about summary refs log tree commit diff
path: root/src/setjmp/x86_64/longjmp.s
diff options
context:
space:
mode:
Diffstat (limited to 'src/setjmp/x86_64/longjmp.s')
-rw-r--r--src/setjmp/x86_64/longjmp.s24
1 files changed, 24 insertions, 0 deletions
diff --git a/src/setjmp/x86_64/longjmp.s b/src/setjmp/x86_64/longjmp.s
new file mode 100644
index 00000000..c63b0c95
--- /dev/null
+++ b/src/setjmp/x86_64/longjmp.s
@@ -0,0 +1,24 @@
+/* Copyright 2011 Nicholas J. Kain, licensed GNU LGPL 2.1 or later */
+.global _longjmp
+.global longjmp
+.type _longjmp,%function
+.type longjmp,%function
+_longjmp:
+longjmp:
+	mov %rsi,%rax           /* val will be longjmp return */
+	test %rax,%rax
+	jnz .L0
+	inc %rax                /* if val==0, val=1 per longjmp semantics */
+.L0:
+	movq (%rdi),%rbx        /* rdi is the jmp_buf, restore regs from it */
+	movq 8(%rdi),%rbp
+	movq 16(%rdi),%r12
+	movq 24(%rdi),%r13
+	movq 32(%rdi),%r14
+	movq 40(%rdi),%r15
+	movq 48(%rdi),%rdx      /* this ends up being the stack pointer */
+	mov %rdx,%rsp
+	movq 56(%rdi),%rdx      /* this is the instruction pointer */
+	jmp *%rdx               /* goto saved address without altering rsp */
+.size _longjmp,.-_longjmp
+.size longjmp,.-longjmp