有趣的是，这里的很多答案都来自于不懂语言。这对于那些打开过旧的FORTRAN 77代码并讨论过其弱点的C/ c++程序员来说尤其如此。

我认为速度问题主要是C/ c++和Fortran之间的问题。在大型代码中，它总是取决于程序员。有一些语言特性是Fortran优于的，而一些特性是C优于的。所以，在2011年，没有人能真正说出哪一个更快。

About the language itself, Fortran nowadays supports Full OOP features and it is fully backward compatible. I have used the Fortran 2003 thoroughly and I would say it was just delightful to use it. In some aspects, Fortran 2003 is still behind C++ but let's look at the usage. Fortran is mostly used for Numerical Computation, and nobody uses fancy C++ OOP features because of speed reasons. In high performance computing, C++ has almost no place to go(have a look at the MPI standard and you'll see that C++ has been deprecated!).

现在，您可以简单地使用Fortran和C/ c++进行混合语言编程。Fortran中甚至有GTK+的接口。有免费的编译器(gfortran, g95)和许多优秀的商业编译器。

The faster code is not really up to the language, is the compiler so you can see the ms-vb "compiler" that generates bloated, slower and redundant object code that is tied together inside an ".exe", but powerBasic generates too way better code. Object code made by a C and C++ compilers is generated in some phases (at least 2) but by design most Fortran compilers have at least 5 phases including high-level optimizations so by design Fortran will always have the capability to generate highly optimized code. So at the end is the compiler not the language you should ask for, the best compiler i know is the Intel Fortran Compiler because you can get it on LINUX and Windows and you can use VS as the IDE, if you're looking for a cheap tigh compiler you can always relay on OpenWatcom.

更多信息: http://ed-thelen.org/1401Project/1401-IBM-Systems-Journal-FORTRAN.html

我还没有听说过Fortan比C快得多，但是可以想象在某些情况下它会更快。关键不在于语言特征的存在，而在于那些(通常)不存在的特征。

一个例子是C指针。C指针几乎到处都在使用，但指针的问题是编译器通常无法判断它们是否指向同一个数组的不同部分。

例如，如果你写了一个strcpy例程，看起来像这样:

strcpy(char *d, const char* s)
{
  while(*d++ = *s++);
}

编译器必须在d和s可能是重叠数组的假设下工作。所以当数组重叠时，它不能执行会产生不同结果的优化。正如您所期望的，这在很大程度上限制了可以执行的优化类型。

[我应该注意到，C99有一个“restrict”关键字，显式地告诉编译器指针不重叠。还要注意，Fortran也有指针，语义不同于C语言，但指针不像C语言那样无处不在。

但是回到C与Fortran的问题上，可以想象，Fortran编译器能够执行一些对于(直接编写的)C程序可能无法实现的优化。所以我不会对这种说法感到太惊讶。不过，我确实希望性能差异不会太大。(~ 5 - 10%)

没有一种语言比另一种语言更快，所以正确的答案是否定的。

你真正要问的是“用Fortran编译器X编译的代码是否比用C编译器Y编译的等效代码更快?”这个问题的答案当然取决于您选择哪两个编译器。

人们可能会问的另一个问题是“考虑到在他们的编译器中优化投入了相同的精力，哪个编译器会生成更快的代码?” 这个问题的答案实际上是Fortran。Fortran编译器有一些优势:

Fortran had to compete with Assembly back in the day when some vowed never to use compilers, so it was designed for speed. C was designed to be flexible. Fortran's niche has been number crunching. In this domain code is never fast enough. So there's always been a lot of pressure to keep the language efficient. Most of the research in compiler optimizations is done by people interested in speeding up Fortran number crunching code, so optimizing Fortran code is a much better known problem than optimizing any other compiled language, and new innovations show up in Fortran compilers first. Biggie: C encourages much more pointer use than Fortran. This drasticly increases the potential scope of any data item in a C program, which makes them far harder to optimize. Note that Ada is also way better than C in this realm, and is a much more modern OO Language than the commonly found Fortran77. If you want an OO langauge that can generate faster code than C, this is an option for you. Due again to its number-crunching niche, the customers of Fortran compilers tend to care more about optimization than the customers of C compilers.

然而，没有什么能阻止人们在C编译器的优化上投入大量精力，并使其生成比他们平台的Fortran编译器更好的代码。事实上，C编译器产生的较大销售额使得这种情况非常可行

有趣的是，这里的很多答案都来自于不懂语言。这对于那些打开过旧的FORTRAN 77代码并讨论过其弱点的C/ c++程序员来说尤其如此。

我认为速度问题主要是C/ c++和Fortran之间的问题。在大型代码中，它总是取决于程序员。有一些语言特性是Fortran优于的，而一些特性是C优于的。所以，在2011年，没有人能真正说出哪一个更快。

About the language itself, Fortran nowadays supports Full OOP features and it is fully backward compatible. I have used the Fortran 2003 thoroughly and I would say it was just delightful to use it. In some aspects, Fortran 2003 is still behind C++ but let's look at the usage. Fortran is mostly used for Numerical Computation, and nobody uses fancy C++ OOP features because of speed reasons. In high performance computing, C++ has almost no place to go(have a look at the MPI standard and you'll see that C++ has been deprecated!).

现在，您可以简单地使用Fortran和C/ c++进行混合语言编程。Fortran中甚至有GTK+的接口。有免费的编译器(gfortran, g95)和许多优秀的商业编译器。

Fortran速度更快有几个原因。然而，它们的重要性是如此无关紧要，或者可以通过任何方式解决，所以它不应该是重要的。现在使用Fortran的主要原因是维护或扩展遗留应用程序。

PURE and ELEMENTAL keywords on functions. These are functions that have no side effects. This allows optimizations in certain cases where the compiler knows the same function will be called with the same values. Note: GCC implements "pure" as an extension to the language. Other compilers may as well. Inter-module analysis can also perform this optimization but it is difficult. standard set of functions that deal with arrays, not individual elements. Stuff like sin(), log(), sqrt() take arrays instead of scalars. This makes it easier to optimize the routine. Auto-vectorization gives the same benefits in most cases if these functions are inline or builtins Builtin complex type. In theory this could allow the compiler to reorder or eliminate certain instructions in certain cases, but likely you'd see the same benefit with the struct { double re; double im; }; idiom used in C. It makes for faster development though as operators work on complex types in Fortran.