Is handwritten faster?

[Adam Smalin]

I have a fairly complicated grammar. It's > 1000 lines not including
comments with 6 shift-reduce conflicts and 4 reduce-reduce conflicts. I'm
using %glr-parser because a few states are unreachable unless I use a GLR
although only one is valid by the end of the line.

I'm thinking about writing a parser by hand. My two questions are 1) Is it
easy to write a (correct) parser that isn't efficient/fast? 2) Will I hate
myself because my grammar is very complicated? I could create two bison
parsers as another option but IDK how efficient it is versus a hand written
parser. For example if you look at the code below I'd do one pass for the
variables/functions then another for each function.

I'm trying to avoid trees. With bison I know I'll execute the if body
before the if but I could just create a char* and printf it later. If I
were to write my own I don't know how complicated the line "c =
a+b*3+atol(e)" will be.

Bison definitely helped me but if I'm trying to be crazy efficient do I
want to write a handmade parser (I kind of do) or do I want to write two
bison parsers? Many rules will be shared in both like declaring a function
can be inside and outside of a function (but an if cannot be outside)

int a, b, c;
void d() {
  a=2
  b=3
  if(rand()> 0.5) {
    c = a+b*3+atol(e)
  } else c=9
  printf("C: %d\n", c);
}
string e="5"