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author | S. Solomon Darnell | 2025-03-28 21:52:21 -0500 |
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committer | S. Solomon Darnell | 2025-03-28 21:52:21 -0500 |
commit | 4a52a71956a8d46fcb7294ac71734504bb09bcc2 (patch) | |
tree | ee3dc5af3b6313e921cd920906356f5d4febc4ed /.venv/lib/python3.12/site-packages/greenlet/platform/switch_aarch64_gcc.h | |
parent | cc961e04ba734dd72309fb548a2f97d67d578813 (diff) | |
download | gn-ai-master.tar.gz |
Diffstat (limited to '.venv/lib/python3.12/site-packages/greenlet/platform/switch_aarch64_gcc.h')
-rw-r--r-- | .venv/lib/python3.12/site-packages/greenlet/platform/switch_aarch64_gcc.h | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/greenlet/platform/switch_aarch64_gcc.h b/.venv/lib/python3.12/site-packages/greenlet/platform/switch_aarch64_gcc.h new file mode 100644 index 00000000..058617c4 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/greenlet/platform/switch_aarch64_gcc.h @@ -0,0 +1,124 @@ +/* + * this is the internal transfer function. + * + * HISTORY + * 07-Sep-16 Add clang support using x register naming. Fredrik Fornwall + * 13-Apr-13 Add support for strange GCC caller-save decisions + * 08-Apr-13 File creation. Michael Matz + * + * NOTES + * + * Simply save all callee saved registers + * + */ + +#define STACK_REFPLUS 1 + +#ifdef SLP_EVAL +#define STACK_MAGIC 0 +#define REGS_TO_SAVE "x19", "x20", "x21", "x22", "x23", "x24", "x25", "x26", \ + "x27", "x28", "x30" /* aka lr */, \ + "v8", "v9", "v10", "v11", \ + "v12", "v13", "v14", "v15" + +/* + * Recall: + asm asm-qualifiers ( AssemblerTemplate + : OutputOperands + [ : InputOperands + [ : Clobbers ] ]) + + or (if asm-qualifiers contains 'goto') + + asm asm-qualifiers ( AssemblerTemplate + : OutputOperands + : InputOperands + : Clobbers + : GotoLabels) + + and OutputOperands are + + [ [asmSymbolicName] ] constraint (cvariablename) + + When a name is given, refer to it as ``%[the name]``. + When not given, ``%i`` where ``i`` is the zero-based index. + + constraints starting with ``=`` means only writing; ``+`` means + reading and writing. + + This is followed by ``r`` (must be register) or ``m`` (must be memory) + and these can be combined. + + The ``cvariablename`` is actually an lvalue expression. + + In AArch65, 31 general purpose registers. If named X0... they are + 64-bit. If named W0... they are the bottom 32 bits of the + corresponding 64 bit register. + + XZR and WZR are hardcoded to 0, and ignore writes. + + Arguments are in X0..X7. C++ uses X0 for ``this``. X0 holds simple return + values (?) + + Whenever a W register is written, the top half of the X register is zeroed. + */ + +static int +slp_switch(void) +{ + int err; + void *fp; + /* Windowz uses a 32-bit long on a 64-bit platform, unlike the rest of + the world, and in theory we can be compiled with GCC/llvm on 64-bit + windows. So we need a fixed-width type. + */ + int64_t *stackref, stsizediff; + __asm__ volatile ("" : : : REGS_TO_SAVE); + __asm__ volatile ("str x29, %0" : "=m"(fp) : : ); + __asm__ ("mov %0, sp" : "=r" (stackref)); + { + SLP_SAVE_STATE(stackref, stsizediff); + __asm__ volatile ( + "add sp,sp,%0\n" + "add x29,x29,%0\n" + : + : "r" (stsizediff) + ); + SLP_RESTORE_STATE(); + /* SLP_SAVE_STATE macro contains some return statements + (of -1 and 1). It falls through only when + the return value of slp_save_state() is zero, which + is placed in x0. + In that case we (slp_switch) also want to return zero + (also in x0 of course). + Now, some GCC versions (seen with 4.8) think it's a + good idea to save/restore x0 around the call to + slp_restore_state(), instead of simply zeroing it + at the return below. But slp_restore_state + writes random values to the stack slot used for this + save/restore (from when it once was saved above in + SLP_SAVE_STATE, when it was still uninitialized), so + "restoring" that precious zero actually makes us + return random values. There are some ways to make + GCC not use that zero value in the normal return path + (e.g. making err volatile, but that costs a little + stack space), and the simplest is to call a function + that returns an unknown value (which happens to be zero), + so the saved/restored value is unused. + + Thus, this line stores a 0 into the ``err`` variable + (which must be held in a register for this instruction, + of course). The ``w`` qualifier causes the instruction + to use W0 instead of X0, otherwise we get a warning + about a value size mismatch (because err is an int, + and aarch64 platforms are LP64: 32-bit int, 64 bit long + and pointer). + */ + __asm__ volatile ("mov %w0, #0" : "=r" (err)); + } + __asm__ volatile ("ldr x29, %0" : : "m" (fp) :); + __asm__ volatile ("" : : : REGS_TO_SAVE); + return err; +} + +#endif |