128-bit

Is there any c compiler on windows able to use 128 bit integers natively? On example, you can use gcc on linux, with __uint128_t... any other chance on windows? (It would be great if 128 bit worked on 32 bit computers as well! :D) Matteo Kerrek SB In GCC you can try `` attribute ((mode(...)))`, see here and here , e.g. typedef unsigned int myU128 __attribute__((mode(TI))); The results depend on your platform, though. You could try using SSE intrinsics built into Visual C++ http://msdn.microsoft.com/en-us/library/5eawz414%28v=VS.80%29.aspx (Look at the __m128 type). 来源： https://stackoverflow

I have medium size C99 program which uses long double type (80bit) for floating-point computation. I want to improve precision with new GCC 4.6 extension __float128 . As I get, it is a software-emulated 128-bit precision math. How should I convert my program from classic long double of 80-bit to quad floats of 128 bit with software emulation of full precision? What need I change? Compiler flags, sources? My program have reading of full precision values with strtod , doing a lot of different operations on them (like +-*/ sin, cos, exp and other from <math.h> ) and printf -ing of them. PS:

I checked the size of a pointer in my python terminal (in Enthought Canopy IDE) via import ctypes print (ctypes.sizeof(ctypes.c_voidp) * 8) I've a 64bit architecture and working with numpy.float64 is just fine. But I cannot use np.float128 ? np.array([1,1,1],dtype=np.float128) or np.float128(1) results in: AttributeError: 'module' object has no attribute 'float128' I'm running the following version: sys.version_info(major=2, minor=7, micro=6, releaselevel='final', serial=0) Update: From the comments, it seems pointless to even have a 128 bit float on a 64 bit system. I am using anaconda on a

I've got four unsigned 32-bit integers representing an unsigned 128-bit integer, in little endian order: typedef struct { unsigned int part[4]; } bigint_t; I'd like to convert this number into its decimal string representation and output it to a file. Right now, I'm using a bigint_divmod10 function to divide the number by 10, keeping track of the remainder. I call this function repeatedly, outputting the remainder as a digit, until the number is zero. It's pretty slow. Is this the fastest way to do it? If so, is there a clever way to implement this function that I'm not seeing? I've tried

I'm wondering if there really is no 128-bit division intrinsic function in Visual C++? There is a 64x64=128 bit multiplication intrinsic function called _umul128() , which nicely matches the MUL x64 assembler instruction. Naturally, I assumed there would be a 128/64=64 bit division intrinsic as well (modelling the DIV instruction), but to my amazement neither Visual C++ nor Intel C++ seem to have it, at least it's not listed in intrin.h. Can someone confirm that? I tried grep'ing for the function names in the compiler executable files, but couldn't find _umul128 in the first place, so I guess

gcc 4.4 seems to be the first version when they added int128_t . I need to use bit shifting and I have run out of room for some bit fields. Edit : It might be because I'm on a 32-bit computer, there's no way to have it for a 32-bit computer (Intel Atom), is there? I wouldn't care if it generated tricky slow machine code if I would work as expected with bit shifting. janm I'm pretty sure that __int128_t is available on earlier versions of gcc. Just checked on 4.2.1 and FreeBSD and sizeof(__int128_t) gives 16. You could also use a library. This would have the advantage that it is portable

This question already has an answer here: Is there a 128 bit integer in gcc? 3 answers Does gcc support 128-bit int on amd64? How to define it? How to use scanf/printf to read/write it? rkhayrov GCC supports built-in __int128 and unsigned __int128 types (on 64-bit platforms only), but it looks like formatting support for 128-bit integers is less common in libc. Note: <stdint.h> defines __int128_t and __uint128_t on versions before gcc4.6. See also Is there a 128 bit integer in gcc? for a table of gcc/clang/ICC versions. How to know if __uint128_t is defined for detecting __int128 void f(_