-virtualmember functions.#cir.virtual_method, which represents a literal pointer-to-member-function value that points to virtual member functions.cir.get_method_calleecir.get_method, which resolves a pointer-to-member-function to a function pointer as the callee.See the new test at
clang/test/CIR/CIRGen/pointer-to-member-func.cppfor how these new CIR stuff works to support pointer-to-member-functions.