@inbounds cannot be applied to entire functions

[mauro3]

The documentation of @inbounds suggests that it can be applied to whole functions:
http://docs.julialang.org/en/release-0.4/manual/performance-tips/?highlight=inbounds#performance-annotations.

However this suggests that it does not work (similar on 0.3 and 0.4):

julia> @inbounds f(xs, i) = xs[i]

julia> g(xs, i) = @inbounds return xs[i]
g (generic function with 1 method)

julia> code_llvm(f, Tuple{Vector{Int}, Int})

define i64 @julia_f_21403(%jl_value_t*, i64) {
top:
  %2 = add i64 %1, -1
  %3 = getelementptr inbounds %jl_value_t* %0, i64 1
  %4 = bitcast %jl_value_t* %3 to i64*
  %5 = load i64* %4, align 8
  %6 = icmp ult i64 %2, %5
  br i1 %6, label %idxend, label %oob

oob:                                              ; preds = %top
  %7 = alloca i64, align 8
  store i64 %1, i64* %7, align 8
  call void @jl_bounds_error_ints(%jl_value_t* %0, i64* %7, i64 1)
  unreachable

idxend:                                           ; preds = %top
  %8 = bitcast %jl_value_t* %0 to i8**
  %9 = load i8** %8, align 8
  %10 = bitcast i8* %9 to i64*
  %11 = getelementptr i64* %10, i64 %2
  %12 = load i64* %11, align 8
  ret i64 %12
}

julia> code_llvm(g, Tuple{Vector{Int}, Int})

define i64 @julia_g_21404(%jl_value_t*, i64) {
top:
  %2 = add i64 %1, -1
  %3 = bitcast %jl_value_t* %0 to i8**
  %4 = load i8** %3, align 8
  %5 = bitcast i8* %4 to i64*
  %6 = getelementptr i64* %5, i64 %2
  %7 = load i64* %6, align 8
  ret i64 %7
}

[fredrikekre]

Seems fixed; https://docs.julialang.org/en/latest/manual/performance-tips.html#Performance-Annotations-1

[StefanKarpinski]

I still see the bounds checks in f as above.

[fredrikekre]

Ah right, I was too quick. This part

The documentation of @inbounds suggests that it can be applied to whole functions:

is fixed, but that wasn't the issue here.

[yuyichao]

Why is it not the issue here? This is the current expected behavior.

[StefanKarpinski]

Because it would be a better for @inbounds annotations on entire functions to work? And that's what the title of the issue says that the issue is?

[Moelf]

just re-discovered that this does not work. And our docs doesn't say explicitly it doesn't work on function definition?

both @inbounds and @fastmath can be applied to either single expressions or all the expressions that appear within nested blocks of code, e.g., using @inbounds begin or @inbounds for ....

it's hard to tell if function ... end block is an exception