forked from OSchip/llvm-project
35 lines
1.1 KiB
C
35 lines
1.1 KiB
C
//===-- divti3.c - Implement __divti3 -------------------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements __divti3 for the compiler_rt library.
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//
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//===----------------------------------------------------------------------===//
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#if __x86_64
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#include "int_lib.h"
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tu_int __udivmodti4(tu_int a, tu_int b, tu_int* rem);
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// Returns: a / b
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ti_int
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__divti3(ti_int a, ti_int b)
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{
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const int bits_in_tword_m1 = (int)(sizeof(ti_int) * CHAR_BIT) - 1;
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ti_int s_a = a >> bits_in_tword_m1; // s_a = a < 0 ? -1 : 0
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ti_int s_b = b >> bits_in_tword_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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return (__udivmodti4(a, b, (tu_int*)0) ^ s_a) - s_a; // negate if s_a == -1
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}
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#endif
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