diff options
Diffstat (limited to 'lib/builtins/trampoline_setup.c')
| -rw-r--r-- | lib/builtins/trampoline_setup.c | 77 |
1 files changed, 36 insertions, 41 deletions
diff --git a/lib/builtins/trampoline_setup.c b/lib/builtins/trampoline_setup.c index 25b627ab7..a62431723 100644 --- a/lib/builtins/trampoline_setup.c +++ b/lib/builtins/trampoline_setup.c @@ -1,48 +1,43 @@ -/* ===----- trampoline_setup.c - Implement __trampoline_setup -------------=== - * - * The LLVM Compiler Infrastructure - * - * This file is dual licensed under the MIT and the University of Illinois Open - * Source Licenses. See LICENSE.TXT for details. - * - * ===----------------------------------------------------------------------=== - */ +//===----- trampoline_setup.c - Implement __trampoline_setup -------------===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// #include "int_lib.h" -extern void __clear_cache(void* start, void* end); +extern void __clear_cache(void *start, void *end); -/* - * The ppc compiler generates calls to __trampoline_setup() when creating - * trampoline functions on the stack for use with nested functions. - * This function creates a custom 40-byte trampoline function on the stack - * which loads r11 with a pointer to the outer function's locals - * and then jumps to the target nested function. - */ +// The ppc compiler generates calls to __trampoline_setup() when creating +// trampoline functions on the stack for use with nested functions. +// This function creates a custom 40-byte trampoline function on the stack +// which loads r11 with a pointer to the outer function's locals +// and then jumps to the target nested function. #if __ppc__ && !defined(__powerpc64__) -COMPILER_RT_ABI void -__trampoline_setup(uint32_t* trampOnStack, int trampSizeAllocated, - const void* realFunc, void* localsPtr) -{ - /* should never happen, but if compiler did not allocate */ - /* enough space on stack for the trampoline, abort */ - if ( trampSizeAllocated < 40 ) - compilerrt_abort(); - - /* create trampoline */ - trampOnStack[0] = 0x7c0802a6; /* mflr r0 */ - trampOnStack[1] = 0x4800000d; /* bl Lbase */ - trampOnStack[2] = (uint32_t)realFunc; - trampOnStack[3] = (uint32_t)localsPtr; - trampOnStack[4] = 0x7d6802a6; /* Lbase: mflr r11 */ - trampOnStack[5] = 0x818b0000; /* lwz r12,0(r11) */ - trampOnStack[6] = 0x7c0803a6; /* mtlr r0 */ - trampOnStack[7] = 0x7d8903a6; /* mtctr r12 */ - trampOnStack[8] = 0x816b0004; /* lwz r11,4(r11) */ - trampOnStack[9] = 0x4e800420; /* bctr */ - - /* clear instruction cache */ - __clear_cache(trampOnStack, &trampOnStack[10]); +COMPILER_RT_ABI void __trampoline_setup(uint32_t *trampOnStack, + int trampSizeAllocated, + const void *realFunc, void *localsPtr) { + // should never happen, but if compiler did not allocate + // enough space on stack for the trampoline, abort + if (trampSizeAllocated < 40) + compilerrt_abort(); + + // create trampoline + trampOnStack[0] = 0x7c0802a6; // mflr r0 + trampOnStack[1] = 0x4800000d; // bl Lbase + trampOnStack[2] = (uint32_t)realFunc; + trampOnStack[3] = (uint32_t)localsPtr; + trampOnStack[4] = 0x7d6802a6; // Lbase: mflr r11 + trampOnStack[5] = 0x818b0000; // lwz r12,0(r11) + trampOnStack[6] = 0x7c0803a6; // mtlr r0 + trampOnStack[7] = 0x7d8903a6; // mtctr r12 + trampOnStack[8] = 0x816b0004; // lwz r11,4(r11) + trampOnStack[9] = 0x4e800420; // bctr + + // clear instruction cache + __clear_cache(trampOnStack, &trampOnStack[10]); } -#endif /* __ppc__ && !defined(__powerpc64__) */ +#endif // __ppc__ && !defined(__powerpc64__) |