| 1 | //===-- Implementation of setjmp ------------------------------------------===// |
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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 "src/__support/common.h" |
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| 10 | #include "src/__support/macros/config.h" |
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| 11 | #include "src/setjmp/setjmp_impl.h" |
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| 12 | |
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| 13 | namespace LIBC_NAMESPACE_DECL { |
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| 14 | |
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| 15 | #if defined(__thumb__) && __ARM_ARCH_ISA_THUMB == 1 |
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| 16 | |
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| 17 | [[gnu::naked, gnu::target("thumb" )]] LLVM_LIBC_FUNCTION(int, setjmp, |
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| 18 | (jmp_buf buf)) { |
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| 19 | asm(R"( |
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| 20 | # Store r4, r5, r6, and r7 into buf. |
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| 21 | stmia r0!, {r4-r7} |
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| 22 | |
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| 23 | # Store r8, r9, r10, r11, sp, and lr into buf. Thumb(1) doesn't support |
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| 24 | # the high registers > r7 in stmia, so move them into lower GPRs first. |
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| 25 | # Thumb(1) also doesn't support using str with sp or lr, move them |
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| 26 | # together with the rest. |
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| 27 | mov r1, r8 |
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| 28 | mov r2, r9 |
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| 29 | mov r3, r10 |
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| 30 | stmia r0!, {r1-r3} |
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| 31 | |
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| 32 | mov r1, r11 |
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| 33 | mov r2, sp |
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| 34 | mov r3, lr |
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| 35 | stmia r0!, {r1-r3} |
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| 36 | |
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| 37 | # Return 0. |
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| 38 | movs r0, #0 |
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| 39 | bx lr)" ); |
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| 40 | } |
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| 41 | |
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| 42 | #else // Thumb2 or ARM |
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| 43 | |
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| 44 | // TODO(https://github.com/llvm/llvm-project/issues/94061): fp registers |
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| 45 | // (d0-d16) |
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| 46 | // TODO(https://github.com/llvm/llvm-project/issues/94062): pac+bti |
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| 47 | [[gnu::naked]] LLVM_LIBC_FUNCTION(int, setjmp, (jmp_buf buf)) { |
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| 48 | asm(R"( |
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| 49 | # While sp may appear in a register list for ARM mode, it may not for |
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| 50 | # Thumb2 mode. Just move it into r12 then stm that, so that this code |
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| 51 | # is portable between ARM and Thumb2. |
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| 52 | mov r12, sp |
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| 53 | |
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| 54 | # Store r4, r5, r6, r7, r8, r9, r10, r11, sp, and lr into buf. |
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| 55 | stm r0, {r4-r12, lr} |
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| 56 | |
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| 57 | # Return zero. |
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| 58 | mov r0, #0 |
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| 59 | bx lr)" ); |
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| 60 | } |
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| 61 | |
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| 62 | #endif |
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| 63 | |
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| 64 | } // namespace LIBC_NAMESPACE_DECL |
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| 65 | |
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