newlib-cygwin/newlib/libc/machine/nds32/setjmp.S

/*
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The setjmp/longjmp for nds32.
The usage of thirty-two 32-bit General Purpose Registers (GPR):
  $r28 : $fp
  $r29 : $gp
  $r30 : $lp
  $r31 : $sp

  caller-save registers: $r0 ~ $r5, $r16 ~ $r23
  callee-save registers: $r6 ~ $r10, $r11 ~ $r14
  reserved for assembler : $r15
  reserved for other use : $r24, $r25, $r26, $r27

Save all callee-save registers and $fp, $gp, $lp and $sp is enough in theory.
For debugging issue, the layout of jum_buf in here should be in sync with GDB.
The $r16 ~ $r19 are used to store D0/D1, keep them for backward-compatible.
*/

/* int setjmp(jmp_buf env);  */
	.text
	.align	2
	.global	setjmp
	.type	setjmp, @function
setjmp:
#ifdef __NDS32_REDUCED_REGS__
	smw.bim	$r6, [$r0], $r10, #0b0000
	addi	$r0, $r0, #32	/* Leave room to keep jum_buf all the same.  */
	smw.bim	$r31, [$r0], $r31, #0b1111
#else
	smw.bim	$r6, [$r0], $r14, #0b0000
	smw.bim	$r16, [$r0], $r19, #0b1111
#endif

	/* Set return value to zero.  */
	movi	$r0, 0
	ret
	.size	setjmp, .-setjmp


/* void longjmp(jmp_buf env, int val);  */
	.text
	.align	2
	.global	longjmp
	.type	longjmp, @function
longjmp:
#ifdef __NDS32_REDUCED_REGS__
	lmw.bim	$r6, [$r0], $r10, #0b0000
	addi    $r0, $r0, #32
	lmw.bim	$r31, [$r0], $r31, #0b1111
#else
	lmw.bim	$r6, [$r0], $r14, #0b0000
	lmw.bim	$r16, [$r0], $r19, #0b1111
#endif
	/* Set val as return value.  If the value val is 0, 1 will be returned
	   instead.  */
	movi	$r0, 1
	cmovn	$r0, $r1, $r1	/* r0=(r1!=0)? r1: r0  */
	ret
	.size	longjmp, .-longjmp