/* MN10300 64-bit division * * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public Licence * as published by the Free Software Foundation; either version * 2 of the Licence, or (at your option) any later version. */ #ifndef _ASM_DIV64 #define _ASM_DIV64 #include <linux/types.h> extern void ____unhandled_size_in_do_div___(void); /* * Beginning with gcc 4.6, the MDR register is represented explicitly. We * must, therefore, at least explicitly clobber the register when we make * changes to it. The following assembly fragments *could* be rearranged in * order to leave the moves to/from the MDR register to the compiler, but the * gains would be minimal at best. */ #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6) # define CLOBBER_MDR_CC "mdr", "cc" #else # define CLOBBER_MDR_CC "cc" #endif /* * divide n by base, leaving the result in n and returning the remainder * - we can do this quite efficiently on the MN10300 by cascading the divides * through the MDR register */ #define do_div(n, base) \ ({ \ unsigned __rem = 0; \ if (sizeof(n) <= 4) { \ asm("mov %1,mdr \n" \ "divu %2,%0 \n" \ "mov mdr,%1 \n" \ : "+r"(n), "=d"(__rem) \ : "r"(base), "1"(__rem) \ : CLOBBER_MDR_CC \ ); \ } else if (sizeof(n) <= 8) { \ union { \ unsigned long long l; \ u32 w[2]; \ } __quot; \ __quot.l = n; \ asm("mov %0,mdr \n" /* MDR = 0 */ \ "divu %3,%1 \n" \ /* __quot.MSL = __div.MSL / base, */ \ /* MDR = MDR:__div.MSL % base */ \ "divu %3,%2 \n" \ /* __quot.LSL = MDR:__div.LSL / base, */ \ /* MDR = MDR:__div.LSL % base */ \ "mov mdr,%0 \n" \ : "=d"(__rem), "=r"(__quot.w[1]), "=r"(__quot.w[0]) \ : "r"(base), "0"(__rem), "1"(__quot.w[1]), \ "2"(__quot.w[0]) \ : CLOBBER_MDR_CC \ ); \ n = __quot.l; \ } else { \ ____unhandled_size_in_do_div___(); \ } \ __rem; \ }) /* * do an unsigned 32-bit multiply and divide with intermediate 64-bit product * so as not to lose accuracy * - we use the MDR register to hold the MSW of the product */ static inline __attribute__((const)) unsigned __muldiv64u(unsigned val, unsigned mult, unsigned div) { unsigned result; asm("mulu %2,%0 \n" /* MDR:val = val*mult */ "divu %3,%0 \n" /* val = MDR:val/div; * MDR = MDR:val%div */ : "=r"(result) : "0"(val), "ir"(mult), "r"(div) : CLOBBER_MDR_CC ); return result; } /* * do a signed 32-bit multiply and divide with intermediate 64-bit product so * as not to lose accuracy * - we use the MDR register to hold the MSW of the product */ static inline __attribute__((const)) signed __muldiv64s(signed val, signed mult, signed div) { signed result; asm("mul %2,%0 \n" /* MDR:val = val*mult */ "div %3,%0 \n" /* val = MDR:val/div; * MDR = MDR:val%div */ : "=r"(result) : "0"(val), "ir"(mult), "r"(div) : CLOBBER_MDR_CC ); return result; } #endif /* _ASM_DIV64 */
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asm-offsets.h | File | 35 B | 0644 |
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atomic.h | File | 4.02 KB | 0644 |
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bitops.h | File | 5.42 KB | 0644 |
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busctl-regs.h | File | 7.8 KB | 0644 |
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cache.h | File | 2.06 KB | 0644 |
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cacheflush.h | File | 7.6 KB | 0644 |
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checksum.h | File | 2.09 KB | 0644 |
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cmpxchg.h | File | 2.65 KB | 0644 |
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cpu-regs.h | File | 16.61 KB | 0644 |
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current.h | File | 922 B | 0644 |
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debugger.h | File | 1.2 KB | 0644 |
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delay.h | File | 597 B | 0644 |
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div64.h | File | 3.21 KB | 0644 |
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dma-mapping.h | File | 636 B | 0644 |
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dma.h | File | 3.09 KB | 0644 |
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dmactl-regs.h | File | 532 B | 0644 |
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elf.h | File | 4.49 KB | 0644 |
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emergency-restart.h | File | 43 B | 0644 |
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fpu.h | File | 3.57 KB | 0644 |
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frame.inc | File | 2.37 KB | 0644 |
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ftrace.h | File | 12 B | 0644 |
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futex.h | File | 31 B | 0644 |
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gdb-stub.h | File | 5.42 KB | 0644 |
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hardirq.h | File | 1.68 KB | 0644 |
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highmem.h | File | 3.01 KB | 0644 |
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hw_irq.h | File | 483 B | 0644 |
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intctl-regs.h | File | 2.26 KB | 0644 |
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io.h | File | 7.67 KB | 0644 |
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irq.h | File | 1.11 KB | 0644 |
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irq_regs.h | File | 751 B | 0644 |
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irqflags.h | File | 4.05 KB | 0644 |
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kgdb.h | File | 1.7 KB | 0644 |
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kmap_types.h | File | 160 B | 0644 |
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kprobes.h | File | 1.59 KB | 0644 |
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linkage.h | File | 593 B | 0644 |
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local.h | File | 31 B | 0644 |
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local64.h | File | 33 B | 0644 |
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mc146818rtc.h | File | 26 B | 0644 |
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mmu.h | File | 434 B | 0644 |
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mmu_context.h | File | 4.44 KB | 0644 |
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module.h | File | 677 B | 0644 |
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nmi.h | File | 500 B | 0644 |
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page.h | File | 3.63 KB | 0644 |
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page_offset.h | File | 302 B | 0644 |
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pci.h | File | 2.17 KB | 0644 |
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percpu.h | File | 32 B | 0644 |
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pgalloc.h | File | 1.49 KB | 0644 |
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pgtable.h | File | 15.68 KB | 0644 |
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pio-regs.h | File | 7.53 KB | 0644 |
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processor.h | File | 4.12 KB | 0644 |
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ptrace.h | File | 805 B | 0644 |
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reset-regs.h | File | 1.8 KB | 0644 |
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rtc.h | File | 692 B | 0644 |
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rwlock.h | File | 2.98 KB | 0644 |
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serial-regs.h | File | 8.85 KB | 0644 |
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serial.h | File | 1.02 KB | 0644 |
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setup.h | File | 574 B | 0644 |
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shmparam.h | File | 182 B | 0644 |
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signal.h | File | 888 B | 0644 |
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smp.h | File | 3.06 KB | 0644 |
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smsc911x.h | File | 27 B | 0644 |
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spinlock.h | File | 3.84 KB | 0644 |
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spinlock_types.h | File | 445 B | 0644 |
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string.h | File | 1.03 KB | 0644 |
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switch_to.h | File | 1.49 KB | 0644 |
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syscall.h | File | 2.38 KB | 0644 |
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thread_info.h | File | 4.36 KB | 0644 |
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tlb.h | File | 941 B | 0644 |
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tlbflush.h | File | 3.45 KB | 0644 |
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topology.h | File | 34 B | 0644 |
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types.h | File | 620 B | 0644 |
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uaccess.h | File | 7.78 KB | 0644 |
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ucontext.h | File | 673 B | 0644 |
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unaligned.h | File | 678 B | 0644 |
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unistd.h | File | 1.34 KB | 0644 |
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user.h | File | 1.91 KB | 0644 |
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xor.h | File | 29 B | 0644 |
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