1214152Sed/* ===----- trampoline_setup.c - Implement __trampoline_setup -------------=== 2214152Sed * 3214152Sed * The LLVM Compiler Infrastructure 4214152Sed * 5222656Sed * This file is dual licensed under the MIT and the University of Illinois Open 6222656Sed * Source Licenses. See LICENSE.TXT for details. 7214152Sed * 8214152Sed * ===----------------------------------------------------------------------=== 9214152Sed */ 10214152Sed 11214152Sed#include "int_lib.h" 12214152Sed 13214152Sedextern void __clear_cache(void* start, void* end); 14214152Sed 15214152Sed/* 16214152Sed * The ppc compiler generates calls to __trampoline_setup() when creating 17214152Sed * trampoline functions on the stack for use with nested functions. 18214152Sed * This function creates a custom 40-byte trampoline function on the stack 19214152Sed * which loads r11 with a pointer to the outer function's locals 20214152Sed * and then jumps to the target nested function. 21214152Sed */ 22214152Sed 23215125Sed#if __ppc__ && !defined(__powerpc64__) 24214152Sedvoid __trampoline_setup(uint32_t* trampOnStack, int trampSizeAllocated, 25214152Sed const void* realFunc, void* localsPtr) 26214152Sed{ 27214152Sed /* should never happen, but if compiler did not allocate */ 28214152Sed /* enough space on stack for the trampoline, abort */ 29214152Sed if ( trampSizeAllocated < 40 ) 30214152Sed compilerrt_abort(); 31214152Sed 32214152Sed /* create trampoline */ 33214152Sed trampOnStack[0] = 0x7c0802a6; /* mflr r0 */ 34214152Sed trampOnStack[1] = 0x4800000d; /* bl Lbase */ 35214152Sed trampOnStack[2] = (uint32_t)realFunc; 36214152Sed trampOnStack[3] = (uint32_t)localsPtr; 37214152Sed trampOnStack[4] = 0x7d6802a6; /* Lbase: mflr r11 */ 38214152Sed trampOnStack[5] = 0x818b0000; /* lwz r12,0(r11) */ 39214152Sed trampOnStack[6] = 0x7c0803a6; /* mtlr r0 */ 40214152Sed trampOnStack[7] = 0x7d8903a6; /* mtctr r12 */ 41214152Sed trampOnStack[8] = 0x816b0004; /* lwz r11,4(r11) */ 42214152Sed trampOnStack[9] = 0x4e800420; /* bctr */ 43214152Sed 44214152Sed /* clear instruction cache */ 45214152Sed __clear_cache(trampOnStack, &trampOnStack[10]); 46214152Sed} 47229413Sed#endif /* __ppc__ && !defined(__powerpc64__) */ 48