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linux/arch/powerpc/math-emu/math_efp.c
Liu Yu 6a800f36ac powerpc: Add SPE/EFP math emulation for E500v1/v2 processors. 
This patch add the handlers of SPE/EFP exceptions.
The code is used to emulate float point arithmetic,
when MSR(SPE) is enabled and receive EFP data interrupt or EFP round interrupt.

This patch has no conflict with or dependence on FP math-emu.

The code has been tested by TestFloat.

Now the code doesn't support SPE/EFP instructions emulation
(it won't be called when receive program interrupt),
but it could be easily added.

Signed-off-by: Liu Yu <yu.liu@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2008-12-03 08:19:16 -06:00

721 lines
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/*
* arch/powerpc/math-emu/math_efp.c
*
* Copyright (C) 2006-2008 Freescale Semiconductor, Inc. All rights reserved.
*
* Author: Ebony Zhu, <ebony.zhu@freescale.com>
* Yu Liu, <yu.liu@freescale.com>
*
* Derived from arch/alpha/math-emu/math.c
* arch/powerpc/math-emu/math.c
*
* Description:
* This file is the exception handler to make E500 SPE instructions
* fully comply with IEEE-754 floating point standard.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/types.h>
#include <asm/uaccess.h>
#include <asm/reg.h>
#define FP_EX_BOOKE_E500_SPE
#include <asm/sfp-machine.h>
#include <math-emu/soft-fp.h>
#include <math-emu/single.h>
#include <math-emu/double.h>
#define EFAPU 0x4
#define VCT 0x4
#define SPFP 0x6
#define DPFP 0x7
#define EFSADD 0x2c0
#define EFSSUB 0x2c1
#define EFSABS 0x2c4
#define EFSNABS 0x2c5
#define EFSNEG 0x2c6
#define EFSMUL 0x2c8
#define EFSDIV 0x2c9
#define EFSCMPGT 0x2cc
#define EFSCMPLT 0x2cd
#define EFSCMPEQ 0x2ce
#define EFSCFD 0x2cf
#define EFSCFSI 0x2d1
#define EFSCTUI 0x2d4
#define EFSCTSI 0x2d5
#define EFSCTUF 0x2d6
#define EFSCTSF 0x2d7
#define EFSCTUIZ 0x2d8
#define EFSCTSIZ 0x2da
#define EVFSADD 0x280
#define EVFSSUB 0x281
#define EVFSABS 0x284
#define EVFSNABS 0x285
#define EVFSNEG 0x286
#define EVFSMUL 0x288
#define EVFSDIV 0x289
#define EVFSCMPGT 0x28c
#define EVFSCMPLT 0x28d
#define EVFSCMPEQ 0x28e
#define EVFSCTUI 0x294
#define EVFSCTSI 0x295
#define EVFSCTUF 0x296
#define EVFSCTSF 0x297
#define EVFSCTUIZ 0x298
#define EVFSCTSIZ 0x29a
#define EFDADD 0x2e0
#define EFDSUB 0x2e1
#define EFDABS 0x2e4
#define EFDNABS 0x2e5
#define EFDNEG 0x2e6
#define EFDMUL 0x2e8
#define EFDDIV 0x2e9
#define EFDCTUIDZ 0x2ea
#define EFDCTSIDZ 0x2eb
#define EFDCMPGT 0x2ec
#define EFDCMPLT 0x2ed
#define EFDCMPEQ 0x2ee
#define EFDCFS 0x2ef
#define EFDCTUI 0x2f4
#define EFDCTSI 0x2f5
#define EFDCTUF 0x2f6
#define EFDCTSF 0x2f7
#define EFDCTUIZ 0x2f8
#define EFDCTSIZ 0x2fa
#define AB 2
#define XA 3
#define XB 4
#define XCR 5
#define NOTYPE 0
#define SIGN_BIT_S (1UL << 31)
#define SIGN_BIT_D (1ULL << 63)
#define FP_EX_MASK (FP_EX_INEXACT | FP_EX_INVALID | FP_EX_DIVZERO | \
FP_EX_UNDERFLOW | FP_EX_OVERFLOW)
union dw_union {
u64 dp[1];
u32 wp[2];
};
static unsigned long insn_type(unsigned long speinsn)
{
unsigned long ret = NOTYPE;
switch (speinsn & 0x7ff) {
case EFSABS: ret = XA; break;
case EFSADD: ret = AB; break;
case EFSCFD: ret = XB; break;
case EFSCMPEQ: ret = XCR; break;
case EFSCMPGT: ret = XCR; break;
case EFSCMPLT: ret = XCR; break;
case EFSCTSF: ret = XB; break;
case EFSCTSI: ret = XB; break;
case EFSCTSIZ: ret = XB; break;
case EFSCTUF: ret = XB; break;
case EFSCTUI: ret = XB; break;
case EFSCTUIZ: ret = XB; break;
case EFSDIV: ret = AB; break;
case EFSMUL: ret = AB; break;
case EFSNABS: ret = XA; break;
case EFSNEG: ret = XA; break;
case EFSSUB: ret = AB; break;
case EFSCFSI: ret = XB; break;
case EVFSABS: ret = XA; break;
case EVFSADD: ret = AB; break;
case EVFSCMPEQ: ret = XCR; break;
case EVFSCMPGT: ret = XCR; break;
case EVFSCMPLT: ret = XCR; break;
case EVFSCTSF: ret = XB; break;
case EVFSCTSI: ret = XB; break;
case EVFSCTSIZ: ret = XB; break;
case EVFSCTUF: ret = XB; break;
case EVFSCTUI: ret = XB; break;
case EVFSCTUIZ: ret = XB; break;
case EVFSDIV: ret = AB; break;
case EVFSMUL: ret = AB; break;
case EVFSNABS: ret = XA; break;
case EVFSNEG: ret = XA; break;
case EVFSSUB: ret = AB; break;
case EFDABS: ret = XA; break;
case EFDADD: ret = AB; break;
case EFDCFS: ret = XB; break;
case EFDCMPEQ: ret = XCR; break;
case EFDCMPGT: ret = XCR; break;
case EFDCMPLT: ret = XCR; break;
case EFDCTSF: ret = XB; break;
case EFDCTSI: ret = XB; break;
case EFDCTSIDZ: ret = XB; break;
case EFDCTSIZ: ret = XB; break;
case EFDCTUF: ret = XB; break;
case EFDCTUI: ret = XB; break;
case EFDCTUIDZ: ret = XB; break;
case EFDCTUIZ: ret = XB; break;
case EFDDIV: ret = AB; break;
case EFDMUL: ret = AB; break;
case EFDNABS: ret = XA; break;
case EFDNEG: ret = XA; break;
case EFDSUB: ret = AB; break;
default:
printk(KERN_ERR "\nOoops! SPE instruction no type found.");
printk(KERN_ERR "\ninst code: %08lx\n", speinsn);
}
return ret;
}
int do_spe_mathemu(struct pt_regs *regs)
{
FP_DECL_EX;
int IR, cmp;
unsigned long type, func, fc, fa, fb, src, speinsn;
union dw_union vc, va, vb;
if (get_user(speinsn, (unsigned int __user *) regs->nip))
return -EFAULT;
if ((speinsn >> 26) != EFAPU)
return -EINVAL; /* not an spe instruction */
type = insn_type(speinsn);
if (type == NOTYPE)
return -ENOSYS;
func = speinsn & 0x7ff;
fc = (speinsn >> 21) & 0x1f;
fa = (speinsn >> 16) & 0x1f;
fb = (speinsn >> 11) & 0x1f;
src = (speinsn >> 5) & 0x7;
vc.wp[0] = current->thread.evr[fc];
vc.wp[1] = regs->gpr[fc];
va.wp[0] = current->thread.evr[fa];
va.wp[1] = regs->gpr[fa];
vb.wp[0] = current->thread.evr[fb];
vb.wp[1] = regs->gpr[fb];
__FPU_FPSCR = mfspr(SPRN_SPEFSCR);
#ifdef DEBUG
printk("speinsn:%08lx spefscr:%08lx\n", speinsn, __FPU_FPSCR);
printk("vc: %08x %08x\n", vc.wp[0], vc.wp[1]);
printk("va: %08x %08x\n", va.wp[0], va.wp[1]);
printk("vb: %08x %08x\n", vb.wp[0], vb.wp[1]);
#endif
switch (src) {
case SPFP: {
FP_DECL_S(SA); FP_DECL_S(SB); FP_DECL_S(SR);
switch (type) {
case AB:
case XCR:
FP_UNPACK_SP(SA, va.wp + 1);
case XB:
FP_UNPACK_SP(SB, vb.wp + 1);
break;
case XA:
FP_UNPACK_SP(SA, va.wp + 1);
break;
}
#ifdef DEBUG
printk("SA: %ld %08lx %ld (%ld)\n", SA_s, SA_f, SA_e, SA_c);
printk("SB: %ld %08lx %ld (%ld)\n", SB_s, SB_f, SB_e, SB_c);
#endif
switch (func) {
case EFSABS:
vc.wp[1] = va.wp[1] & ~SIGN_BIT_S;
goto update_regs;
case EFSNABS:
vc.wp[1] = va.wp[1] | SIGN_BIT_S;
goto update_regs;
case EFSNEG:
vc.wp[1] = va.wp[1] ^ SIGN_BIT_S;
goto update_regs;
case EFSADD:
FP_ADD_S(SR, SA, SB);
goto pack_s;
case EFSSUB:
FP_SUB_S(SR, SA, SB);
goto pack_s;
case EFSMUL:
FP_MUL_S(SR, SA, SB);
goto pack_s;
case EFSDIV:
FP_DIV_S(SR, SA, SB);
goto pack_s;
case EFSCMPEQ:
cmp = 0;
goto cmp_s;
case EFSCMPGT:
cmp = 1;
goto cmp_s;
case EFSCMPLT:
cmp = -1;
goto cmp_s;
case EFSCTSF:
case EFSCTUF:
if (!((vb.wp[1] >> 23) == 0xff && ((vb.wp[1] & 0x7fffff) > 0))) {
/* NaN */
if (((vb.wp[1] >> 23) & 0xff) == 0) {
/* denorm */
vc.wp[1] = 0x0;
} else if ((vb.wp[1] >> 31) == 0) {
/* positive normal */
vc.wp[1] = (func == EFSCTSF) ?
0x7fffffff : 0xffffffff;
} else { /* negative normal */
vc.wp[1] = (func == EFSCTSF) ?
0x80000000 : 0x0;
}
} else { /* rB is NaN */
vc.wp[1] = 0x0;
}
goto update_regs;
case EFSCFD: {
FP_DECL_D(DB);
FP_CLEAR_EXCEPTIONS;
FP_UNPACK_DP(DB, vb.dp);
#ifdef DEBUG
printk("DB: %ld %08lx %08lx %ld (%ld)\n",
DB_s, DB_f1, DB_f0, DB_e, DB_c);
#endif
FP_CONV(S, D, 1, 2, SR, DB);
goto pack_s;
}
case EFSCTSI:
case EFSCTSIZ:
case EFSCTUI:
case EFSCTUIZ:
if (func & 0x4) {
_FP_ROUND(1, SB);
} else {
_FP_ROUND_ZERO(1, SB);
}
FP_TO_INT_S(vc.wp[1], SB, 32, ((func & 0x3) != 0));
goto update_regs;
default:
goto illegal;
}
break;
pack_s:
#ifdef DEBUG
printk("SR: %ld %08lx %ld (%ld)\n", SR_s, SR_f, SR_e, SR_c);
#endif
FP_PACK_SP(vc.wp + 1, SR);
goto update_regs;
cmp_s:
FP_CMP_S(IR, SA, SB, 3);
if (IR == 3 && (FP_ISSIGNAN_S(SA) || FP_ISSIGNAN_S(SB)))
FP_SET_EXCEPTION(FP_EX_INVALID);
if (IR == cmp) {
IR = 0x4;
} else {
IR = 0;
}
goto update_ccr;
}
case DPFP: {
FP_DECL_D(DA); FP_DECL_D(DB); FP_DECL_D(DR);
switch (type) {
case AB:
case XCR:
FP_UNPACK_DP(DA, va.dp);
case XB:
FP_UNPACK_DP(DB, vb.dp);
break;
case XA:
FP_UNPACK_DP(DA, va.dp);
break;
}
#ifdef DEBUG
printk("DA: %ld %08lx %08lx %ld (%ld)\n",
DA_s, DA_f1, DA_f0, DA_e, DA_c);
printk("DB: %ld %08lx %08lx %ld (%ld)\n",
DB_s, DB_f1, DB_f0, DB_e, DB_c);
#endif
switch (func) {
case EFDABS:
vc.dp[0] = va.dp[0] & ~SIGN_BIT_D;
goto update_regs;
case EFDNABS:
vc.dp[0] = va.dp[0] | SIGN_BIT_D;
goto update_regs;
case EFDNEG:
vc.dp[0] = va.dp[0] ^ SIGN_BIT_D;
goto update_regs;
case EFDADD:
FP_ADD_D(DR, DA, DB);
goto pack_d;
case EFDSUB:
FP_SUB_D(DR, DA, DB);
goto pack_d;
case EFDMUL:
FP_MUL_D(DR, DA, DB);
goto pack_d;
case EFDDIV:
FP_DIV_D(DR, DA, DB);
goto pack_d;
case EFDCMPEQ:
cmp = 0;
goto cmp_d;
case EFDCMPGT:
cmp = 1;
goto cmp_d;
case EFDCMPLT:
cmp = -1;
goto cmp_d;
case EFDCTSF:
case EFDCTUF:
if (!((vb.wp[0] >> 20) == 0x7ff &&
((vb.wp[0] & 0xfffff) > 0 || (vb.wp[1] > 0)))) {
/* not a NaN */
if (((vb.wp[0] >> 20) & 0x7ff) == 0) {
/* denorm */
vc.wp[1] = 0x0;
} else if ((vb.wp[0] >> 31) == 0) {
/* positive normal */
vc.wp[1] = (func == EFDCTSF) ?
0x7fffffff : 0xffffffff;
} else { /* negative normal */
vc.wp[1] = (func == EFDCTSF) ?
0x80000000 : 0x0;
}
} else { /* NaN */
vc.wp[1] = 0x0;
}
goto update_regs;
case EFDCFS: {
FP_DECL_S(SB);
FP_CLEAR_EXCEPTIONS;
FP_UNPACK_SP(SB, vb.wp + 1);
#ifdef DEBUG
printk("SB: %ld %08lx %ld (%ld)\n",
SB_s, SB_f, SB_e, SB_c);
#endif
FP_CONV(D, S, 2, 1, DR, SB);
goto pack_d;
}
case EFDCTUIDZ:
case EFDCTSIDZ:
_FP_ROUND_ZERO(2, DB);
FP_TO_INT_D(vc.dp[0], DB, 64, ((func & 0x1) == 0));
goto update_regs;
case EFDCTUI:
case EFDCTSI:
case EFDCTUIZ:
case EFDCTSIZ:
if (func & 0x4) {
_FP_ROUND(2, DB);
} else {
_FP_ROUND_ZERO(2, DB);
}
FP_TO_INT_D(vc.wp[1], DB, 32, ((func & 0x3) != 0));
goto update_regs;
default:
goto illegal;
}
break;
pack_d:
#ifdef DEBUG
printk("DR: %ld %08lx %08lx %ld (%ld)\n",
DR_s, DR_f1, DR_f0, DR_e, DR_c);
#endif
FP_PACK_DP(vc.dp, DR);
goto update_regs;
cmp_d:
FP_CMP_D(IR, DA, DB, 3);
if (IR == 3 && (FP_ISSIGNAN_D(DA) || FP_ISSIGNAN_D(DB)))
FP_SET_EXCEPTION(FP_EX_INVALID);
if (IR == cmp) {
IR = 0x4;
} else {
IR = 0;
}
goto update_ccr;
}
case VCT: {
FP_DECL_S(SA0); FP_DECL_S(SB0); FP_DECL_S(SR0);
FP_DECL_S(SA1); FP_DECL_S(SB1); FP_DECL_S(SR1);
int IR0, IR1;
switch (type) {
case AB:
case XCR:
FP_UNPACK_SP(SA0, va.wp);
FP_UNPACK_SP(SA1, va.wp + 1);
case XB:
FP_UNPACK_SP(SB0, vb.wp);
FP_UNPACK_SP(SB1, vb.wp + 1);
break;
case XA:
FP_UNPACK_SP(SA0, va.wp);
FP_UNPACK_SP(SA1, va.wp + 1);
break;
}
#ifdef DEBUG
printk("SA0: %ld %08lx %ld (%ld)\n", SA0_s, SA0_f, SA0_e, SA0_c);
printk("SA1: %ld %08lx %ld (%ld)\n", SA1_s, SA1_f, SA1_e, SA1_c);
printk("SB0: %ld %08lx %ld (%ld)\n", SB0_s, SB0_f, SB0_e, SB0_c);
printk("SB1: %ld %08lx %ld (%ld)\n", SB1_s, SB1_f, SB1_e, SB1_c);
#endif
switch (func) {
case EVFSABS:
vc.wp[0] = va.wp[0] & ~SIGN_BIT_S;
vc.wp[1] = va.wp[1] & ~SIGN_BIT_S;
goto update_regs;
case EVFSNABS:
vc.wp[0] = va.wp[0] | SIGN_BIT_S;
vc.wp[1] = va.wp[1] | SIGN_BIT_S;
goto update_regs;
case EVFSNEG:
vc.wp[0] = va.wp[0] ^ SIGN_BIT_S;
vc.wp[1] = va.wp[1] ^ SIGN_BIT_S;
goto update_regs;
case EVFSADD:
FP_ADD_S(SR0, SA0, SB0);
FP_ADD_S(SR1, SA1, SB1);
goto pack_vs;
case EVFSSUB:
FP_SUB_S(SR0, SA0, SB0);
FP_SUB_S(SR1, SA1, SB1);
goto pack_vs;
case EVFSMUL:
FP_MUL_S(SR0, SA0, SB0);
FP_MUL_S(SR1, SA1, SB1);
goto pack_vs;
case EVFSDIV:
FP_DIV_S(SR0, SA0, SB0);
FP_DIV_S(SR1, SA1, SB1);
goto pack_vs;
case EVFSCMPEQ:
cmp = 0;
goto cmp_vs;
case EVFSCMPGT:
cmp = 1;
goto cmp_vs;
case EVFSCMPLT:
cmp = -1;
goto cmp_vs;
case EVFSCTSF:
__asm__ __volatile__ ("mtspr 512, %4\n"
"efsctsf %0, %2\n"
"efsctsf %1, %3\n"
: "=r" (vc.wp[0]), "=r" (vc.wp[1])
: "r" (vb.wp[0]), "r" (vb.wp[1]), "r" (0));
goto update_regs;
case EVFSCTUF:
__asm__ __volatile__ ("mtspr 512, %4\n"
"efsctuf %0, %2\n"
"efsctuf %1, %3\n"
: "=r" (vc.wp[0]), "=r" (vc.wp[1])
: "r" (vb.wp[0]), "r" (vb.wp[1]), "r" (0));
goto update_regs;
case EVFSCTUI:
case EVFSCTSI:
case EVFSCTUIZ:
case EVFSCTSIZ:
if (func & 0x4) {
_FP_ROUND(1, SB0);
_FP_ROUND(1, SB1);
} else {
_FP_ROUND_ZERO(1, SB0);
_FP_ROUND_ZERO(1, SB1);
}
FP_TO_INT_S(vc.wp[0], SB0, 32, ((func & 0x3) != 0));
FP_TO_INT_S(vc.wp[1], SB1, 32, ((func & 0x3) != 0));
goto update_regs;
default:
goto illegal;
}
break;
pack_vs:
#ifdef DEBUG
printk("SR0: %ld %08lx %ld (%ld)\n", SR0_s, SR0_f, SR0_e, SR0_c);
printk("SR1: %ld %08lx %ld (%ld)\n", SR1_s, SR1_f, SR1_e, SR1_c);
#endif
FP_PACK_SP(vc.wp, SR0);
FP_PACK_SP(vc.wp + 1, SR1);
goto update_regs;
cmp_vs:
{
int ch, cl;
FP_CMP_S(IR0, SA0, SB0, 3);
FP_CMP_S(IR1, SA1, SB1, 3);
if (IR0 == 3 && (FP_ISSIGNAN_S(SA0) || FP_ISSIGNAN_S(SB0)))
FP_SET_EXCEPTION(FP_EX_INVALID);
if (IR1 == 3 && (FP_ISSIGNAN_S(SA1) || FP_ISSIGNAN_S(SB1)))
FP_SET_EXCEPTION(FP_EX_INVALID);
ch = (IR0 == cmp) ? 1 : 0;
cl = (IR1 == cmp) ? 1 : 0;
IR = (ch << 3) | (cl << 2) | ((ch | cl) << 1) |
((ch & cl) << 0);
goto update_ccr;
}
}
default:
return -EINVAL;
}
update_ccr:
regs->ccr &= ~(15 << ((7 - ((speinsn >> 23) & 0x7)) << 2));
regs->ccr |= (IR << ((7 - ((speinsn >> 23) & 0x7)) << 2));
update_regs:
__FPU_FPSCR &= ~FP_EX_MASK;
__FPU_FPSCR |= (FP_CUR_EXCEPTIONS & FP_EX_MASK);
mtspr(SPRN_SPEFSCR, __FPU_FPSCR);
current->thread.evr[fc] = vc.wp[0];
regs->gpr[fc] = vc.wp[1];
#ifdef DEBUG
printk("ccr = %08lx\n", regs->ccr);
printk("cur exceptions = %08x spefscr = %08lx\n",
FP_CUR_EXCEPTIONS, __FPU_FPSCR);
printk("vc: %08x %08x\n", vc.wp[0], vc.wp[1]);
printk("va: %08x %08x\n", va.wp[0], va.wp[1]);
printk("vb: %08x %08x\n", vb.wp[0], vb.wp[1]);
#endif
return 0;
illegal:
printk(KERN_ERR "\nOoops! IEEE-754 compliance handler encountered un-supported instruction.\ninst code: %08lx\n", speinsn);
return -ENOSYS;
}
int speround_handler(struct pt_regs *regs)
{
union dw_union fgpr;
int s_lo, s_hi;
unsigned long speinsn, type, fc;
if (get_user(speinsn, (unsigned int __user *) regs->nip))
return -EFAULT;
if ((speinsn >> 26) != 4)
return -EINVAL; /* not an spe instruction */
type = insn_type(speinsn & 0x7ff);
if (type == XCR) return -ENOSYS;
fc = (speinsn >> 21) & 0x1f;
s_lo = regs->gpr[fc] & SIGN_BIT_S;
s_hi = current->thread.evr[fc] & SIGN_BIT_S;
fgpr.wp[0] = current->thread.evr[fc];
fgpr.wp[1] = regs->gpr[fc];
__FPU_FPSCR = mfspr(SPRN_SPEFSCR);
switch ((speinsn >> 5) & 0x7) {
/* Since SPE instructions on E500 core can handle round to nearest
* and round toward zero with IEEE-754 complied, we just need
* to handle round toward +Inf and round toward -Inf by software.
*/
case SPFP:
if ((FP_ROUNDMODE) == FP_RND_PINF) {
if (!s_lo) fgpr.wp[1]++; /* Z > 0, choose Z1 */
} else { /* round to -Inf */
if (s_lo) fgpr.wp[1]++; /* Z < 0, choose Z2 */
}
break;
case DPFP:
if (FP_ROUNDMODE == FP_RND_PINF) {
if (!s_hi) fgpr.dp[0]++; /* Z > 0, choose Z1 */
} else { /* round to -Inf */
if (s_hi) fgpr.dp[0]++; /* Z < 0, choose Z2 */
}
break;
case VCT:
if (FP_ROUNDMODE == FP_RND_PINF) {
if (!s_lo) fgpr.wp[1]++; /* Z_low > 0, choose Z1 */
if (!s_hi) fgpr.wp[0]++; /* Z_high word > 0, choose Z1 */
} else { /* round to -Inf */
if (s_lo) fgpr.wp[1]++; /* Z_low < 0, choose Z2 */
if (s_hi) fgpr.wp[0]++; /* Z_high < 0, choose Z2 */
}
break;
default:
return -EINVAL;
}
current->thread.evr[fc] = fgpr.wp[0];
regs->gpr[fc] = fgpr.wp[1];
return 0;
}
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