Analysis of information sources in references of the Wikipedia article "Fortran" in Chinese language version.
The Fortran I compiler was the first major project in code optimization. It tackled problems of crucial importance whose general solution was an important research focus in compiler technology for several decades. Many classical techniques for compiler analysis and optimization can trace their origins and inspiration to the Fortran I compiler.
The Fortran I compiler was the first major project in code optimization. It tackled problems of crucial importance whose general solution was an important research focus in compiler technology for several decades. Many classical techniques for compiler analysis and optimization can trace their origins and inspiration to the Fortran I compiler.
The Fortran I compiler was the first major project in code optimization. It tackled problems of crucial importance whose general solution was an important research focus in compiler technology for several decades. Many classical techniques for compiler analysis and optimization can trace their origins and inspiration to the Fortran I compiler.
The Fortran I compiler was the first major project in code optimization. It tackled problems of crucial importance whose general solution was an important research focus in compiler technology for several decades. Many classical techniques for compiler analysis and optimization can trace their origins and inspiration to the Fortran I compiler.
IF
的话,会消耗4个指令词,需要把常数零放入存储中,然后执行三个机器循环,而如果使用转换指令来实现IF
的话,只需要1到3个指令词就够了,不需要将常数存入存储,只需要1到3个机器循环来执行。一个优化的编译器如FORTRAN最有可能采用的是更精简的和通常来说更快的转换指令,而不是比较指令(使用指换指令同时也允许FREQUENCY
语句来优化IF
,而如果使用比较指令的话则无法实现)。同时,比较指令还将-0和+0认为是不同的值,而转换零和转换非零语句将它们视为相同的值。