/* SPDX-License-Identifier: MPL-1.1 OR GPL-2.0-or-later */

/* If user disable the ASM, such as avoiding bugs in ASM, donot compile it. */
#if !defined(MD_ST_NO_ASM)

/*
 * Portions created by SGI are Copyright (C) 2000 Silicon Graphics, Inc.
 * All Rights Reserved.
 */

#if defined(__i386__)

    /****************************************************************/

    /*
     * Internal __jmp_buf layout
     */
    #define JB_BX  0
    #define JB_SI  1
    #define JB_DI  2
    #define JB_BP  3
    #define JB_SP  4
    #define JB_PC  5

    .file "md.S"
    .text

    /* _st_md_cxt_save(__jmp_buf env) */
    .globl _st_md_cxt_save
        .type _st_md_cxt_save, @function
        .align 16
    _st_md_cxt_save:
        movl 4(%esp), %eax

        /*
         * Save registers.
         */
        movl %ebx, (JB_BX*4)(%eax)
        movl %esi, (JB_SI*4)(%eax)
        movl %edi, (JB_DI*4)(%eax)
        /* Save SP */
        leal 4(%esp), %ecx
        movl %ecx, (JB_SP*4)(%eax)
        /* Save PC we are returning to */
        movl 0(%esp), %ecx
        movl %ecx, (JB_PC*4)(%eax)
        /* Save caller frame pointer */
        movl %ebp, (JB_BP*4)(%eax)
        xorl %eax, %eax
        ret
    .size _st_md_cxt_save, .-_st_md_cxt_save


    /****************************************************************/

    /* _st_md_cxt_restore(__jmp_buf env, int val) */
    .globl _st_md_cxt_restore
        .type _st_md_cxt_restore, @function
        .align 16
    _st_md_cxt_restore:
        /* First argument is jmp_buf */
        movl 4(%esp), %ecx
        /* Second argument is return value */
        movl 8(%esp), %eax
        /* Set the return address */
        movl (JB_PC*4)(%ecx), %edx
        /*
         * Restore registers.
         */
        movl (JB_BX*4)(%ecx), %ebx
        movl (JB_SI*4)(%ecx), %esi
        movl (JB_DI*4)(%ecx), %edi
        movl (JB_BP*4)(%ecx), %ebp
        movl (JB_SP*4)(%ecx), %esp
        testl %eax, %eax
        jnz  1f
        incl %eax
        /* Jump to saved PC */
        1: jmp *%edx
    .size _st_md_cxt_restore, .-_st_md_cxt_restore

    /****************************************************************/










#elif defined(__amd64__) || defined(__x86_64__)

    /****************************************************************/

    /*
     * Internal __jmp_buf layout
     */
    #define JB_RBX  0
    #define JB_RBP  1
    #define JB_R12  2
    #define JB_R13  3
    #define JB_R14  4
    #define JB_R15  5
    #define JB_RSP  6
    #define JB_PC   7

    .file "md.S"
    .text

    /* _st_md_cxt_save(__jmp_buf env) */
    .globl _st_md_cxt_save
        .type _st_md_cxt_save, @function
        .align 16
    _st_md_cxt_save:
        /*
         * Save registers.
         */
        movq %rbx, (JB_RBX*8)(%rdi)
        movq %rbp, (JB_RBP*8)(%rdi)
        movq %r12, (JB_R12*8)(%rdi)
        movq %r13, (JB_R13*8)(%rdi)
        movq %r14, (JB_R14*8)(%rdi)
        movq %r15, (JB_R15*8)(%rdi)
        /* Save SP */
        leaq 8(%rsp), %rdx
        movq %rdx, (JB_RSP*8)(%rdi)
        /* Save PC we are returning to */
        movq (%rsp), %rax
        movq %rax, (JB_PC*8)(%rdi)
        xorq %rax, %rax
        ret
    .size _st_md_cxt_save, .-_st_md_cxt_save


    /****************************************************************/

    /* _st_md_cxt_restore(__jmp_buf env, int val) */
    .globl _st_md_cxt_restore
        .type _st_md_cxt_restore, @function
        .align 16
    _st_md_cxt_restore:
        /*
         * Restore registers.
         */
        movq (JB_RBX*8)(%rdi), %rbx
        movq (JB_RBP*8)(%rdi), %rbp
        movq (JB_R12*8)(%rdi), %r12
        movq (JB_R13*8)(%rdi), %r13
        movq (JB_R14*8)(%rdi), %r14
        movq (JB_R15*8)(%rdi), %r15
        /* Set return value */
        test %esi, %esi
        mov $01, %eax
        cmove %eax, %esi
        mov %esi, %eax
        movq (JB_PC*8)(%rdi), %rdx
        movq (JB_RSP*8)(%rdi), %rsp
        /* Jump to saved PC */
        jmpq *%rdx
    .size _st_md_cxt_restore, .-_st_md_cxt_restore

    /****************************************************************/










#elif defined(__aarch64__)

    /****************************************************************/
    /* https://github.com/ossrs/srs/issues/1282#issuecomment-445539513 */

    #define JB_X19            0
    #define JB_X20            1
    #define JB_X21            2
    #define JB_X22            3
    #define JB_X23            4
    #define JB_X24            5
    #define JB_X25            6
    #define JB_X26            7
    #define JB_X27            8
    #define JB_X28            9
    #define JB_X29           10
    #define JB_LR            11
    #define JB_SP		 13

    #define JB_D8		 14
    #define JB_D9		 15
    #define JB_D10		 16
    #define JB_D11		 17
    #define JB_D12		 18
    #define JB_D13		 19
    #define JB_D14		 20
    #define JB_D15		 21

    	.file "md.S"
    	.text

    	/* _st_md_cxt_save(__jmp_buf env) */
    	.globl _st_md_cxt_save
    	.type _st_md_cxt_save, %function
    	.align 4
    _st_md_cxt_save:
    	stp	x19, x20, [x0, #JB_X19<<3]
    	stp	x21, x22, [x0, #JB_X21<<3]
    	stp	x23, x24, [x0, #JB_X23<<3]
    	stp	x25, x26, [x0, #JB_X25<<3]
    	stp	x27, x28, [x0, #JB_X27<<3]
    	stp	x29, x30, [x0, #JB_X29<<3]

    	stp	 d8,  d9, [x0, #JB_D8<<3]
    	stp	d10, d11, [x0, #JB_D10<<3]
    	stp	d12, d13, [x0, #JB_D12<<3]
    	stp	d14, d15, [x0, #JB_D14<<3]
    	mov	x2,  sp
    	str	x2,  [x0, #JB_SP<<3]

    	mov	x0, #0
    	ret
    	.size _st_md_cxt_save, .-_st_md_cxt_save

    /****************************************************************/

    	/* _st_md_cxt_restore(__jmp_buf env, int val) */
    	.globl _st_md_cxt_restore
    	.type _st_md_cxt_restore, %function
    	.align 4
    _st_md_cxt_restore:
    	ldp	x19, x20, [x0, #JB_X19<<3]
    	ldp	x21, x22, [x0, #JB_X21<<3]
    	ldp	x23, x24, [x0, #JB_X23<<3]
    	ldp	x25, x26, [x0, #JB_X25<<3]
    	ldp	x27, x28, [x0, #JB_X27<<3]

    	ldp	x29, x30, [x0, #JB_X29<<3]

    	ldp	 d8,  d9, [x0, #JB_D8<<3]
    	ldp	d10, d11, [x0, #JB_D10<<3]
    	ldp	d12, d13, [x0, #JB_D12<<3]
    	ldp	d14, d15, [x0, #JB_D14<<3]

    	ldr	x5, [x0, #JB_SP<<3]
    	mov	sp, x5

    	cmp	x1, #0
    	mov	x0, #1
    	csel	x0, x1, x0, ne
    	/* Use br instead of ret because ret is guaranteed to mispredict */
    	br	x30
    	.size _st_md_cxt_restore, .-_st_md_cxt_restore

    /****************************************************************/










#elif defined(__arm__)

    /****************************************************************/
    /* https://github.com/ossrs/srs/issues/1282#issuecomment-445539513 */

    /* Register list for a ldm/stm instruction to load/store
       the general registers from a __jmp_buf.  */
    # define JMP_BUF_REGLIST	{v1-v6, sl, fp, sp, lr}

    	.file "md.S"
    	.text

    	/* _st_md_cxt_save(__jmp_buf env) */
    	.globl _st_md_cxt_save
    	.type _st_md_cxt_save, %function
    	.align 2
    _st_md_cxt_save:
    	mov	ip, r0

    	/* Save registers */
    	stmia	ip!, JMP_BUF_REGLIST

    #ifdef __VFP_FP__
    	/* Store the VFP registers.  */
    	/* Following instruction is vstmia ip!, {d8-d15}.  */
    	stc	p11, cr8, [ip], #64
    #endif

    #ifdef __IWMMXT__
    	/* Save the call-preserved iWMMXt registers.  */
    	/* Following instructions are wstrd wr10, [ip], #8 (etc.)  */
    	stcl	p1, cr10, [r12], #8
    	stcl	p1, cr11, [r12], #8
    	stcl	p1, cr12, [r12], #8
    	stcl	p1, cr13, [r12], #8
    	stcl	p1, cr14, [r12], #8
    	stcl	p1, cr15, [r12], #8
    #endif

    	mov	r0, #0
    	bx	lr

    	.size _st_md_cxt_save, .-_st_md_cxt_save

    /****************************************************************/

    	/* _st_md_cxt_restore(__jmp_buf env, int val) */
    	.globl _st_md_cxt_restore
    	.type _st_md_cxt_restore, %function
    	.align 2
    _st_md_cxt_restore:
    	mov	ip, r0

    	/* Restore registers */
    	ldmia	ip!, JMP_BUF_REGLIST

    #ifdef __VFP_FP__
    	/* Restore the VFP registers.  */
    	/* Following instruction is vldmia ip!, {d8-d15}.  */
    	ldc	p11, cr8, [r12], #64
    #endif

    #ifdef __IWMMXT__
    	/* Restore the call-preserved iWMMXt registers.  */
    	/* Following instructions are wldrd wr10, [ip], #8 (etc.)  */
    	ldcl	p1, cr10, [r12], #8
    	ldcl	p1, cr11, [r12], #8
    	ldcl	p1, cr12, [r12], #8
    	ldcl	p1, cr13, [r12], #8
    	ldcl	p1, cr14, [r12], #8
    	ldcl	p1, cr15, [r12], #8
    #endif

    	movs	r0, r1		/* get the return value in place */
    	moveq	r0, #1		/* can't let setjmp() return zero! */
    	bx	lr

    	.size _st_md_cxt_restore, .-_st_md_cxt_restore

    /****************************************************************/










#elif defined(__mips__)

    /****************************************************************/

    /*
     * Internal __jmp_buf layout
     */
    #define JB_SP  0    /* Stack pointer */
    #define JB_RA  11   /* Return address */
    #define JB_GP  1    /* Global pointer */
    #define JB_S0  3    /* S0-S7, Saved temporaries */
    #define JB_S1  4    /* S0-S7, Saved temporaries */
    #define JB_S2  5    /* S0-S7, Saved temporaries */
    #define JB_S3  6    /* S0-S7, Saved temporaries */
    #define JB_S4  7    /* S0-S7, Saved temporaries */
    #define JB_S5  8    /* S0-S7, Saved temporaries */
    #define JB_S6  9    /* S0-S7, Saved temporaries */
    #define JB_S7  10   /* S0-S7, Saved temporaries */
    #define JB_FP  2    /* FP/S8 Frame pointer */

    	.file "md_linux.S"
    	.text

    	/* _st_md_cxt_save(__jmp_buf env) */ /* The env is $a0, https://en.wikipedia.org/wiki/MIPS_architecture#Calling_conventions */
    	.globl _st_md_cxt_save
    	.type _st_md_cxt_save, %function
    	.align 2
    _st_md_cxt_save:
        sw $sp, 0($a0)  /* Save sp to env[0],  *(long*)($a0+0) =sp */
        sw $ra, 4($a0)  /* Save ra to env[1],  *(long*)($a0+4)=ra, the return address, https://chortle.ccsu.edu/AssemblyTutorial/Chapter-26/ass26_4.html */
        sw $gp, 8($a0)  /* Save gp to env[2],  *(long*)($a0+8) =gp */
        sw $s0, 12($a0) /* Save s0 to env[3],  *(long*)($a0+12)=s0 */
        sw $s1, 16($a0) /* Save s1 to env[4],  *(long*)($a0+16)=s1 */
        sw $s2, 20($a0) /* Save s2 to env[5],  *(long*)($a0+20)=s2 */
        sw $s3, 24($a0) /* Save s3 to env[6],  *(long*)($a0+24)=s3 */
        sw $s4, 28($a0) /* Save s4 to env[7],  *(long*)($a0+28)=s4 */
        sw $s5, 32($a0) /* Save s5 to env[8],  *(long*)($a0+32)=s5 */
        sw $s6, 36($a0) /* Save s6 to env[9],  *(long*)($a0+36)=s6 */
        sw $s7, 40($a0) /* Save s7 to env[10], *(long*)($a0+40)=s7 */
        sw $fp, 44($a0) /* Save fp to env[11], *(long*)($a0+44) =fp */
        li $v0, 0       /* Set return value to 0 */
        jr $ra          /* Return */

    	.size _st_md_cxt_save, .-_st_md_cxt_save

    /****************************************************************/

    	/* _st_md_cxt_restore(__jmp_buf env, int val) */
    	.globl _st_md_cxt_restore
    	.type _st_md_cxt_restore, %function
    	.align 2
    _st_md_cxt_restore:
        lw $sp, 0($a0)  /* Load sp from env[0],  sp=*(long*)($a0+0)  */
        lw $ra, 4($a0)  /* Load sp from env[1],  ra=*(long*)($a0+4), the saved return address */
        lw $gp, 8($a0)  /* Load sp from env[2],  gp=*(long*)($a0+8)  */
        lw $s0, 12($a0) /* Load sp from env[3],  s0=*(long*)($a0+12) */
        lw $s1, 16($a0) /* Load sp from env[4],  s1=*(long*)($a0+16) */
        lw $s2, 20($a0) /* Load sp from env[5],  s2=*(long*)($a0+20) */
        lw $s3, 24($a0) /* Load sp from env[6],  s3=*(long*)($a0+24) */
        lw $s4, 28($a0) /* Load sp from env[7],  s4=*(long*)($a0+28) */
        lw $s5, 32($a0) /* Load sp from env[8],  s5=*(long*)($a0+32) */
        lw $s6, 36($a0) /* Load sp from env[9],  s6=*(long*)($a0+36) */
        lw $s7, 40($a0) /* Load sp from env[10], s7=*(long*)($a0+40) */
        lw $fp, 44($a0) /* Load sp from env[2],  fp=*(long*)($a0+44)  */
        li $v0, 1       /* Set return value to 1 */
        jr $ra          /* Return to the saved return address */

    	.size _st_md_cxt_restore, .-_st_md_cxt_restore

    /****************************************************************/

#endif

#endif