1*0a6a1f1dSLionel Sambuc /*===-- mulvdi3.c - Implement __mulvdi3 -----------------------------------=== 2*0a6a1f1dSLionel Sambuc * 3*0a6a1f1dSLionel Sambuc * The LLVM Compiler Infrastructure 4*0a6a1f1dSLionel Sambuc * 5*0a6a1f1dSLionel Sambuc * This file is dual licensed under the MIT and the University of Illinois Open 6*0a6a1f1dSLionel Sambuc * Source Licenses. See LICENSE.TXT for details. 7*0a6a1f1dSLionel Sambuc * 8*0a6a1f1dSLionel Sambuc * ===----------------------------------------------------------------------=== 9*0a6a1f1dSLionel Sambuc * 10*0a6a1f1dSLionel Sambuc * This file implements __mulvdi3 for the compiler_rt library. 11*0a6a1f1dSLionel Sambuc * 12*0a6a1f1dSLionel Sambuc * ===----------------------------------------------------------------------=== 13*0a6a1f1dSLionel Sambuc */ 14*0a6a1f1dSLionel Sambuc 15*0a6a1f1dSLionel Sambuc #include "int_lib.h" 16*0a6a1f1dSLionel Sambuc 17*0a6a1f1dSLionel Sambuc /* Returns: a * b */ 18*0a6a1f1dSLionel Sambuc 19*0a6a1f1dSLionel Sambuc /* Effects: aborts if a * b overflows */ 20*0a6a1f1dSLionel Sambuc 21*0a6a1f1dSLionel Sambuc COMPILER_RT_ABI di_int __mulvdi3(di_int a,di_int b)22*0a6a1f1dSLionel Sambuc__mulvdi3(di_int a, di_int b) 23*0a6a1f1dSLionel Sambuc { 24*0a6a1f1dSLionel Sambuc const int N = (int)(sizeof(di_int) * CHAR_BIT); 25*0a6a1f1dSLionel Sambuc const di_int MIN = (di_int)1 << (N-1); 26*0a6a1f1dSLionel Sambuc const di_int MAX = ~MIN; 27*0a6a1f1dSLionel Sambuc if (a == MIN) 28*0a6a1f1dSLionel Sambuc { 29*0a6a1f1dSLionel Sambuc if (b == 0 || b == 1) 30*0a6a1f1dSLionel Sambuc return a * b; 31*0a6a1f1dSLionel Sambuc compilerrt_abort(); 32*0a6a1f1dSLionel Sambuc } 33*0a6a1f1dSLionel Sambuc if (b == MIN) 34*0a6a1f1dSLionel Sambuc { 35*0a6a1f1dSLionel Sambuc if (a == 0 || a == 1) 36*0a6a1f1dSLionel Sambuc return a * b; 37*0a6a1f1dSLionel Sambuc compilerrt_abort(); 38*0a6a1f1dSLionel Sambuc } 39*0a6a1f1dSLionel Sambuc di_int sa = a >> (N - 1); 40*0a6a1f1dSLionel Sambuc di_int abs_a = (a ^ sa) - sa; 41*0a6a1f1dSLionel Sambuc di_int sb = b >> (N - 1); 42*0a6a1f1dSLionel Sambuc di_int abs_b = (b ^ sb) - sb; 43*0a6a1f1dSLionel Sambuc if (abs_a < 2 || abs_b < 2) 44*0a6a1f1dSLionel Sambuc return a * b; 45*0a6a1f1dSLionel Sambuc if (sa == sb) 46*0a6a1f1dSLionel Sambuc { 47*0a6a1f1dSLionel Sambuc if (abs_a > MAX / abs_b) 48*0a6a1f1dSLionel Sambuc compilerrt_abort(); 49*0a6a1f1dSLionel Sambuc } 50*0a6a1f1dSLionel Sambuc else 51*0a6a1f1dSLionel Sambuc { 52*0a6a1f1dSLionel Sambuc if (abs_a > MIN / -abs_b) 53*0a6a1f1dSLionel Sambuc compilerrt_abort(); 54*0a6a1f1dSLionel Sambuc } 55*0a6a1f1dSLionel Sambuc return a * b; 56*0a6a1f1dSLionel Sambuc } 57