1//===-- save_restore_regs.S - Implement save/restore* ---------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. 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//
28DEFINE_COMPILERRT_PRIVATE_FUNCTION(__save_vfp_d8_d15_regs)
29	vstmdb	sp!, {d8-d15}           // push registers d8-d15 onto stack
30	bx      lr                      // return to prolog
31
32	// tell linker it can break up file at label boundaries
33	.subsections_via_symbols
34
35