1 //===-- save_restore_regs.S - Implement save/restore* ---------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #include "../assembly.h" 11 12 // 13 // When compiling C++ functions that need to handle thrown exceptions the 14 // compiler is required to save all registers and call __Unwind_SjLj_Register 15 // in the function prolog. But when compiling for thumb1, there are 16 // no instructions to access the floating point registers, so the 17 // compiler needs to add a call to the helper function _save_vfp_d8_d15_regs 18 // written in ARM to save the float registers. In the epilog, the compiler 19 // must also add a call to __restore_vfp_d8_d15_regs to restore those registers. 20 // 21 22 .text 23 .syntax unified 24 25 // 26 // Save registers d8-d15 onto stack 27 // 28 .align 2 29 DEFINE_COMPILERRT_PRIVATE_FUNCTION(__save_vfp_d8_d15_regs) 30 vstmdb sp!, {d8-d15} // push registers d8-d15 onto stack 31 bx lr // return to prolog 32 33 // tell linker it can break up file at label boundaries 34 .subsections_via_symbols 35 36
