> You can see these decisions being made by passing -gcflags=-m to go build:
That's a very nice feature! I wonder if compilers for other languages have something similar.
That's a very nice feature! I wonder if compilers for other languages have something similar.
The frontend may or may not have its own optimizations and logs tho e.g. rustc now has MIR optimizations (https://rustc-dev-guide.rust-lang.org/mir/optimizations.html) but while you can dump MIR data (https://rustc-dev-guide.rust-lang.org/mir/debugging.html) I don't remember seeing an optimisation log.
At the end of the day, I think it's more likely that you take a look at the assembly and infer problems from there if the profiler doesn't tell you straight. An other difference is the kind of decisions the compiler makes e.g. while a compiler can optimize away allocations in "manual allocation" languages (https://godbolt.org/z/5nEo7xjEr) the allocations are plainly visible, so if they're trivially avoidable... you'll just avoid them.
Using Rust as an example, you'd have something like this:
pub fn match_(&self, path: &str) -> Result<&Rule, Error> {
for rule in self.0.iter() {
if rule.match_(path)? {
return Ok(rule);
}
}
Err(Error)
}
pub fn match_(&self, path: &str) -> Result<Box<Rule>, Error> {
for rule in self.0.iter() {
if rule.match_(path)? {
return Ok(Box::new(rule.clone()));
}
}
Err(Error)
} -XX:+PrintCompilation -XX:+UnlockDiagnosticVMOptions -XX:+PrintInlining
-XX:+UnlockDiagnosticVMOptions -XX:+LogCompilation