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      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 // Restore registers d8-d15 from stack
     27 //
     28 	.p2align 2
     29 DEFINE_COMPILERRT_PRIVATE_FUNCTION(__restore_vfp_d8_d15_regs)
     30 	vldmia	sp!, {d8-d15}           // pop registers d8-d15 off stack
     31 	bx      lr                      // return to prolog
     32 END_COMPILERRT_FUNCTION(__restore_vfp_d8_d15_regs)
     33 
     34