/*
 * Copyright 2018-2025 Yury Gribov
 *
 * The MIT License (MIT)
 *
 * Use of this source code is governed by MIT license that can be
 * found in the LICENSE.txt file.
 */

  .section .note.GNU-stack,"",%progbits

  .data

  .globl _${lib_suffix}_tramp_table
  .hidden _${lib_suffix}_tramp_table
  .align 4
_${lib_suffix}_tramp_table:
  .zero $table_size

  .text

  .globl _${lib_suffix}_tramp_resolve
  .hidden _${lib_suffix}_tramp_resolve

  .globl _${lib_suffix}_save_regs_and_resolve
  .hidden _${lib_suffix}_save_regs_and_resolve
  .type _${lib_suffix}_save_regs_and_resolve, %function
_${lib_suffix}_save_regs_and_resolve:
  .cfi_startproc

#define PUSH_REG(reg) push {reg}; .cfi_adjust_cfa_offset 4; .cfi_rel_offset reg, 0
#define POP_REG(reg) pop {reg} ; .cfi_adjust_cfa_offset -4; .cfi_restore reg

// Binutils 2.30 does not like q0 in .cfi_rel_offset
#define PUSH_DREG_PAIR(reg1, reg2) vpush {reg1, reg2}; .cfi_adjust_cfa_offset 16; .cfi_rel_offset reg1, 0; .cfi_rel_offset reg2, 8
#define POP_DREG_PAIR(reg1, reg2) vpop {reg1, reg2}; .cfi_adjust_cfa_offset -16; .cfi_restore reg1; .cfi_restore reg2

  // Slow path which calls dlsym, taken only on first call.
  // Registers are saved acc. to "Procedure Call Standard for the ARM Architecture".
  // For DWARF directives, read https://www.imperialviolet.org/2017/01/18/cfi.html.

  // Stack is aligned at 16 bytes at this point

  // Save only arguments (and lr)
  PUSH_REG(r0)
  ldr r0, [sp, #8]
  PUSH_REG(r1)
  PUSH_REG(r2)
  PUSH_REG(r3)
  PUSH_REG(lr)
  PUSH_REG(lr)  // Align to 8 bytes

  // Arguments can be passed in VFP registers only when hard-float ABI is used
  // for arm-gnueabihf target // (http://android-doc.github.io/ndk/guides/abis.html#v7a).
  // Use compiler macro to detect this case.
#ifdef __ARM_PCS_VFP
  PUSH_DREG_PAIR(d0, d1)
  PUSH_DREG_PAIR(d2, d3)
  PUSH_DREG_PAIR(d4, d5)
  PUSH_DREG_PAIR(d6, d7)
  PUSH_DREG_PAIR(d8, d9)
  PUSH_DREG_PAIR(d10, d11)
  PUSH_DREG_PAIR(d12, d13)
  PUSH_DREG_PAIR(d14, d15)
  // FIXME: NEON actually supports 32 D-registers but it's unclear how to detect this
#endif

  bl _${lib_suffix}_tramp_resolve(PLT)
  mov ip, r0

#ifdef __ARM_PCS_VFP
  POP_DREG_PAIR(d14, d15)
  POP_DREG_PAIR(d12, d13)
  POP_DREG_PAIR(d10, d11)
  POP_DREG_PAIR(d8, d9)
  POP_DREG_PAIR(d6, d7)
  POP_DREG_PAIR(d4, d5)
  POP_DREG_PAIR(d2, d3)
  POP_DREG_PAIR(d0, d1)
#endif

  POP_REG(lr)  // TODO: pop pc?
  POP_REG(lr)
  POP_REG(r3)
  POP_REG(r2)
  POP_REG(r1)
  POP_REG(r0)

  bx lr

  .cfi_endproc