fix alignment computation for nested objects #57722
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KristofferC
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The alignment of a nested object (in C layouts) is not affected by the alignment of its parent container when computing a field offset. This can be strongly counter-intuitive (as it implies adding padding where it does not seem to provide value), but is required to match the C standard. It also permits users to write custom allocators which happen to provide alignment in excess of that which codegen may assume is guaranteed, and get the behavioral characteristics they intended to specify (without resorting to computing explicit padding). Addresses #57713 (comment)
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The alignment of a nested object (in C layouts) is not affected by the alignment of its parent container when computing a field offset (as if it will be allocated at address 0). This can be strongly counter-intuitive (as it implies it should add padding where it does not seem to provide value to the user), but this is required to match the C standard. It also permits users to write custom allocators which happen to provide alignment in excess of that which codegen may assume is guaranteed, and get the behavioral characteristics they intended to specify (without resorting to computing explicit padding). Addresses #57713 (comment) (Cherry-picked from c9008ff, with typo fix to typed_loaded memcpy which was already deleted from master)
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The alignment of a nested object (in C layouts) is not affected by the alignment of its parent container when computing a field offset (as if it will be allocated at address 0). This can be strongly counter-intuitive (as it implies it should add padding where it does not seem to provide value to the user), but this is required to match the C standard. It also permits users to write custom allocators which happen to provide alignment in excess of that which codegen may assume is guaranteed, and get the behavioral characteristics they intended to specify (without resorting to computing explicit padding). Addresses #57713 (comment) (Cherry-picked from ec3c02a in v1.11 backports branch)
KristofferC
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The alignment of a nested object (in C layouts) is not affected by the alignment of its parent container when computing a field offset (as if it will be allocated at address 0). This can be strongly counter-intuitive (as it implies it should add padding where it does not seem to provide value to the user), but this is required to match the C standard. It also permits users to write custom allocators which happen to provide alignment in excess of that which codegen may assume is guaranteed, and get the behavioral characteristics they intended to specify (without resorting to computing explicit padding). Addresses #57713 (comment) (cherry picked from commit c9008ff)
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The alignment of a nested object (in C layouts) is not affected by the alignment of its parent container when computing a field offset (as if it will be allocated at address 0). This can be strongly counter-intuitive (as it implies it should add padding where it does not seem to provide value to the user), but this is required to match the C standard. It also permits users to write custom allocators which happen to provide alignment in excess of that which codegen may assume is guaranteed, and get the behavioral characteristics they intended to specify (without resorting to computing explicit padding). Addresses #57713 (comment) (Cherry-picked from c9008ff, with typo fix to typed_loaded memcpy which was already deleted from master)
KristofferC
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The alignment of a nested object (in C layouts) is not affected by the alignment of its parent container when computing a field offset (as if it will be allocated at address 0). This can be strongly counter-intuitive (as it implies it should add padding where it does not seem to provide value to the user), but this is required to match the C standard. It also permits users to write custom allocators which happen to provide alignment in excess of that which codegen may assume is guaranteed, and get the behavioral characteristics they intended to specify (without resorting to computing explicit padding). Addresses #57713 (comment) (Cherry-picked from ec3c02a in v1.11 backports branch)
KristofferC
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The alignment of a nested object (in C layouts) is not affected by the alignment of its parent container when computing a field offset (as if it will be allocated at address 0). This can be strongly counter-intuitive (as it implies it should add padding where it does not seem to provide value to the user), but this is required to match the C standard. It also permits users to write custom allocators which happen to provide alignment in excess of that which codegen may assume is guaranteed, and get the behavioral characteristics they intended to specify (without resorting to computing explicit padding). Addresses #57713 (comment) (Cherry-picked from ec3c02a in v1.11 backports branch)
KristofferC
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backport 1.11
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The alignment of a nested object (in C layouts) is not affected by the alignment of its parent container when computing a field offset (as if it will be allocated at address 0). This can be strongly counter-intuitive (as it implies it should add padding where it does not seem to provide value to the user), but this is required to match the C standard. It also permits users to write custom allocators which happen to provide alignment in excess of that which codegen may assume is guaranteed, and get the behavioral characteristics they intended to specify (without resorting to computing explicit padding).
Addresses #57713 (comment)