Mercurial > pub > dyncall > dyncall
view dyncall/dyncall_call_arm32_thumb_gas.s @ 474:c9e19249ecd3
- doc: sparc64 disas examples and doc additions regarding aggregates
author | Tassilo Philipp |
---|---|
date | Wed, 16 Feb 2022 19:26:21 +0100 |
parents | 351bb41d3bb1 |
children |
line wrap: on
line source
/* Package: dyncall Library: dyncall File: dyncall/dyncall_call_arm32_thumb_gas.s Description: ARM Thumb call kernel implementation for GNU assembler. License: Copyright (c) 2007-2021 Daniel Adler <dadler@uni-goettingen.de>, Tassilo Philipp <tphilipp@potion-studios.com> Permission to use, copy, modify, and distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies. THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ .text #if !defined(__thumb2__) .code 16 /* THUMB mode */ #endif .globl dcCall_arm32_thumb /* Main dyncall call. */ .thumb_func dcCall_arm32_thumb: /* Prolog. This function never needs to spill inside its prolog, so just store the permanent registers. */ /* Code below is not using high registers, so not storing them in prolog, which is more involved with thumb, anyways. */ push {r4-r7, r14} /* Frame ptr, permanent registers, link register -> save area on stack. */ mov r7, r13 /* Set frame ptr. */ sub r13, #4 /* Realign stack to 8 bytes (b/c we stored 5 regs = 20b). */ /* Call. */ mov r4, r0 /* Move 'fptr' to r4 (1st argument is passed in r0). */ mov r5, r1 /* Move 'args' to r5 (2nd argument is passed in r1). */ mov r6, r2 /* Move 'size' to r6 (3rd argument is passed in r2). */ cmp r6, #16 /* Jump to call if no more than 4 arguments. */ ble call sub r6, #16 /* Size of remaining arguments. */ mov r0, r13 /* Set stack pointer to top of stack. */ sub r0, r0, r6 lsr r0, #3 /* Align stack on 8 byte boundaries. */ lsl r0, #3 mov r13, r0 add r1, #16 /* Let r1 point to remaining arguments. */ mov r2, #0 /* Init byte counter to 0. */ .thumb_func pushArgs: ldrb r3, [r1, r2] /* Load a byte into r3. */ strb r3, [r0, r2] /* Push byte onto stack. */ add r2, r2, #1 /* Increment byte counter. */ cmp r2, r6 bne pushArgs .thumb_func call: ldmia r5!, {r0-r3} /* Load first 4 arguments for new call into r0-r3. */ /* 'blx r4' workaround for ARMv4t in THUMB: */ mov r6, r15 /* Load PC+2 instructions from here */ add r6, #5 /* Increment by 2 instructions (Address of 'Epilog') and set bit 0 (THUMB) */ mov r14, r6 /* Store in link register. */ bx r4 /* Branch and force THUMB-mode return (LR bit 0 set). */ /* Epilog. */ mov r13, r7 /* Reset stack ptr. */ pop {r4-r7, r15} /* Restore permanent registers and program counter. (Force a stay in THUMB in ARMv4, whether ARMv5 can return in ARM or THUMB depending on the bit 0. */