> I’m trying to have the Aarch64 gcc optimize a single function using the O3 > optimization in this manner: > > void __attribute__ ((optimize ("-O3", "-ftree-vectorize" ))) > However, when examining the assembler code, there is no trace of any > optimization beyond the project...
Greetings, I’m trying to have the Aarch64 gcc optimize a single function using the O3 optimization in this manner: void __attribute__ ((optimize ("-O3", "-ftree-vectorize" ))) However, when examining the assembler code, there is no trace of any optimization beyond the project default...
我注意到的一件事是,GCC 将通过将其编译为a*a来优化呼叫pow(a,2) ,但是呼叫pow(a,6)未被优化并且实际上将调用库函数pow ,这大大减慢了表现。 (相比之下, 英特尔 C ++ 编译器 ,可执行的icc ,将消除对pow(a,6)的库调用。) 我很好奇的是,当我用a*a*a*a*a*a替换pow(a,6)时使用 GCC 4.5....
Optimize even more. GCC performs nearly all supported optimizations that do not involve a space-speed tradeoff. The compiler does not perform loop unrolling or function inlining when you specify `-O2 '. As compared to `-O ', this option increases both compilation time and the performance of t...
诀窍是让编译器相信特定代码段的行为实际上是可观察的。由于这是微基准测试中经常遇到的问题，我建议你...
编译器产生的代码必须具有标准规定的 * 可观察行为 *。任何不可观察的行为都可以随意更改（和优化），...
Optimize even more. GCC performs nearly all supported optimizations that do not involve a space-speed tradeoff. The compiler does not perform loop unrolling or function inlining when you specify `-O2 '. As compared to `-O ', this option increases ...
This attribute should be used for debugging purposes only. It is not suitable in production code. optimize属性的作用是,在编译时使用指明的优化编译选项,而不用编译命令里指定的优化参数。参数值可以是数字,也可以是字符串。数字就是优化级别。以O开头的字符串被认为是一个优化选项,其他的选项以-f开头。当然...
Optimize even more. GCC performs nearly all supported optimizations that do not involve a space-speed tradeoff.The compiler does not perform loop unrolling or function inlining when you specify `-O2 '.As compared to `-O ',this option increases both compilation time and the performance of the ...
void donotoptimize(){} 字符串然后编译gcc helper.c -c -o helper.o, while (...) { donotoptimize();} 型并通过gcc my_benchmark.cc helper.o连接。这给了我最好的结果(从我的信念,没有开销,但我不能测试,因为我的程序将无法工作没有它:))我认为它也应该能在ICC上工作。如果你启用了链接优化,...