| 1 | //===-- save_restore_regs.S - Implement save/restore* ---------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | #include "../assembly.h" |
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| 10 | |
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| 11 | // |
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| 12 | // When compiling C++ functions that need to handle thrown exceptions the |
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| 13 | // compiler is required to save all registers and call __Unwind_SjLj_Register |
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| 14 | // in the function prolog. But when compiling for thumb1, there are |
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| 15 | // no instructions to access the floating point registers, so the |
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| 16 | // compiler needs to add a call to the helper function _save_vfp_d8_d15_regs |
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| 17 | // written in ARM to save the float registers. In the epilog, the compiler |
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| 18 | // must also add a call to __restore_vfp_d8_d15_regs to restore those registers. |
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| 19 | // |
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| 20 | |
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| 21 | .text |
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| 22 | .syntax unified |
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| 23 | |
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| 24 | // |
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| 25 | // Restore registers d8-d15 from stack |
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| 26 | // |
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| 27 | .p2align 2 |
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| 28 | DEFINE_COMPILERRT_PRIVATE_FUNCTION(__restore_vfp_d8_d15_regs) |
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| 29 | vldmia sp!, {d8-d15} // pop registers d8-d15 off stack |
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| 30 | bx lr // return to prolog |
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| 31 | END_COMPILERRT_FUNCTION(__restore_vfp_d8_d15_regs) |
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| 32 | |
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| 33 | NO_EXEC_STACK_DIRECTIVE |
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| 34 | |
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| 35 | |
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