Mercurial > pub > dyncall > dyncall
comparison doc/manual/callconvs/callconv_sparc64.tex @ 475:5be9f5ccdd35
- doc: ppc64 clarifications
| author | Tassilo Philipp |
|---|---|
| date | Sat, 19 Feb 2022 19:27:22 +0100 |
| parents | c9e19249ecd3 |
| children | 6c72cb768099 |
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| 474:c9e19249ecd3 | 475:5be9f5ccdd35 |
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| 71 \item single precision floating point args are passed in odd \%f* registers, and are "right aligned" in their 8-byte space on the stack | 71 \item single precision floating point args are passed in odd \%f* registers, and are "right aligned" in their 8-byte space on the stack |
| 72 \item for every argument passed, corresponding \%o*, \%f* register or stack space is skipped (e.g. passing a double as 3rd call argument, \%d4 is used and \%o2 is skipped) | 72 \item for every argument passed, corresponding \%o*, \%f* register or stack space is skipped (e.g. passing a double as 3rd call argument, \%d4 is used and \%o2 is skipped) |
| 73 \item all arguments \textless=\ 64 bit are passed as 64 bit values | 73 \item all arguments \textless=\ 64 bit are passed as 64 bit values |
| 74 \item minimum stack size is 128 bytes, b/c stack pointer must always point at enough space to store all \%i* and \%l* registers, used when running out of register windows | 74 \item minimum stack size is 128 bytes, b/c stack pointer must always point at enough space to store all \%i* and \%l* registers, used when running out of register windows |
| 75 \item if needed, register spill area (both, integer and float arguments are spilled in order) is adjacent to parameters | 75 \item if needed, register spill area (both, integer and float arguments are spilled in order) is adjacent to parameters |
| 76 \item aggregates (struct, union) \textless=\ 16 bytes are passed field-by-field, {\bf however} evaluated as a sequence of 8-byte parameter slots | 76 \item structs with only one field are passed as if the param would be the field itself |
| 77 \item structs \textless=\ 16 bytes (which have more than one field) are passed field-by-field, {\bf however} evaluated as a sequence of 8-byte parameter slots | |
| 77 \begin{itemize} | 78 \begin{itemize} |
| 79 \item note that due to aggregate alignment rules, any floating point value is either the entire slot (for double precision) or exactly one half | |
| 78 \item fields are left justified in register or stack slots | 80 \item fields are left justified in register or stack slots |
| 79 \item integers in a slot are passed as such (either via \%o* registers or the stack) | 81 \item integers in a slot are passed as such (either via \%o* registers or the stack) |
| 80 \item single precision floats (using half of the slot) use even numbered \%f* registers when they occupy the left half, odd numbered ones otherwise (no register skipping logic applied within a slot) | 82 \item single precision floats (using half of the slot) use even numbered \%f* registers when they occupy the left half, odd numbered ones otherwise (no register skipping logic applied within a slot) |
| 81 \item splitting aggregates between registers and stack is allowed | 83 \item splitting struct fields between registers and stack is allowed |
| 82 \end{itemize} | 84 \end{itemize} |
| 85 \item unions \textless=\ 16 bytes passed by-value are passed like integers in left-justified 8-byte slots (either via \%o* registers or the stack) | |
| 83 \item aggregates (struct, union) and types \textgreater\ 16 bytes are passed indirectly, as a pointer to a correctly aligned copy of the data (that copy can be avoided under certain conditions) | 86 \item aggregates (struct, union) and types \textgreater\ 16 bytes are passed indirectly, as a pointer to a correctly aligned copy of the data (that copy can be avoided under certain conditions) |
| 84 % from spec: | 87 % from spec: |
| 85 %Structure or union types up to eight bytes in size are assigned to one parameter array word, and align to eight-byte | 88 %Structure or union types up to eight bytes in size are assigned to one parameter array word, and align to eight-byte |
| 86 %boundaries. | 89 %boundaries. |
| 87 %Structure or union types larger than eight bytes, and up to sixteen bytes in size are assigned to two consecutive | 90 %Structure or union types larger than eight bytes, and up to sixteen bytes in size are assigned to two consecutive |