Can you open an issue? It looks like it's still emitting a gc-frame, even though it isn't using it.
On Monday, October 20, 2014, Sebastian Good < [email protected]> wrote: > Your'e right! Sloppy case-minimizing-and-pasting; my apologies. I forgot > to define the conversion. Try this > > julia> import Base.convert > > julia> bitstype 8 Foo > > julia> convert(::Type{Foo}, x::Uint8) = reinterpret(Foo, x) > convert (generic function with 443 methods) > > julia> @code_llvm convert(Uint8, 0x10) > > define i8 @"julia_convert;19713"(%jl_value_t*, i8) { > top: > ret i8 %1, !dbg !741 > } > > julia> @code_llvm convert(Foo, 0x10) > > define i8 @"julia_convert;19716"(%jl_value_t*, i8) { > top: > %2 = alloca [4 x %jl_value_t*], align 8 > %.sub = getelementptr inbounds [4 x %jl_value_t*]* %2, i64 0, i64 0 > store %jl_value_t* inttoptr (i64 4 to %jl_value_t*), %jl_value_t** > %.sub, align 8 > %3 = load %jl_value_t*** @jl_pgcstack, align 8, !dbg !751 > %4 = getelementptr [4 x %jl_value_t*]* %2, i64 0, i64 1, !dbg !751 > %.c = bitcast %jl_value_t** %3 to %jl_value_t*, !dbg !751 > store %jl_value_t* %.c, %jl_value_t** %4, align 8, !dbg !751 > store %jl_value_t** %.sub, %jl_value_t*** @jl_pgcstack, align 8, !dbg > !751 > %5 = getelementptr [4 x %jl_value_t*]* %2, i64 0, i64 2 > store %jl_value_t* null, %jl_value_t** %5, align 8 > %6 = getelementptr [4 x %jl_value_t*]* %2, i64 0, i64 3 > store %jl_value_t* null, %jl_value_t** %6, align 8 > %7 = load %jl_value_t** %4, align 8, !dbg !752 > %8 = getelementptr inbounds %jl_value_t* %7, i64 0, i32 0, !dbg !752 > store %jl_value_t** %8, %jl_value_t*** @jl_pgcstack, align 8, !dbg !752 > ret i8 %1, !dbg !752 > } > > julia> convert(Foo, 0x10) > Foo(0x10) > > julia> convert(Uint8, 0x10) > 0x10 > > > *Sebastian Good* > > > On Mon, Oct 20, 2014 at 11:29 AM, Stefan Karpinski <[email protected] > <javascript:_e(%7B%7D,'cvml','[email protected]');>> wrote: > >> julia> bitstype 8 Foo >> >> julia> convert(Foo, 100) >> ERROR: `convert` has no method matching convert(::Type{Foo}, ::Int64) >> in convert at base.jl:9 >> >> How fast do you want to raise an error? ;-) >> >> On Mon, Oct 20, 2014 at 11:18 AM, Sebastian Good < >> [email protected] >> <javascript:_e(%7B%7D,'cvml','[email protected]');>> >> wrote: >> >>> When I've run benchmarks with custom bitstypes, they seem to run very >>> quickly. But I wouldn't have guessed it from the machine code I can preview >>> at the REPL. Can anyone explain what I'm seeing here? (I'm dumping >>> @code_llvm as it's more instructive; the @code_native is very large). >>> Converting a constant number to a Uint8 is a one-operation function. >>> Converting a constant number to a bitstype of the same size seems to do a >>> lot more. >>> >>> julia> @code_llvm convert(Uint8, 100) >>> >>> define i8 @"julia_convert;19720"(%jl_value_t*, i64) { >>> top: >>> %2 = trunc i64 %1 to i8, !dbg !772, !julia_type !773 >>> ret i8 %2, !dbg !772 >>> } >>> >>> julia> bitstype 8 Foo >>> julia> @code_llvm convert(Foo, 100) >>> >>> ; Function Attrs: noreturn >>> define void @"julia_convert;19725"(%jl_value_t*, i64) #0 { >>> top: >>> %2 = alloca [5 x %jl_value_t*], align 8 >>> %.sub = getelementptr inbounds [5 x %jl_value_t*]* %2, i64 0, i64 0 >>> %3 = getelementptr [5 x %jl_value_t*]* %2, i64 0, i64 2, !dbg !776 >>> store %jl_value_t* inttoptr (i64 6 to %jl_value_t*), %jl_value_t** >>> %.sub, align 8 >>> %4 = load %jl_value_t*** @jl_pgcstack, align 8, !dbg !776 >>> %5 = getelementptr [5 x %jl_value_t*]* %2, i64 0, i64 1, !dbg !776 >>> %.c = bitcast %jl_value_t** %4 to %jl_value_t*, !dbg !776 >>> store %jl_value_t* %.c, %jl_value_t** %5, align 8, !dbg !776 >>> store %jl_value_t** %.sub, %jl_value_t*** @jl_pgcstack, align 8, !dbg >>> !776 >>> store %jl_value_t* null, %jl_value_t** %3, align 8 >>> %6 = getelementptr [5 x %jl_value_t*]* %2, i64 0, i64 3 >>> store %jl_value_t* null, %jl_value_t** %6, align 8 >>> %7 = getelementptr [5 x %jl_value_t*]* %2, i64 0, i64 4 >>> store %jl_value_t* null, %jl_value_t** %7, align 8 >>> %8 = load %jl_value_t** inttoptr (i64 140384830597872 to >>> %jl_value_t**), align 16, !dbg !777 >>> %9 = getelementptr inbounds %jl_value_t* %8, i64 1, i32 0, !dbg !777 >>> %10 = load %jl_value_t** %9, align 8, !dbg !777, !tbaa %jtbaa_func >>> %11 = bitcast %jl_value_t* %10 to %jl_value_t* (%jl_value_t*, >>> %jl_value_t**, i32)*, !dbg !777 >>> store %jl_value_t* %0, %jl_value_t** %3, align 8, !dbg !777 >>> %12 = call %jl_value_t* @jl_box_int64(i64 %1), !dbg !777 >>> store %jl_value_t* %12, %jl_value_t** %6, align 8, !dbg !777 >>> %13 = load %jl_value_t** inttoptr (i64 140384825150528 to >>> %jl_value_t**), align 64, !dbg !777 >>> store %jl_value_t* %13, %jl_value_t** %7, align 8, !dbg !777 >>> %14 = call %jl_value_t* %11(%jl_value_t* %8, %jl_value_t** %3, i32 3), >>> !dbg !777 >>> %15 = load %jl_value_t** %5, align 8, !dbg !777 >>> %16 = getelementptr inbounds %jl_value_t* %15, i64 0, i32 0, !dbg !777 >>> store %jl_value_t** %16, %jl_value_t*** @jl_pgcstack, align 8, !dbg >>> !777 >>> ret void, !dbg !777 >>> } >>> >>> >> >
