static int emulate_std()

in kernel/unaligned.c [345:433]

• 85 lines of code
• 4 McCabe index (conditional complexity)

static int emulate_std(struct pt_regs *regs, int frreg, int flop)
{
	__u64 val;
	int ret;

	if (flop)
		val = regs->fr[frreg];
	else if (frreg)
		val = regs->gr[frreg];
	else
		val = 0;

	DPRINTF("store r%d (0x%016llx) to " RFMT ":" RFMT " for 8 bytes\n", frreg, 
		val,  regs->isr, regs->ior);

#ifdef CONFIG_PA20
#ifndef CONFIG_64BIT
	if (!flop)
		return -1;
#endif
	__asm__ __volatile__ (
"	mtsp %3, %%sr1\n"
"	depd,z	%2, 60, 3, %%r19\n"
"	depd	%%r0, 63, 3, %2\n"
"	mtsar	%%r19\n"
"	depdi,z	-2, %%sar, 64, %%r19\n"
"1:	ldd	0(%%sr1,%2),%%r20\n"
"2:	ldd	8(%%sr1,%2),%%r21\n"
"	shrpd	%%r0, %1, %%sar, %%r22\n"
"	shrpd	%1, %%r0, %%sar, %%r1\n"
"	and	%%r20, %%r19, %%r20\n"
"	andcm	%%r21, %%r19, %%r21\n"
"	or	%%r22, %%r20, %%r20\n"
"	or	%%r1, %%r21, %%r21\n"
"3:	std	%%r20,0(%%sr1,%2)\n"
"4:	std	%%r21,8(%%sr1,%2)\n"
"	copy	%%r0, %0\n"
"5:	\n"
"	.section .fixup,\"ax\"\n"
"6:	ldi	-2, %0\n"
	FIXUP_BRANCH(5b)
"	.previous\n"
	ASM_EXCEPTIONTABLE_ENTRY(1b,6b)
	ASM_EXCEPTIONTABLE_ENTRY(2b,6b)
	ASM_EXCEPTIONTABLE_ENTRY(3b,6b)
	ASM_EXCEPTIONTABLE_ENTRY(4b,6b)
	: "=r" (ret)
	: "r" (val), "r" (regs->ior), "r" (regs->isr)
	: "r19", "r20", "r21", "r22", "r1", FIXUP_BRANCH_CLOBBER );
#else
    {
	unsigned long valh=(val>>32),vall=(val&0xffffffffl);
	__asm__ __volatile__ (
"	mtsp	%4, %%sr1\n"
"	zdep	%2, 29, 2, %%r19\n"
"	dep	%%r0, 31, 2, %2\n"
"	mtsar	%%r19\n"
"	zvdepi	-2, 32, %%r19\n"
"1:	ldw	0(%%sr1,%3),%%r20\n"
"2:	ldw	8(%%sr1,%3),%%r21\n"
"	vshd	%1, %2, %%r1\n"
"	vshd	%%r0, %1, %1\n"
"	vshd	%2, %%r0, %2\n"
"	and	%%r20, %%r19, %%r20\n"
"	andcm	%%r21, %%r19, %%r21\n"
"	or	%1, %%r20, %1\n"
"	or	%2, %%r21, %2\n"
"3:	stw	%1,0(%%sr1,%1)\n"
"4:	stw	%%r1,4(%%sr1,%3)\n"
"5:	stw	%2,8(%%sr1,%3)\n"
"	copy	%%r0, %0\n"
"6:	\n"
"	.section .fixup,\"ax\"\n"
"7:	ldi	-2, %0\n"
	FIXUP_BRANCH(6b)
"	.previous\n"
	ASM_EXCEPTIONTABLE_ENTRY(1b,7b)
	ASM_EXCEPTIONTABLE_ENTRY(2b,7b)
	ASM_EXCEPTIONTABLE_ENTRY(3b,7b)
	ASM_EXCEPTIONTABLE_ENTRY(4b,7b)
	ASM_EXCEPTIONTABLE_ENTRY(5b,7b)
	: "=r" (ret)
	: "r" (valh), "r" (vall), "r" (regs->ior), "r" (regs->isr)
	: "r19", "r20", "r21", "r1", FIXUP_BRANCH_CLOBBER );
    }
#endif

	return ret;
}