407 lines
		
	
	
		
			8.5 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			407 lines
		
	
	
		
			8.5 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
#include <asm/processor.h>
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#include <asm/ppc_asm.h>
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#include <asm/reg.h>
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#include <asm/asm-offsets.h>
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#include <asm/cputable.h>
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#include <asm/thread_info.h>
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#include <asm/page.h>
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/*
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 * load_up_altivec(unused, unused, tsk)
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 * Disable VMX for the task which had it previously,
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 * and save its vector registers in its thread_struct.
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 * Enables the VMX for use in the kernel on return.
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 * On SMP we know the VMX is free, since we give it up every
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 * switch (ie, no lazy save of the vector registers).
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 */
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_GLOBAL(load_up_altivec)
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	mfmsr	r5			/* grab the current MSR */
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	oris	r5,r5,MSR_VEC@h
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	MTMSRD(r5)			/* enable use of AltiVec now */
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	isync
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/*
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 * For SMP, we don't do lazy VMX switching because it just gets too
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 * horrendously complex, especially when a task switches from one CPU
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 * to another.  Instead we call giveup_altvec in switch_to.
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 * VRSAVE isn't dealt with here, that is done in the normal context
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 * switch code. Note that we could rely on vrsave value to eventually
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 * avoid saving all of the VREGs here...
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 */
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#ifndef CONFIG_SMP
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	LOAD_REG_ADDRBASE(r3, last_task_used_altivec)
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	toreal(r3)
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	PPC_LL	r4,ADDROFF(last_task_used_altivec)(r3)
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	PPC_LCMPI	0,r4,0
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	beq	1f
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	/* Save VMX state to last_task_used_altivec's THREAD struct */
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	toreal(r4)
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	addi	r4,r4,THREAD
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	SAVE_32VRS(0,r5,r4)
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	mfvscr	vr0
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	li	r10,THREAD_VSCR
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	stvx	vr0,r10,r4
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	/* Disable VMX for last_task_used_altivec */
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	PPC_LL	r5,PT_REGS(r4)
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	toreal(r5)
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	PPC_LL	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
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	lis	r10,MSR_VEC@h
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	andc	r4,r4,r10
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	PPC_STL	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
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1:
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#endif /* CONFIG_SMP */
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	/* Hack: if we get an altivec unavailable trap with VRSAVE
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	 * set to all zeros, we assume this is a broken application
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	 * that fails to set it properly, and thus we switch it to
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	 * all 1's
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	 */
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	mfspr	r4,SPRN_VRSAVE
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	cmpwi	0,r4,0
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	bne+	1f
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	li	r4,-1
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	mtspr	SPRN_VRSAVE,r4
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1:
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	/* enable use of VMX after return */
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#ifdef CONFIG_PPC32
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	mfspr	r5,SPRN_SPRG_THREAD		/* current task's THREAD (phys) */
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	oris	r9,r9,MSR_VEC@h
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#else
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	ld	r4,PACACURRENT(r13)
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	addi	r5,r4,THREAD		/* Get THREAD */
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	oris	r12,r12,MSR_VEC@h
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	std	r12,_MSR(r1)
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#endif
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	li	r4,1
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	li	r10,THREAD_VSCR
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	stw	r4,THREAD_USED_VR(r5)
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	lvx	vr0,r10,r5
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	mtvscr	vr0
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	REST_32VRS(0,r4,r5)
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#ifndef CONFIG_SMP
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	/* Update last_task_used_altivec to 'current' */
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	subi	r4,r5,THREAD		/* Back to 'current' */
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	fromreal(r4)
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	PPC_STL	r4,ADDROFF(last_task_used_altivec)(r3)
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#endif /* CONFIG_SMP */
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	/* restore registers and return */
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	blr
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/*
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 * giveup_altivec(tsk)
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 * Disable VMX for the task given as the argument,
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 * and save the vector registers in its thread_struct.
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 * Enables the VMX for use in the kernel on return.
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 */
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_GLOBAL(giveup_altivec)
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	mfmsr	r5
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	oris	r5,r5,MSR_VEC@h
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	SYNC
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	MTMSRD(r5)			/* enable use of VMX now */
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	isync
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	PPC_LCMPI	0,r3,0
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	beqlr-				/* if no previous owner, done */
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	addi	r3,r3,THREAD		/* want THREAD of task */
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	PPC_LL	r5,PT_REGS(r3)
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	PPC_LCMPI	0,r5,0
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	SAVE_32VRS(0,r4,r3)
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	mfvscr	vr0
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	li	r4,THREAD_VSCR
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	stvx	vr0,r4,r3
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	beq	1f
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	PPC_LL	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
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#ifdef CONFIG_VSX
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BEGIN_FTR_SECTION
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	lis	r3,(MSR_VEC|MSR_VSX)@h
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FTR_SECTION_ELSE
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	lis	r3,MSR_VEC@h
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ALT_FTR_SECTION_END_IFSET(CPU_FTR_VSX)
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#else
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	lis	r3,MSR_VEC@h
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#endif
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	andc	r4,r4,r3		/* disable FP for previous task */
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	PPC_STL	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
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1:
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#ifndef CONFIG_SMP
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	li	r5,0
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	LOAD_REG_ADDRBASE(r4,last_task_used_altivec)
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	PPC_STL	r5,ADDROFF(last_task_used_altivec)(r4)
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#endif /* CONFIG_SMP */
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	blr
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#ifdef CONFIG_VSX
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#ifdef CONFIG_PPC32
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#error This asm code isn't ready for 32-bit kernels
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#endif
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/*
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 * load_up_vsx(unused, unused, tsk)
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 * Disable VSX for the task which had it previously,
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 * and save its vector registers in its thread_struct.
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 * Reuse the fp and vsx saves, but first check to see if they have
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 * been saved already.
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 */
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_GLOBAL(load_up_vsx)
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/* Load FP and VSX registers if they haven't been done yet */
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	andi.	r5,r12,MSR_FP
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	beql+	load_up_fpu		/* skip if already loaded */
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	andis.	r5,r12,MSR_VEC@h
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	beql+	load_up_altivec		/* skip if already loaded */
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#ifndef CONFIG_SMP
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	ld	r3,last_task_used_vsx@got(r2)
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	ld	r4,0(r3)
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	cmpdi	0,r4,0
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	beq	1f
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	/* Disable VSX for last_task_used_vsx */
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	addi	r4,r4,THREAD
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	ld	r5,PT_REGS(r4)
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	ld	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
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	lis	r6,MSR_VSX@h
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	andc	r6,r4,r6
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	std	r6,_MSR-STACK_FRAME_OVERHEAD(r5)
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1:
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#endif /* CONFIG_SMP */
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	ld	r4,PACACURRENT(r13)
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	addi	r4,r4,THREAD		/* Get THREAD */
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	li	r6,1
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	stw	r6,THREAD_USED_VSR(r4) /* ... also set thread used vsr */
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	/* enable use of VSX after return */
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	oris	r12,r12,MSR_VSX@h
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	std	r12,_MSR(r1)
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#ifndef CONFIG_SMP
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	/* Update last_task_used_vsx to 'current' */
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	ld	r4,PACACURRENT(r13)
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	std	r4,0(r3)
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#endif /* CONFIG_SMP */
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	b	fast_exception_return
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/*
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 * __giveup_vsx(tsk)
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 * Disable VSX for the task given as the argument.
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 * Does NOT save vsx registers.
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 * Enables the VSX for use in the kernel on return.
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 */
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_GLOBAL(__giveup_vsx)
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	mfmsr	r5
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	oris	r5,r5,MSR_VSX@h
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	mtmsrd	r5			/* enable use of VSX now */
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	isync
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	cmpdi	0,r3,0
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	beqlr-				/* if no previous owner, done */
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	addi	r3,r3,THREAD		/* want THREAD of task */
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	ld	r5,PT_REGS(r3)
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	cmpdi	0,r5,0
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	beq	1f
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	ld	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
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	lis	r3,MSR_VSX@h
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	andc	r4,r4,r3		/* disable VSX for previous task */
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	std	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
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1:
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#ifndef CONFIG_SMP
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	li	r5,0
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	ld	r4,last_task_used_vsx@got(r2)
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	std	r5,0(r4)
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#endif /* CONFIG_SMP */
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	blr
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#endif /* CONFIG_VSX */
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/*
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 * The routines below are in assembler so we can closely control the
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 * usage of floating-point registers.  These routines must be called
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 * with preempt disabled.
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 */
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#ifdef CONFIG_PPC32
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	.data
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fpzero:
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	.long	0
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fpone:
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	.long	0x3f800000	/* 1.0 in single-precision FP */
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fphalf:
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	.long	0x3f000000	/* 0.5 in single-precision FP */
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#define LDCONST(fr, name)	\
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	lis	r11,name@ha;	\
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	lfs	fr,name@l(r11)
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#else
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	.section ".toc","aw"
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fpzero:
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	.tc	FD_0_0[TC],0
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fpone:
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	.tc	FD_3ff00000_0[TC],0x3ff0000000000000	/* 1.0 */
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fphalf:
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	.tc	FD_3fe00000_0[TC],0x3fe0000000000000	/* 0.5 */
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#define LDCONST(fr, name)	\
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	lfd	fr,name@toc(r2)
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#endif
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	.text
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/*
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 * Internal routine to enable floating point and set FPSCR to 0.
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 * Don't call it from C; it doesn't use the normal calling convention.
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 */
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fpenable:
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#ifdef CONFIG_PPC32
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	stwu	r1,-64(r1)
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#else
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	stdu	r1,-64(r1)
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#endif
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	mfmsr	r10
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	ori	r11,r10,MSR_FP
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	mtmsr	r11
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	isync
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	stfd	fr0,24(r1)
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	stfd	fr1,16(r1)
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	stfd	fr31,8(r1)
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	LDCONST(fr1, fpzero)
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	mffs	fr31
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	MTFSF_L(fr1)
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	blr
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fpdisable:
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	mtlr	r12
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	MTFSF_L(fr31)
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	lfd	fr31,8(r1)
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	lfd	fr1,16(r1)
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	lfd	fr0,24(r1)
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	mtmsr	r10
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	isync
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	addi	r1,r1,64
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	blr
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/*
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 * Vector add, floating point.
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 */
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_GLOBAL(vaddfp)
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	mflr	r12
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	bl	fpenable
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	li	r0,4
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	mtctr	r0
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	li	r6,0
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1:	lfsx	fr0,r4,r6
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	lfsx	fr1,r5,r6
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	fadds	fr0,fr0,fr1
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	stfsx	fr0,r3,r6
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	addi	r6,r6,4
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	bdnz	1b
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	b	fpdisable
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/*
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 * Vector subtract, floating point.
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 */
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_GLOBAL(vsubfp)
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	mflr	r12
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	bl	fpenable
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	li	r0,4
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	mtctr	r0
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	li	r6,0
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1:	lfsx	fr0,r4,r6
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	lfsx	fr1,r5,r6
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	fsubs	fr0,fr0,fr1
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	stfsx	fr0,r3,r6
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	addi	r6,r6,4
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	bdnz	1b
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	b	fpdisable
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/*
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 * Vector multiply and add, floating point.
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 */
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_GLOBAL(vmaddfp)
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	mflr	r12
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	bl	fpenable
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	stfd	fr2,32(r1)
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	li	r0,4
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	mtctr	r0
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	li	r7,0
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1:	lfsx	fr0,r4,r7
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	lfsx	fr1,r5,r7
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	lfsx	fr2,r6,r7
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	fmadds	fr0,fr0,fr2,fr1
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	stfsx	fr0,r3,r7
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	addi	r7,r7,4
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	bdnz	1b
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	lfd	fr2,32(r1)
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	b	fpdisable
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/*
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 * Vector negative multiply and subtract, floating point.
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 */
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_GLOBAL(vnmsubfp)
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	mflr	r12
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	bl	fpenable
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	stfd	fr2,32(r1)
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	li	r0,4
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	mtctr	r0
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	li	r7,0
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1:	lfsx	fr0,r4,r7
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	lfsx	fr1,r5,r7
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	lfsx	fr2,r6,r7
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	fnmsubs	fr0,fr0,fr2,fr1
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	stfsx	fr0,r3,r7
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	addi	r7,r7,4
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	bdnz	1b
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	lfd	fr2,32(r1)
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	b	fpdisable
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/*
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 * Vector reciprocal estimate.  We just compute 1.0/x.
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 * r3 -> destination, r4 -> source.
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 */
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_GLOBAL(vrefp)
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	mflr	r12
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	bl	fpenable
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	li	r0,4
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	LDCONST(fr1, fpone)
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	mtctr	r0
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	li	r6,0
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1:	lfsx	fr0,r4,r6
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	fdivs	fr0,fr1,fr0
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	stfsx	fr0,r3,r6
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	addi	r6,r6,4
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	bdnz	1b
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	b	fpdisable
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/*
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 * Vector reciprocal square-root estimate, floating point.
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 * We use the frsqrte instruction for the initial estimate followed
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 * by 2 iterations of Newton-Raphson to get sufficient accuracy.
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 * r3 -> destination, r4 -> source.
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 */
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_GLOBAL(vrsqrtefp)
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	mflr	r12
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	bl	fpenable
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	stfd	fr2,32(r1)
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	stfd	fr3,40(r1)
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	stfd	fr4,48(r1)
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	stfd	fr5,56(r1)
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	li	r0,4
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	LDCONST(fr4, fpone)
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	LDCONST(fr5, fphalf)
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	mtctr	r0
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	li	r6,0
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1:	lfsx	fr0,r4,r6
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	frsqrte	fr1,fr0		/* r = frsqrte(s) */
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	fmuls	fr3,fr1,fr0	/* r * s */
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	fmuls	fr2,fr1,fr5	/* r * 0.5 */
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	fnmsubs	fr3,fr1,fr3,fr4	/* 1 - s * r * r */
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	fmadds	fr1,fr2,fr3,fr1	/* r = r + 0.5 * r * (1 - s * r * r) */
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	fmuls	fr3,fr1,fr0	/* r * s */
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	fmuls	fr2,fr1,fr5	/* r * 0.5 */
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	fnmsubs	fr3,fr1,fr3,fr4	/* 1 - s * r * r */
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	fmadds	fr1,fr2,fr3,fr1	/* r = r + 0.5 * r * (1 - s * r * r) */
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	stfsx	fr1,r3,r6
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	addi	r6,r6,4
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	bdnz	1b
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	lfd	fr5,56(r1)
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	lfd	fr4,48(r1)
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	lfd	fr3,40(r1)
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	lfd	fr2,32(r1)
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	b	fpdisable
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