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/* FIXME: this works locally but not on appveyor??!? */
/* NOTE: fastcall calling convention used on all x86 targets */
.text
.def @rust_psm_stack_direction@0
.scl 2
.type 32
.endef
.globl @rust_psm_stack_direction@0
.p2align 4
@rust_psm_stack_direction@0:
/* extern "fastcall" fn() -> u8 (%al) */
.cfi_startproc
movb $2, %al # always descending on x86_64
retl
.cfi_endproc
.def @rust_psm_stack_pointer@0
.scl 2
.type 32
.endef
.globl @rust_psm_stack_pointer@0
.p2align 4
@rust_psm_stack_pointer@0:
/* extern "fastcall" fn() -> *mut u8 (%rax) */
.cfi_startproc
leal 4(%esp), %eax
retl
.cfi_endproc
.def @rust_psm_replace_stack@16
.scl 2
.type 32
.endef
.globl @rust_psm_replace_stack@16
.p2align 4
@rust_psm_replace_stack@16:
/* extern "fastcall" fn(%ecx: usize, %edx: extern "fastcall" fn(usize), 4(%esp): *mut u8) */
.cfi_startproc
/*
All we gotta do is set the stack pointer to 4(%esp) & tail-call the callback in %edx
Note, that the callee expects the stack to be offset by 4 bytes (normally, a return address
would be store there) off the required stack alignment on entry. To offset the stack in such a
way we use the `calll` instruction, however it would also be possible to to use plain `jmpl` but
would require to adjust the stack manually, which cannot be easily done, because the stack
pointer argument is already stored in memory.
*/
movl 8(%esp), %eax
mov %eax, %fs:0x08
movl 4(%esp), %esp
mov %esp, %fs:0x04
calll *%edx
ud2
.cfi_endproc
.def @rust_psm_on_stack@16
.scl 2
.type 32
.endef
.globl @rust_psm_on_stack@16
.p2align 4
@rust_psm_on_stack@16:
/* extern "fastcall" fn(%ecx: usize, %edx: usize, 4(%esp): extern "fastcall" fn(usize, usize), 8(%esp): *mut u8) */
.cfi_startproc
pushl %ebp
.cfi_def_cfa %esp, 8
.cfi_offset %ebp, -8
pushl %fs:0x04
.cfi_def_cfa %esp, 12
pushl %fs:0x08
.cfi_def_cfa %esp, 16
movl %esp, %ebp
.cfi_def_cfa_register %ebp
movl 24(%ebp), %eax
movl %eax, %fs:0x08
movl 20(%ebp), %esp
movl %esp, %fs:0x04
calll *16(%ebp)
movl %ebp, %esp
popl %fs:0x08
.cfi_def_cfa %esp, 12
popl %fs:0x04
.cfi_def_cfa %esp, 8
popl %ebp
.cfi_def_cfa %esp, 4
retl $12
.cfi_endproc
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