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-rw-r--r--src/libc/setjmp.s39
1 files changed, 39 insertions, 0 deletions
diff --git a/src/libc/setjmp.s b/src/libc/setjmp.s
new file mode 100644
index 0000000..29292da
--- /dev/null
+++ b/src/libc/setjmp.s
@@ -0,0 +1,39 @@
+.section .text
+.global setjmp
+.type setjmp, @function
+// int setjmp(jmp_buf env);
+setjmp:
+ mov %rbx, 0(%rdi)
+ mov %rbp, 16(%rdi)
+ mov %r12, 24(%rdi)
+ mov %r13, 32(%rdi)
+ mov %r14, 40(%rdi)
+ mov %r15, 48(%rdi)
+ /* save registers as if after a ret */
+ lea 8(%rsp), %rax
+ mov %rax, 8(%rdi)
+ mov (%rsp), %rax
+ mov %rax, 56(%rdi)
+ xor %rax, %rax
+
+ mov 8(%rdi), %rsp
+ jmp *56(%rdi)
+
+ ret
+
+
+.global longjmp
+.type longjmp, @function
+// _Noreturn void longjmp(jmp_buf env, int val);
+longjmp:
+ mov %rsi, %rax
+ cmp $1, %rax /* carry set as for %rax - 1 - so, 1 only if %rax == 0 */
+ adc $0, %rax
+1: mov 0(%rdi), %rbx
+ mov 8(%rdi), %rsp
+ mov 16(%rdi), %rbp
+ mov 24(%rdi), %r12
+ mov 32(%rdi), %r13
+ mov 40(%rdi), %r14
+ mov 48(%rdi), %r15
+ jmp *56(%rdi)