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e2b36d5917
"Reconciling" in terms of interrupt handling, is to bring the soft irq
mask state in to synch with the hardware, after an interrupt causes
MSR[EE] to be cleared (while the soft mask may be enabled, and hard
irqs not marked disabled).
General kernel code should not be called while unreconciled, because
local_irq_disable, etc. manipulations can cause surprising irq traces,
and it's fragile because the soft irq code does not really expect to
be called in this situation.
When exiting from an interrupt, MSR[EE] is cleared to prevent races,
but soft irq state is enabled for the returned-to context, so this is
now an unreconciled state. restore_math is called in this state, and
that can be ftraced, and the ftrace subsystem disables local irqs.
Mark restore_math and its callees as notrace. Restore a sanity check
in the soft irq code that had to be disabled for this case, by commit
4da1f79227 ("powerpc/64: Disable irq restore warning for now").
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
332 lines
6.7 KiB
ArmAsm
332 lines
6.7 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
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#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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#include <asm/ptrace.h>
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#include <asm/export.h>
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#include <asm/asm-compat.h>
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/*
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* Load state from memory into VMX registers including VSCR.
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* Assumes the caller has enabled VMX in the MSR.
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*/
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_GLOBAL(load_vr_state)
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li r4,VRSTATE_VSCR
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lvx v0,r4,r3
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mtvscr v0
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REST_32VRS(0,r4,r3)
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blr
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EXPORT_SYMBOL(load_vr_state)
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_ASM_NOKPROBE_SYMBOL(load_vr_state); /* used by restore_math */
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/*
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* Store VMX state into memory, including VSCR.
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* Assumes the caller has enabled VMX in the MSR.
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*/
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_GLOBAL(store_vr_state)
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SAVE_32VRS(0, r4, r3)
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mfvscr v0
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li r4, VRSTATE_VSCR
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stvx v0, r4, r3
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blr
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EXPORT_SYMBOL(store_vr_state)
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/*
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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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* Note that on 32-bit this can only use registers that will be
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* restored by fast_exception_return, i.e. r3 - r6, r10 and r11.
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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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* While userspace in general ignores VRSAVE, glibc uses it as a boolean
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* to optimise userspace context save/restore. Whenever we take an
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* altivec unavailable exception we must set VRSAVE to something non
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* zero. Set it to all 1s. See also the programming note in the ISA.
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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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/* Don't care if r4 overflows, this is desired behaviour */
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lbz r4,THREAD_LOAD_VEC(r5)
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addi r4,r4,1
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stb r4,THREAD_LOAD_VEC(r5)
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addi r6,r5,THREAD_VRSTATE
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li r4,1
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li r10,VRSTATE_VSCR
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stw r4,THREAD_USED_VR(r5)
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lvx v0,r10,r6
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mtvscr v0
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REST_32VRS(0,r4,r6)
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/* restore registers and return */
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blr
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/*
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* save_altivec(tsk)
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* Save the vector registers to its thread_struct
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*/
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_GLOBAL(save_altivec)
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addi r3,r3,THREAD /* want THREAD of task */
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PPC_LL r7,THREAD_VRSAVEAREA(r3)
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PPC_LL r5,PT_REGS(r3)
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PPC_LCMPI 0,r7,0
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bne 2f
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addi r7,r3,THREAD_VRSTATE
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2: SAVE_32VRS(0,r4,r7)
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mfvscr v0
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li r4,VRSTATE_VSCR
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stvx v0,r4,r7
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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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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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b fast_exception_return
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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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