diff options
author | Alexey Samsonov <samsonov@google.com> | 2014-02-14 09:20:33 +0000 |
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committer | Alexey Samsonov <samsonov@google.com> | 2014-02-14 09:20:33 +0000 |
commit | 53aa4fda49f94920139300227786ac47c393f1ce (patch) | |
tree | 6d022d04ee279fe1afd89668f346e28a9e3e1559 /lib/builtins/trampoline_setup.c | |
parent | 6d999e478fecb10dc43f20b85385d25cc239db0a (diff) |
Move original compiler-rt functions (libgcc replacement) to lib/builtins directory
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@201393 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/builtins/trampoline_setup.c')
-rw-r--r-- | lib/builtins/trampoline_setup.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/lib/builtins/trampoline_setup.c b/lib/builtins/trampoline_setup.c new file mode 100644 index 000000000..e0765b16b --- /dev/null +++ b/lib/builtins/trampoline_setup.c @@ -0,0 +1,47 @@ +/* ===----- 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. + * + * ===----------------------------------------------------------------------=== + */ + +#include "int_lib.h" + +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. + */ + +#if __ppc__ && !defined(__powerpc64__) +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__) */ |