g++优化开关（暴力必备）

 1 %:pragma GCC optimize()
 %:pragma GCC optimize("Ofast")
 %:pragma GCC optimize("inline")
 %:pragma GCC optimize("-fgcse")
 %:pragma GCC optimize("-fgcse-lm")
 %:pragma GCC optimize("-fipa-sra")
 %:pragma GCC optimize("-ftree-pre")
 %:pragma GCC optimize("-ftree-vrp")
 %:pragma GCC optimize("-fpeephole2")
 %:pragma GCC optimize("-ffast-math")
 %:pragma GCC optimize("-fsched-spec")
 %:pragma GCC optimize("unroll-loops")
 %:pragma GCC optimize("-falign-jumps")
 %:pragma GCC optimize("-falign-loops")
 %:pragma GCC optimize("-falign-labels")
 %:pragma GCC optimize("-fdevirtualize")
 %:pragma GCC optimize("-fcaller-saves")
 %:pragma GCC optimize("-fcrossjumping")
 %:pragma GCC optimize("-fthread-jumps")
 %:pragma GCC optimize("-funroll-loops")
 %:pragma GCC optimize("-fwhole-program")
 %:pragma GCC optimize("-freorder-blocks")
 %:pragma GCC optimize("-fschedule-insns")
 %:pragma GCC optimize("inline-functions")
 %:pragma GCC optimize("-ftree-tail-merge")
 %:pragma GCC optimize("-fschedule-insns2")
 %:pragma GCC optimize("-fstrict-aliasing")
 %:pragma GCC optimize("-fstrict-overflow")
 %:pragma GCC optimize("-falign-functions")
 %:pragma GCC optimize("-fcse-skip-blocks")
 %:pragma GCC optimize("-fcse-follow-jumps")
 %:pragma GCC optimize("-fsched-interblock")
 %:pragma GCC optimize("-fpartial-inlining")
 %:pragma GCC optimize("no-stack-protector")
 %:pragma GCC optimize("-freorder-functions")
 %:pragma GCC optimize("-findirect-inlining")
 %:pragma GCC optimize("-fhoist-adjacent-loads")
 %:pragma GCC optimize("-frerun-cse-after-loop")
 %:pragma GCC optimize("inline-small-functions")
 %:pragma GCC optimize("-finline-small-functions")
 %:pragma GCC optimize("-ftree-switch-conversion")
 %:pragma GCC optimize("-foptimize-sibling-calls")
 %:pragma GCC optimize("-fexpensive-optimizations")
 %:pragma GCC optimize("-funsafe-loop-optimizations")
 %:pragma GCC optimize("inline-functions-called-once")
 %:pragma GCC optimize("-fdelete-null-pointer-checks")

真好。