Mercurial > pub > dyncall > dyncall
view doc/manual/callconvs/callconv_sparc.tex @ 182:2f6e0dd03bed
- excluding Dragonfly also from .note.GNU-stack marking as interpreted wrongly
author | cslag |
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date | Sat, 11 Feb 2017 01:17:02 +0100 |
parents | 164cf1663b7c |
children | e210193f6cf1 |
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%////////////////////////////////////////////////////////////////////////////// % % Copyright (c) 2012-2016 Daniel Adler <dadler@uni-goettingen.de>, % Tassilo Philipp <tphilipp@potion-studios.com> % % Permission to use, copy, modify, and distribute this software for any % purpose with or without fee is hereby granted, provided that the above % copyright notice and this permission notice appear in all copies. % % THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES % WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF % MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR % ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES % WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN % ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF % OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. % %////////////////////////////////////////////////////////////////////////////// \subsection{SPARC Calling Convention} \paragraph{Overview} The SPARC family of processors is based on the SPARC instruction set architecture, which comes in basically tree revisions, V7, V8 and V9. The former two are 32-bit whereas the latter refers to the 64-bit SPARC architecture (see next chapter). SPARC is big endian.\\ \paragraph{\product{dyncall} support} \product{dyncall} fully supports the SPARC 32-bit instruction set (V7 and V8), \product{dyncallback} support is missing, though. \subsubsection{SPARC (32-bit) Calling Convention} \paragraph{Register usage} \begin{itemize} \item 32 32-bit integer/pointer registers \item 32 floating point registers (usable as 8 quad precision, 16 double precision or 32 single precision registers) \item 32 registers are accessible at a time (8 are global ones (g*), whereas the rest forms a register window with 8 input (i*), 8 output (o*) and 8 local (l*) ones) \item calling a function shifts the register window, the old output registers become the new input registers (old local and input ones are not accessible anymore) \end{itemize} \begin{table}[h] \begin{tabular*}{0.95\textwidth}{lll} Name & Alias & Brief description\\ \hline {\bf \%g0} & & Read-only, hardwired to 0 \\ {\bf \%g1-\%g7} & & Global \\ {\bf \%o0 and \%i0} & & Output and input argument 0, return value \\ {\bf \%o1-\%o5 and \%i1-\%i5} & & Output and input argument registers \\ {\bf \%o6 and \%i6} & & Stack and frame pointer \\ {\bf \%o7 and \%i7} & & Return address (caller writes to o7, callee uses i7) \\ \end{tabular*} \caption{Register usage on sparc calling convention} \end{table} \paragraph{Parameter passing} \begin{itemize} \item stack grows down \item stack parameter order: right-to-left \item caller cleans up the stack \item stack always aligned to 8 bytes \item first 6 integers and floats are passed independently in registers using \%o0-\%o5 \item for every other argument the stack is used \item all arguments <= 32 bit are passed as 32 bit values \item 64 bit arguments are passed like two consecutive <= 32 bit values \item minimum stack size is 64 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 \item if needed, register spill area is adjacent to parameters \item results are expected by caller to be returned in \%o0\%o1 (after reg window restore, meaning callee writes to \%i0\%i1) for integers, \%f0/\%f1 for floats, and for structs/unions a pointer to them is used as a hidden stack parameter (see below) \end{itemize} \paragraph{Stack layout} Stack directly after function prolog:\\ \begin{figure}[h] \begin{tabular}{5|3|1 1} \hhline{~-~~} & \vdots & & \\ \hhline{~=~~} local data & \hspace{4cm} & & \mrrbrace{10}{caller's frame} \\ \hhline{~-~~} padding & & & \\ \hhline{~-~~} \mrlbrace{7}{parameter area} & argument x & \mrrbrace{3}{stack parameters} & \\ & \ldots & & \\ & argument 6 & & \\ & input argument 5 spill & \mrrbrace{3}{spill area} & \\ & \ldots & & \\ & input argument 0 spill & & \\ & struct/union return pointer & & \\ \hhline{~-~~} register save area (\%i* and \%l*) & & & \\ \hhline{~=~~} local data and padding & & & \mrrbrace{3}{current frame} \\ \hhline{~-~~} parameter area & & & \\ \hhline{~-~~} & \vdots & & \\ \hhline{~-~~} \end{tabular} \\ \\ \\ \caption{Stack layout on sparc calling convention} \end{figure}