There is another item where Fortran is different than C - and potentially faster. Fortran has better optimization rules than C. In Fortran, the evaluation order of an expressions is not defined, which allows the compiler to optimize it - if one wants to force a certain order, one has to use parentheses. In C the order is much stricter, but with "-fast" options, they are more relaxed and "(...)" are also ignored. I think Fortran has a way which lies nicely in the middle. (Well, IEEE makes the live more difficult as certain evaluation-order changes require that no overflows occur, which either has to be ignored or hampers the evaluation).

另一个更聪明的规则领域是复数。这不仅是因为直到c99才有了它们，而且Fortran中管理它们的规则更好;由于gfortran的Fortran库部分是用C编写的，但实现了Fortran语义，GCC获得了这个选项(也可以用于“普通”C程序):

-fcx-fortran-rules 复杂的乘法和除法遵循Fortran规则。范围缩减是作为复杂除法的一部分进行的，但是没有检查复杂乘法或除法的结果是否是“NaN + I*NaN”，试图在这种情况下挽救这种情况。

The alias rules mentioned above is another bonus and also - at least in principle - the whole-array operations, which if taken properly into account by the optimizer of the compiler, can lead faster code. On the contra side are that certain operation take more time, e.g. if one does an assignment to an allocatable array, there are lots of checks necessary (reallocate? [Fortran 2003 feature], has the array strides, etc.), which make the simple operation more complex behind the scenes - and thus slower, but makes the language more powerful. On the other hand, the array operations with flexible bounds and strides makes it easier to write code - and the compiler is usually better optimizing code than a user.

总的来说，我认为C和Fortran的速度差不多;选择应该更多的是你更喜欢哪种语言，或者是使用Fortran的全数组操作及其更好的可移植性更有用，还是使用C中更好的系统接口和图形用户界面库。

Fortran traditionally doesn't set options such as -fp:strict (which ifort requires to enable some of the features in USE IEEE_arithmetic, a part of f2003 standard). Intel C++ also doesn't set -fp:strict as a default, but that is required for ERRNO handling, for example, and other C++ compilers don't make it convenient to turn off ERRNO or gain optimizations such as simd reduction. gcc and g++ have required me to set up Makefile to avoid using the dangerous combination -O3 -ffast-math -fopenmp -march=native. Other than these issues, this question about relative performance gets more nit-picky and dependent on local rules about choice of compilers and options.

我将Fortran、C和c++的速度与netlib中的经典Levine-Callahan-Dongarra基准进行了比较。使用OpenMP的多语言版本是 http://sites.google.com/site/tprincesite/levine-callahan-dongarra-vectors C语言更丑陋，因为它一开始是自动翻译，加上某些编译器的限制和pragmas插入。 c++就是在适用的地方使用STL模板的C。在我看来，STL在是否能提高可维护性方面好坏参半。

为了了解自动函数内联在多大程度上改进了优化，只需要进行很少的练习，因为示例基于传统的Fortran实践，其中很少依赖内联。

到目前为止使用最广泛的C/ c++编译器缺乏自动向量化，而这些基准测试严重依赖于此。

关于这之前的帖子:在Fortran中使用括号来指示更快或更准确的求值顺序的例子有两个。已知的C编译器没有在不禁用更重要的优化的情况下观察括号的选项。

Fortran可以非常方便地处理数组，特别是多维数组。在Fortran中对多维数组元素进行切片比在C/ c++中容易得多。c++现在有库可以做这项工作，比如Boost或Eigen，但它们毕竟是外部库。在Fortran中，这些函数是固有的。

对于开发来说，Fortran是更快还是更方便主要取决于您需要完成的工作。作为地球物理的科学计算人员，我用Fortran(我指的是现代Fortran， >=F90)进行了大部分计算。

我是一个业余程序员，在这两种语言上我都是“平均”。 我发现编写快速Fortran代码比编写C(或c++)代码更容易。Fortran和C都是“历史悠久”的语言(按照今天的标准)，被大量使用，并且很好地支持免费和商业编译器。

我不知道这是否是一个历史事实，但Fortran感觉它是为并行/分布式/向量化/多核化而构建的。今天，当我们谈论速度时，它几乎是“标准度量”:“它能缩放吗?”

对于纯粹的cpu计算，我喜欢Fortran。对于任何与IO相关的东西，我发现使用c更容易(无论如何这两种情况都很困难)。

当然，对于并行计算密集型代码，你可能需要使用GPU。C和Fortran都有很多或多或少很好地集成了CUDA/OpenCL接口(现在还有OpenACC)。

我比较客观的回答是:如果你对这两种语言都同样了解或不了解，那么我认为Fortran更快，因为我发现用Fortran写并行/分布式代码比用c更容易(一旦你明白你可以写“自由形式”Fortran，而不仅仅是严格的F77代码)

Here is a 2nd answer for those willing to downvote me because they don't like the 1st answer : Both language have the features required to write high-performance code. So it's dependent of the algorithm you're implementing (cpu intensive ? io intensive ? memory intensive?), the hardware (single cpu ? multi-core ? distribute supercomputer ? GPGPU ? FPGA ?), your skill and ultimately the compiler itself. Both C and Fortran have awesome compiler. (i'm seriously amazed by how advanced Fortran compilers are but so are C compilers).

PS:我很高兴你特别排除了库，因为我有很多关于Fortran GUI库的不好的东西要说。：）

I think the key point in favor of Fortran is that it is a language slightly more suited for expressing vector- and array-based math. The pointer analysis issue pointed out above is real in practice, since portable code cannot really assume that you can tell a compiler something. There is ALWAYS an advantage to expression computaitons in a manner closer to how the domain looks. C does not really have arrays at all, if you look closely, just something that kind of behaves like it. Fortran has real arrawys. Which makes it easier to compile for certain types of algorithms especially for parallel machines.

在运行时系统和调用约定等方面，C语言和现代的Fortran非常相似，很难看出有什么不同。注意，这里的C实际上是基础C: c++是一个完全不同的问题，具有非常不同的性能特征。