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//===-- xray_trampoline_x86.s -----------------------------------*- ASM -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is a part of XRay, a dynamic runtime instrumentation system.
//
// This implements the X86-specific assembler for the trampolines.
//
//===----------------------------------------------------------------------===//
.text
.file "xray_trampoline_x86.S"
.globl __xray_FunctionEntry
.align 16, 0x90
.type __xray_FunctionEntry,@function
__xray_FunctionEntry:
.cfi_startproc
// Save caller provided registers before doing any actual work.
pushq %rbp
.cfi_def_cfa_offset 16
subq $72, %rsp
movq %rdi, 64(%rsp)
movq %rax, 56(%rsp)
movq %rdx, 48(%rsp)
movq %rsi, 40(%rsp)
movq %rcx, 32(%rsp)
movq %r8, 24(%rsp)
movq %r9, 16(%rsp)
// de-mangled, that's __xray::XRayPatchedFunction, and we're doing an acquire
// load (on x86 is a normal mov instruction).
movq _ZN6__xray19XRayPatchedFunctionE(%rip), %rax
testq %rax, %rax
je .Ltmp0
// assume that %r10d has the function id.
movl %r10d, %edi
xor %esi,%esi
callq *%rax
.Ltmp0:
// restore the registers
movq 64(%rsp), %rdi
movq 56(%rsp), %rax
movq 48(%rsp), %rdx
movq 40(%rsp), %rsi
movq 32(%rsp), %rcx
movq 24(%rsp), %r8
movq 16(%rsp), %r9
addq $72, %rsp
popq %rbp
retq
.Ltmp1:
.size __xray_FunctionEntry, .Ltmp1-__xray_FunctionEntry
.cfi_endproc
.globl __xray_FunctionExit
.align 16, 0x90
.type __xray_FunctionExit,@function
__xray_FunctionExit:
.cfi_startproc
// Save the important registers first. Since we're assuming that this
// function is only jumped into, we only preserve the registers for
// returning.
// FIXME: Figure out whether this is sufficient.
pushq %rbp
.cfi_def_cfa_offset 16
subq $24, %rsp
.cfi_def_cfa_offset 32
movq %rax, 16(%rsp)
movq %rdx, 8(%rsp)
movq _ZN6__xray19XRayPatchedFunctionE(%rip), %rax
testq %rax,%rax
je .Ltmp2
movl %r10d, %edi
movl $1, %esi
callq *%rax
.Ltmp2:
// Restore the important registers.
movq 16(%rsp), %rax
movq 8(%rsp), %rdx
addq $24, %rsp
popq %rbp
retq
.Ltmp3:
.size __xray_FunctionExit, .Ltmp3-__xray_FunctionExit
.cfi_endproc
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