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/* ===-- divsi3.c - Implement __divsi3 -------------------------------------=== |
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* |
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* The LLVM Compiler Infrastructure |
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* |
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* This file is dual licensed under the MIT and the University of Illinois Open |
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* Source Licenses. See LICENSE.TXT for details. |
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* |
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* ===----------------------------------------------------------------------=== |
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* |
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* This file implements __divsi3 for the compiler_rt library. |
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* |
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* ===----------------------------------------------------------------------=== |
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*/ |
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#include "int_lib.h" |
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/* Returns: a / b */ |
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ARM_EABI_FNALIAS(idiv, divsi3) |
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COMPILER_RT_ABI si_int |
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__divsi3(si_int a, si_int b) |
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{ |
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const int bits_in_word_m1 = (int)(sizeof(si_int) * CHAR_BIT) - 1; |
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si_int s_a = a >> bits_in_word_m1; /* s_a = a < 0 ? -1 : 0 */ |
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si_int s_b = b >> bits_in_word_m1; /* s_b = b < 0 ? -1 : 0 */ |
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a = (a ^ s_a) - s_a; /* negate if s_a == -1 */ |
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b = (b ^ s_b) - s_b; /* negate if s_b == -1 */ |
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s_a ^= s_b; /* sign of quotient */ |
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/* |
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* On CPUs without unsigned hardware division support, |
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* this calls __udivsi3 (notice the cast to su_int). |
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* On CPUs with unsigned hardware division support, |
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* this uses the unsigned division instruction. |
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*/ |
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return ((su_int)a/(su_int)b ^ s_a) - s_a; /* negate if s_a == -1 */ |
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} |