1353358Sdim//===----- trampoline_setup.c - Implement __trampoline_setup -------------===// 2353358Sdim// 3353358Sdim// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4353358Sdim// See https://llvm.org/LICENSE.txt for license information. 5353358Sdim// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6353358Sdim// 7353358Sdim//===----------------------------------------------------------------------===// 8276789Sdim 9276789Sdim#include "int_lib.h" 10276789Sdim 11353358Sdimextern void __clear_cache(void *start, void *end); 12276789Sdim 13353358Sdim// The ppc compiler generates calls to __trampoline_setup() when creating 14353358Sdim// trampoline functions on the stack for use with nested functions. 15353358Sdim// This function creates a custom 40-byte trampoline function on the stack 16353358Sdim// which loads r11 with a pointer to the outer function's locals 17353358Sdim// and then jumps to the target nested function. 18276789Sdim 19276789Sdim#if __ppc__ && !defined(__powerpc64__) 20353358SdimCOMPILER_RT_ABI void __trampoline_setup(uint32_t *trampOnStack, 21353358Sdim int trampSizeAllocated, 22353358Sdim const void *realFunc, void *localsPtr) { 23353358Sdim // should never happen, but if compiler did not allocate 24353358Sdim // enough space on stack for the trampoline, abort 25353358Sdim if (trampSizeAllocated < 40) 26353358Sdim compilerrt_abort(); 27353358Sdim 28353358Sdim // create trampoline 29353358Sdim trampOnStack[0] = 0x7c0802a6; // mflr r0 30353358Sdim trampOnStack[1] = 0x4800000d; // bl Lbase 31353358Sdim trampOnStack[2] = (uint32_t)realFunc; 32353358Sdim trampOnStack[3] = (uint32_t)localsPtr; 33353358Sdim trampOnStack[4] = 0x7d6802a6; // Lbase: mflr r11 34353358Sdim trampOnStack[5] = 0x818b0000; // lwz r12,0(r11) 35353358Sdim trampOnStack[6] = 0x7c0803a6; // mtlr r0 36353358Sdim trampOnStack[7] = 0x7d8903a6; // mtctr r12 37353358Sdim trampOnStack[8] = 0x816b0004; // lwz r11,4(r11) 38353358Sdim trampOnStack[9] = 0x4e800420; // bctr 39353358Sdim 40353358Sdim // clear instruction cache 41353358Sdim __clear_cache(trampOnStack, &trampOnStack[10]); 42276789Sdim} 43353358Sdim#endif // __ppc__ && !defined(__powerpc64__) 44