177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao/*===-- mulvdi3.c - Implement __mulvdi3 -----------------------------------=== 277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * 377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * The LLVM Compiler Infrastructure 477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * 577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * This file is distributed under the University of Illinois Open Source 677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * License. See LICENSE.TXT for details. 777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * 877ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * ===----------------------------------------------------------------------=== 977ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * 1077ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * This file implements __mulvdi3 for the compiler_rt library. 1177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * 1277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao * ===----------------------------------------------------------------------=== 1377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao */ 1477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 1577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao#include "int_lib.h" 1677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao#include <stdlib.h> 1777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 1877ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao/* Returns: a * b */ 1977ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 2077ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao/* Effects: aborts if a * b overflows */ 2177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao 2277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liaodi_int 2377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao__mulvdi3(di_int a, di_int b) 2477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao{ 2577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao const int N = (int)(sizeof(di_int) * CHAR_BIT); 2677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao const di_int MIN = (di_int)1 << (N-1); 2777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao const di_int MAX = ~MIN; 2877ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao if (a == MIN) 2977ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao { 3077ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao if (b == 0 || b == 1) 3177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao return a * b; 3277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao abort(); 3377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao } 3477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao if (b == MIN) 3577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao { 3677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao if (a == 0 || a == 1) 3777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao return a * b; 3877ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao abort(); 3977ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao } 4077ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao di_int sa = a >> (N - 1); 4177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao di_int abs_a = (a ^ sa) - sa; 4277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao di_int sb = b >> (N - 1); 4377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao di_int abs_b = (b ^ sb) - sb; 4477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao if (abs_a < 2 || abs_b < 2) 4577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao return a * b; 4677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao if (sa == sb) 4777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao { 4877ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao if (abs_a > MAX / abs_b) 4977ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao abort(); 5077ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao } 5177ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao else 5277ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao { 5377ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao if (abs_a > MIN / -abs_b) 5477ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao abort(); 5577ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao } 5677ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao return a * b; 5777ed6142daed1e068fbda64405d0de9845e40e1Shih-wei Liao} 58