# Shouldn't 1.8.0 be faster than Julia 1.7?

**URL:** <https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143>\
**Category:** Performance\
**Created:** [June 2, 2022, 3:44pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143 "2022-06-02T15:44:20Z")\
**Posts on this page:** 20\
**Page:** 1

<div class="post-metadata">

**Author:** ![mindaslab](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mindaslab/32/12673_2.png) [@mindaslab](https://discourse.julialang.org/u/mindaslab)\
**Post date:** [June 2, 2022, 3:44pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/1 "2022-06-02T15:44:20Z")

</div>

![Screen Shot 2022-06-02 at 9.06.55 PM](https://global.discourse-cdn.com/julialang/original/3X/5/6/56a5581b8d75083677f611725885f91696ac098e.png)

 ![Screen Shot 2022-06-02 at 9.07.52 PM](https://global.discourse-cdn.com/julialang/original/3X/d/6/d64b318a5531b14a8d069f89db23dd23dcc39d3a.png)

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<div class="post-metadata">

**Author:** ![Tomas\_Pevny](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tomas_pevny/32/25466_2.png) [@Tomas\_Pevny](https://discourse.julialang.org/u/Tomas_Pevny)\
**Post date:** [June 2, 2022, 3:45pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/2 "2022-06-02T15:45:36Z")

</div>

Are you measuring compile time?

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<div class="post-metadata">

**Author:** ![mindaslab](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mindaslab/32/12673_2.png) [@mindaslab](https://discourse.julialang.org/u/mindaslab)\
**Post date:** [June 2, 2022, 3:47pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/3 "2022-06-02T15:47:05Z")

</div>

I am not sure what `@time` really does. I thought things will get faster in Julia.

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<div class="post-metadata">

**Author:** ![Tomas\_Pevny](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tomas_pevny/32/25466_2.png) [@Tomas\_Pevny](https://discourse.julialang.org/u/Tomas_Pevny)\
**Post date:** [June 2, 2022, 3:48pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/4 "2022-06-02T15:48:05Z")

</div>

Can you run the command twice?  
While compilation time is important, the running time is even more important.

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<div class="post-metadata">

**Author:** ![mbauman](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mbauman/32/31082_2.png) [@mbauman](https://discourse.julialang.org/u/mbauman)\
**Post date:** [June 2, 2022, 3:54pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/5 "2022-06-02T15:54:37Z")

</div>

This is a silly benchmark that is almost certainly hitting swap. Run it again and you’ll likely see wildly varying numbers on all versions of Julia depending upon what else is happening on your computer and how much memory you have available.

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<div class="post-metadata">

**Author:** ![Tomas\_Pevny](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tomas_pevny/32/25466_2.png) [@Tomas\_Pevny](https://discourse.julialang.org/u/Tomas_Pevny)\
**Post date:** [June 2, 2022, 3:59pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/6 "2022-06-02T15:59:58Z")

</div>

To finish this,

I have `@benchmark` it. As @mbauman said, the variance is huge, median is the same

 ![Screenshot 2022-06-02 at 17.58.41](https://global.discourse-cdn.com/julialang/original/3X/6/d/6d895abb662ad1b92a4a86ef4a0ece5b924780dd.png)

 ![Screenshot 2022-06-02 at 17.58.49](https://global.discourse-cdn.com/julialang/original/3X/4/c/4c02067eb171d2e9a0f2eb0228e8aaf8fd290fb4.png)

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<div class="post-metadata">

**Author:** ![mindaslab](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mindaslab/32/12673_2.png) [@mindaslab](https://discourse.julialang.org/u/mindaslab)\
**Post date:** [June 2, 2022, 4:01pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/7 "2022-06-02T16:01:15Z")

</div>

Looks lime my computer is been consistently silly for more than 5 minutes

 ![image](https://global.discourse-cdn.com/julialang/original/3X/2/3/23e721a4b7a203cb33b3b22b577e949739a0daa8.jpeg)

 ![image](https://global.discourse-cdn.com/julialang/original/3X/0/7/07864130d7d5e1fe47442e743fc7602f4aff7e9a.jpeg)

Should see if its varying widely tomorrow.

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<div class="post-metadata">

**Author:** ![mbauman](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mbauman/32/31082_2.png) [@mbauman](https://discourse.julialang.org/u/mbauman)\
**Post date:** [June 2, 2022, 4:03pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/8 "2022-06-02T16:03:08Z")

</div>

Seriously, this is not meaningful.

Sometimes when you run the “test”, _your operating system_ needs to make space for a 7GB array. Sometimes, that space is already available.

That overhead has nothing to do with Julia versions.

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<div class="post-metadata">

**Author:** ![Sukera](https://avatars.discourse-cdn.com/v4/letter/s/ce7236/32.png) [@Sukera](https://discourse.julialang.org/u/Sukera)\
**Post date:** [June 2, 2022, 4:04pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/9 "2022-06-02T16:04:08Z")

</div>

Let’s not jump to conclusions about whether a benchmark is silly or not. @mbauman You don’t even know anything about the machine they’re running it on.

FWIW, I can also see a slowdown, though not as drastic. I’m running this on a machine with 20GB RAM, with plenty free to fit everything without having to swap.

```julia
julia> @time (1:10^9).^2;
  3.392685 seconds (2 allocations: 7.451 GiB, 0.24% gc time)

julia> GC.gc()

julia> @time (1:10^9).^2;
  3.690638 seconds (2 allocations: 7.451 GiB, 9.07% gc time)

julia> GC.gc()

julia> versioninfo()
Julia Version 1.7.3
Commit 742b9abb4d (2022-05-06 12:58 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: Intel(R) Core(TM) i7-6600U CPU @ 2.60GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-12.0.1 (ORCJIT, skylake)
Environment:
  JULIA_NUM_THREADS = 4

```

vs.

```julia
julia> @time (1:10^9).^2;
  5.470563 seconds (2 allocations: 7.451 GiB, 0.17% gc time)

julia> @time (1:10^9).^2;
  5.437031 seconds (2 allocations: 7.451 GiB, 0.11% gc time)

julia> GC.gc()

julia> @time (1:10^9).^2;
  5.735879 seconds (2 allocations: 7.451 GiB, 4.50% gc time)

julia> versioninfo()
Julia Version 1.9.0-DEV.614
Commit 0488abc625* (2022-05-24 15:28 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: 4 × Intel(R) Core(TM) i7-6600U CPU @ 2.60GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-13.0.1 (ORCJIT, skylake)
  Threads: 4 on 4 virtual cores
Environment:
  JULIA_NUM_THREADS = 4

```

@mindaslab could you post the output of `versioninfo(;verbose=true)` please?

–

Julia is not guaranteed to make every operation faster with a new version, but I do have to agree that the benchmark is kind of arbitrary and literally only measures a single allocation and application of a single function. It’s not representative of all things you can do, so concluding that 1.8 is in general slower seems a little premature to me (especially considering that a great deal of _other_ issues have gotten substantially faster).

---

<div class="post-metadata">

**Author:** ![Sukera](https://avatars.discourse-cdn.com/v4/letter/s/ce7236/32.png) [@Sukera](https://discourse.julialang.org/u/Sukera)\
**Post date:** [June 2, 2022, 4:09pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/10 "2022-06-02T16:09:34Z")

</div>

Apologies, that output above does not include the full picture. Here’s my output of `versioninfo(;verbose=true)`, minus my `PATH`:

```julia
julia> versioninfo(;verbose=true)
Julia Version 1.9.0-DEV.614
Commit 0488abc625* (2022-05-24 15:28 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
      "Arch Linux"
  uname: Linux 5.17.9-arch1-1 #1 SMP PREEMPT Wed, 18 May 2022 17:30:11 +0000 x86_64 unknown
  CPU: Intel(R) Core(TM) i7-6600U CPU @ 2.60GHz: 
              speed user nice sys idle irq
       #1 2418 MHz 97177 s 65 s 21188 s 184522 s 4351 s
       #2 2800 MHz 99033 s 65 s 21217 s 184243 s 2350 s
       #3 2800 MHz 102550 s 72 s 19599 s 183762 s 1928 s
       #4 2800 MHz 100925 s 64 s 22680 s 182784 s 2273 s
  Memory: 19.400531768798828 GB (15737.29296875 MB free)
  Uptime: 31265.1 sec
  Load Avg: 1.15 1.29 2.09
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-13.0.1 (ORCJIT, skylake)
  Threads: 4 on 4 virtual cores
Environment:
  JULIA_NUM_THREADS = 4
  HOME = /home/sukera
  TERM = foot

```

---

<div class="post-metadata">

**Author:** ![Oscar\_Smith](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/oscar_smith/32/25343_2.png) [@Oscar\_Smith](https://discourse.julialang.org/u/Oscar_Smith)\
**Post date:** [June 2, 2022, 4:18pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/11 "2022-06-02T16:18:14Z")

</div>

is there a difference in the `@code_native`?

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<div class="post-metadata">

**Author:** ![gbaraldi](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/gbaraldi/32/22101_2.png) [@gbaraldi](https://discourse.julialang.org/u/gbaraldi)\
**Post date:** [June 2, 2022, 4:22pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/12 "2022-06-02T16:22:48Z")

</div>

The code is different for sure. I can also replicate the regression, in my computer it’s only about 25%, but it’s there.

---

<div class="post-metadata">

**Author:** ![Sukera](https://avatars.discourse-cdn.com/v4/letter/s/ce7236/32.png) [@Sukera](https://discourse.julialang.org/u/Sukera)\
**Post date:** [June 2, 2022, 4:25pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/13 "2022-06-02T16:25:55Z")

</div>

Yes, but I’m not sure how much is due to a difference in code used.

> **1.7.3**
>
> ```julia
> julia> @code_native (1:10^9).^2;
> .text
> ; ┌ @ none within `##dotfunction#291#1`
> pushq	%rbp
> pushq	%r15
> pushq	%r14
> pushq	%r13
> pushq	%r12
> pushq	%rbx
> subq	$56, %rsp
> movq	%rsi, %r14
> vxorps	%xmm0, %xmm0, %xmm0
> vmovaps	%xmm0, (%rsp)
> movq	$0, 16(%rsp)
> movq	%fs:0, %rax
> movq	-8(%rax), %rcx
> ; │┌ @ broadcast.jl:860 within `materialize`
> ; ││┌ @ broadcast.jl:281 within `instantiate`
> ; │││┌ @ broadcast.jl:499 within `combine_axes`
> ; ││││┌ @ range.jl:643 within `axes`
> ; │││││┌ @ range.jl:699 within `length`
> ; ││││││┌ @ range.jl:775 within `last`
> ; │││││││┌ @ Base.jl:42 within `getproperty`
> movq	$4, (%rsp)
> movq	(%rcx), %rax
> movq	%rax, 8(%rsp)
> movq	%rsp, %rax
> movq	%rcx, 32(%rsp)
> movq	%rax, (%rcx)
> ; ││││││└└
> ; ││││││┌ @ int.jl:86 within `-`
> movq	(%rdi), %r15
> movq	8(%rdi), %rbp
> subq	%r15, %rbp
> ; │││││└└
> ; │││││┌ @ range.jl:700 within `length`
> ; ││││││┌ @ int.jl:87 within `+`
> leaq	1(%rbp), %r13
> ; │││││└└
> ; │││││┌ @ range.jl:413 within `oneto`
> ; ││││││┌ @ range.jl:411 within `OneTo` @ range.jl:398
> ; │││││││┌ @ promotion.jl:479 within `max`
> movq	%r13, %rax
> sarq	$63, %rax
> andnq	%r13, %rax, %r12
> ; ││││└└└└
> ; ││││┌ @ broadcast.jl:504 within `broadcast_shape`
> ; │││││┌ @ broadcast.jl:508 within `_bcs`
> movq	%r12, 48(%rsp)
> movabsq	$jl_system_image_data, %rdi
> movabsq	$140407002443377, %rax # imm = 0x7FB30D812E71
> ; ││└└└└
> ; ││┌ @ broadcast.jl:885 within `copy`
> ; │││┌ @ broadcast.jl:211 within `similar` @ broadcast.jl:212 @ abstractarray.jl:828 @ abstractarray.jl:829
> ; ││││┌ @ boot.jl:474 within `Array` @ boot.jl:466 @ boot.jl:457
> movq	%r12, %rsi
> callq	*%rax
> movq	%rax, %rbx
> ; │││└└
> ; │││┌ @ broadcast.jl:913 within `copyto!` @ broadcast.jl:949
> ; ││││┌ @ abstractarray.jl:95 within `axes`
> ; │││││┌ @ array.jl:151 within `size`
> movq	24(%rax), %rax
> ; ││││└└
> ; ││││┌ @ tuple.jl:381 within `==`
> ; │││││┌ @ tuple.jl:385 within `_eq`
> ; ││││││┌ @ range.jl:1043 within `==`
> cmpq	$1, %rax
> je	L183
> testq	%rax, %rax
> jne	L256
> ; │││││││┌ @ range.jl:609 within `isempty`
> ; ││││││││┌ @ operators.jl:378 within `>`
> ; │││││││││┌ @ int.jl:83 within `<`
> testq	%r12, %r12
> ; ││││└└└└└└
> jle	L189
> ; ││││┌ @ abstractarray.jl:95 within `axes`
> ; │││││┌ @ tuple.jl:221 within `map`
> L154:
> movq	%rax, 40(%rsp)
> ; ││││└└
> movabsq	$throwdm, %rax
> leaq	40(%rsp), %rdi
> leaq	48(%rsp), %rsi
> callq	*%rax
> ud2
> ; ││││┌ @ tuple.jl:381 within `==`
> ; │││││┌ @ tuple.jl:385 within `_eq`
> ; ││││││┌ @ range.jl:1044 within `==`
> ; │││││││┌ @ range.jl:1057 within `_has_length_one`
> ; ││││││││┌ @ promotion.jl:468 within `==`
> L183:
> cmpq	$1, %r12
> ; ││││└└└└└
> jne	L154
> ; ││└└
> ; ││┌ @ broadcast.jl:281 within `instantiate`
> ; │││┌ @ broadcast.jl:499 within `combine_axes`
> ; ││││┌ @ range.jl:643 within `axes`
> ; │││││┌ @ range.jl:413 within `oneto`
> ; ││││││┌ @ range.jl:411 within `OneTo` @ range.jl:398
> ; │││││││┌ @ promotion.jl:479 within `max`
> L189:
> testq	%r13, %r13
> ; ││└└└└└└
> ; ││┌ @ broadcast.jl:885 within `copy`
> ; │││┌ @ broadcast.jl:913 within `copyto!` @ broadcast.jl:960
> ; ││││┌ @ simdloop.jl:72 within `macro expansion`
> jle	L317
> ; ││││└
> ; ││││ @ broadcast.jl:913 within `copyto!` @ broadcast.jl:957
> ; ││││┌ @ broadcast.jl:940 within `preprocess`
> ; │││││┌ @ broadcast.jl:943 within `preprocess_args`
> ; ││││││┌ @ broadcast.jl:941 within `preprocess`
> ; │││││││┌ @ broadcast.jl:637 within `extrude`
> ; ││││││││┌ @ broadcast.jl:586 within `newindexer`
> ; │││││││││┌ @ broadcast.jl:587 within `shapeindexer`
> ; ││││││││││┌ @ broadcast.jl:592 within `_newindexer`
> ; │││││││││││┌ @ operators.jl:278 within `!=`
> ; ││││││││││││┌ @ promotion.jl:468 within `==`
> testq	%rbp, %rbp
> ; ││││└└└└└└└└└
> ; ││││ @ broadcast.jl:913 within `copyto!` @ broadcast.jl:960
> ; ││││┌ @ simdloop.jl:75 within `macro expansion`
> je	L263
> ; ││││└
> ; ││││┌ @ simdloop.jl within `macro expansion`
> xorl	%ebp, %ebp
> movabsq	$power_by_squaring, %r13
> nopw	%cs:(%rax,%rax)
> ; ││││└
> ; ││││┌ @ simdloop.jl:77 within `macro expansion` @ broadcast.jl:961
> ; │││││┌ @ broadcast.jl:597 within `getindex`
> ; ││││││┌ @ broadcast.jl:642 within `_broadcast_getindex`
> ; │││││││┌ @ broadcast.jl:666 within `_getindex`
> ; ││││││││┌ @ broadcast.jl:636 within `_broadcast_getindex`
> ; │││││││││┌ @ range.jl:860 within `getindex`
> ; ││││││││││┌ @ int.jl:87 within `+`
> L224:
> leaq	(%r15,%rbp), %rdi
> movq	%rbx, 16(%rsp)
> ; ││││││└└└└└
> ; ││││││┌ @ broadcast.jl:643 within `_broadcast_getindex`
> ; │││││││┌ @ broadcast.jl:670 within `_broadcast_getindex_evalf`
> ; ││││││││┌ @ intfuncs.jl:290 within `^`
> movq	%r14, %rsi
> callq	*%r13
> ; │││││└└└└
> ; │││││┌ @ array.jl:903 within `setindex!`
> movq	(%rbx), %rcx
> movq	%rax, (%rcx,%rbp,8)
> ; ││││└└
> ; ││││┌ @ simdloop.jl:78 within `macro expansion`
> ; │││││┌ @ int.jl:87 within `+`
> incq	%rbp
> ; ││││└└
> ; ││││┌ @ simdloop.jl:75 within `macro expansion`
> ; │││││┌ @ int.jl:83 within `<`
> cmpq	%rbp, %r12
> ; │││││└
> jne	L224
> jmp	L317
> ; ││││└
> ; ││││ @ broadcast.jl:913 within `copyto!` @ broadcast.jl:949
> ; ││││┌ @ tuple.jl:381 within `==`
> ; │││││┌ @ tuple.jl:385 within `_eq`
> ; ││││││┌ @ range.jl:1045 within `==` @ promotion.jl:468
> L256:
> cmpq	%r12, %rax
> je	L189
> jmp	L154
> ; ││││└└└
> ; ││││ @ broadcast.jl:913 within `copyto!` @ promotion.jl:0
> L263:
> xorl	%ebp, %ebp
> movabsq	$power_by_squaring, %r13
> nopw	%cs:(%rax,%rax)
> L288:
> movq	%rbx, 16(%rsp)
> ; ││││ @ broadcast.jl:913 within `copyto!` @ broadcast.jl:960
> ; ││││┌ @ simdloop.jl:77 within `macro expansion` @ broadcast.jl:961
> ; │││││┌ @ broadcast.jl:597 within `getindex`
> ; ││││││┌ @ broadcast.jl:643 within `_broadcast_getindex`
> ; │││││││┌ @ broadcast.jl:670 within `_broadcast_getindex_evalf`
> ; ││││││││┌ @ intfuncs.jl:290 within `^`
> movq	%r15, %rdi
> movq	%r14, %rsi
> callq	*%r13
> ; │││││└└└└
> ; │││││┌ @ array.jl:903 within `setindex!`
> movq	(%rbx), %rcx
> movq	%rax, (%rcx,%rbp,8)
> ; ││││└└
> ; ││││┌ @ simdloop.jl:78 within `macro expansion`
> ; │││││┌ @ int.jl:87 within `+`
> incq	%rbp
> ; ││││└└
> ; ││││┌ @ simdloop.jl:75 within `macro expansion`
> ; │││││┌ @ int.jl:83 within `<`
> cmpq	%rbp, %r12
> ; │││││└
> jne	L288
> ; │└└└└
> ; │ @ simdloop.jl within `##dotfunction#291#1`
> L317:
> movq	8(%rsp), %rax
> movq	32(%rsp), %rcx
> movq	%rax, (%rcx)
> movq	%rbx, %rax
> addq	$56, %rsp
> popq	%rbx
> popq	%r12
> popq	%r13
> popq	%r14
> popq	%r15
> popq	%rbp
> retq
> nopl	(%rax)
> ; └
> 
> ```

> **1.8+/1.9-DEV**
>
> ```julia
> julia> @code_native (1:10^9).^2;
> .text
> .file	"##dotfunction#312#3"
> .globl	"julia_##dotfunction#312#3_61" # -- Begin function julia_##dotfunction#312#3_61
> .p2align	4, 0x90
> .type	"julia_##dotfunction#312#3_61",@function
> "julia_##dotfunction#312#3_61": # @"julia_##dotfunction#312#3_61"
> ; ┌ @ none within `##dotfunction#312#3`
> .cfi_startproc
> # %bb.0: # %top
> pushq	%rbp
> .cfi_def_cfa_offset 16
> pushq	%r15
> .cfi_def_cfa_offset 24
> pushq	%r14
> .cfi_def_cfa_offset 32
> pushq	%r13
> .cfi_def_cfa_offset 40
> pushq	%r12
> .cfi_def_cfa_offset 48
> pushq	%rbx
> .cfi_def_cfa_offset 56
> subq	$56, %rsp
> .cfi_def_cfa_offset 112
> .cfi_offset %rbx, -56
> .cfi_offset %r12, -48
> .cfi_offset %r13, -40
> .cfi_offset %r14, -32
> .cfi_offset %r15, -24
> .cfi_offset %rbp, -16
> vxorps	%xmm0, %xmm0, %xmm0
> vmovaps	%xmm0, (%rsp)
> movq	%rsi, %r14
> movq	$0, 16(%rsp)
> #APP
> movq	%fs:0, %rax
> #NO_APP
> movq	-8(%rax), %rcx
> ; │┌ @ broadcast.jl:860 within `materialize`
> ; ││┌ @ broadcast.jl:281 within `instantiate`
> ; │││┌ @ broadcast.jl:499 within `combine_axes`
> ; ││││┌ @ range.jl:688 within `axes`
> ; │││││┌ @ range.jl:737 within `length`
> ; ││││││┌ @ range.jl:811 within `first`
> ; │││││││┌ @ Base.jl:37 within `getproperty`
> movq	$4, (%rsp)
> movq	(%rcx), %rax
> movq	%rax, 8(%rsp)
> movq	%rsp, %rax
> movq	%rcx, 32(%rsp) # 8-byte Spill
> movq	%rax, (%rcx)
> ; ││││││└└
> ; ││││││ @ range.jl:740 within `length`
> ; ││││││┌ @ int.jl:86 within `-`
> movq	(%rdi), %rax
> movq	8(%rdi), %r12
> movq	%r12, %r13
> movq	%rax, %rbp
> subq	%rax, %r13
> ; ││││││└
> ; ││││││┌ @ int.jl:87 within `+`
> leaq	1(%r13), %rax
> xorl	%r15d, %r15d
> movabsq	$9223372036854775807, %rcx # imm = 0x7FFFFFFFFFFFFFFF
> ; │││││└└
> ; │││││┌ @ range.jl:455 within `oneto`
> ; ││││││┌ @ range.jl:453 within `OneTo` @ range.jl:440
> ; │││││││┌ @ promotion.jl:488 within `max`
> ; ││││││││┌ @ essentials.jl:556 within `ifelse`
> cmpq	%rcx, %r13
> cmovbq	%rax, %r15
> ; ││││└└└└└
> ; ││││┌ @ broadcast.jl:504 within `broadcast_shape`
> ; │││││┌ @ broadcast.jl:508 within `_bcs`
> movq	%r15, 48(%rsp)
> movabsq	$140165121583952, %rdi # imm = 0x7F7ABC482B50
> movabsq	$140165461506848, %rax # imm = 0x7F7AD08AFB20
> ; ││└└└└
> ; ││┌ @ broadcast.jl:885 within `copy`
> ; │││┌ @ broadcast.jl:211 within `similar` @ broadcast.jl:212 @ abstractarray.jl:852 @ abstractarray.jl:853
> ; ││││┌ @ boot.jl:478 within `Array` @ boot.jl:470 @ boot.jl:461
> movq	%r15, %rsi
> callq	*%rax
> movq	%rax, %rbx
> ; │││└└
> ; │││┌ @ broadcast.jl:913 within `copyto!` @ broadcast.jl:949
> ; ││││┌ @ abstractarray.jl:95 within `axes`
> ; │││││┌ @ array.jl:149 within `size`
> movq	8(%rax), %rax
> ; ││││└└
> ; ││││┌ @ tuple.jl:458 within `==`
> ; │││││┌ @ tuple.jl:462 within `_eq`
> ; ││││││┌ @ range.jl:1106 within `==` @ promotion.jl:477
> cmpq	%r15, %rax
> ; ││││└└└
> jne	.LBB0_9
> # %bb.1: # %L23
> movabsq	$9223372036854775806, %rax # imm = 0x7FFFFFFFFFFFFFFE
> ; ││└└
> ; ││┌ @ broadcast.jl:281 within `instantiate`
> ; │││┌ @ broadcast.jl:499 within `combine_axes`
> ; ││││┌ @ range.jl:688 within `axes`
> ; │││││┌ @ range.jl:455 within `oneto`
> ; ││││││┌ @ range.jl:453 within `OneTo` @ range.jl:440
> ; │││││││┌ @ promotion.jl:488 within `max`
> ; ││││││││┌ @ essentials.jl:556 within `ifelse`
> cmpq	%rax, %r13
> ; ││└└└└└└└
> ; ││┌ @ broadcast.jl:885 within `copy`
> ; │││┌ @ broadcast.jl:913 within `copyto!` @ broadcast.jl:960
> ; ││││┌ @ simdloop.jl:72 within `macro expansion`
> ja	.LBB0_8
> # %bb.2: # %L23
> testq	%r15, %r15
> jle	.LBB0_8
> # %bb.3: # %L43.lr.ph
> movq	%rbp, %r13
> xorl	%ebp, %ebp
> ; ││││└
> ; ││││ @ broadcast.jl:913 within `copyto!` @ broadcast.jl:957
> ; ││││┌ @ broadcast.jl:940 within `preprocess`
> ; │││││┌ @ broadcast.jl:943 within `preprocess_args`
> ; ││││││┌ @ broadcast.jl:941 within `preprocess`
> ; │││││││┌ @ broadcast.jl:637 within `extrude`
> ; ││││││││┌ @ broadcast.jl:586 within `newindexer`
> ; │││││││││┌ @ broadcast.jl:587 within `shapeindexer`
> ; ││││││││││┌ @ broadcast.jl:592 within `_newindexer`
> ; │││││││││││┌ @ operators.jl:269 within `!=`
> ; ││││││││││││┌ @ promotion.jl:477 within `==`
> cmpq	%r13, %r12
> ; ││││└└└└└└└└└
> ; ││││ @ broadcast.jl:913 within `copyto!` @ broadcast.jl:960
> ; ││││┌ @ simdloop.jl:75 within `macro expansion`
> jne	.LBB0_4
> # %bb.6: # %L43.us.preheader
> movabsq	$j_power_by_squaring_63, %r13
> .p2align	4, 0x90
> .LBB0_7: # %L43.us
> # =>This Inner Loop Header: Depth=1
> movq	%rbx, 16(%rsp)
> ; │││││ @ simdloop.jl:77 within `macro expansion` @ broadcast.jl:961
> ; │││││┌ @ broadcast.jl:597 within `getindex`
> ; ││││││┌ @ broadcast.jl:643 within `_broadcast_getindex`
> ; │││││││┌ @ broadcast.jl:670 within `_broadcast_getindex_evalf`
> ; ││││││││┌ @ intfuncs.jl:297 within `^`
> movq	%r12, %rdi
> movq	%r14, %rsi
> callq	*%r13
> ; │││││└└└└
> ; │││││┌ @ array.jl:959 within `setindex!`
> movq	(%rbx), %rcx
> movq	%rax, (%rcx,%rbp,8)
> ; │││││└
> ; │││││ @ simdloop.jl:78 within `macro expansion`
> ; │││││┌ @ int.jl:87 within `+`
> incq	%rbp
> ; │││││└
> ; │││││ @ simdloop.jl:75 within `macro expansion`
> ; │││││┌ @ int.jl:83 within `<`
> cmpq	%rbp, %r15
> ; │││││└
> jne	.LBB0_7
> jmp	.LBB0_8
> .LBB0_4: # %L43.preheader
> movabsq	$j_power_by_squaring_63, %r12
> .p2align	4, 0x90
> .LBB0_5: # %L43
> # =>This Inner Loop Header: Depth=1
> ; │││││ @ simdloop.jl:77 within `macro expansion` @ broadcast.jl:961
> ; │││││┌ @ broadcast.jl:597 within `getindex`
> ; ││││││┌ @ broadcast.jl:642 within `_broadcast_getindex`
> ; │││││││┌ @ broadcast.jl:666 within `_getindex`
> ; ││││││││┌ @ broadcast.jl:636 within `_broadcast_getindex`
> ; │││││││││┌ @ range.jl:901 within `getindex`
> ; ││││││││││┌ @ int.jl:87 within `+`
> movq	%r13, %rdi
> addq	%rbp, %rdi
> movq	%rbx, 16(%rsp)
> ; │││││││└└└└
> ; │││││││ @ broadcast.jl:643 within `_broadcast_getindex`
> ; │││││││┌ @ broadcast.jl:670 within `_broadcast_getindex_evalf`
> ; ││││││││┌ @ intfuncs.jl:297 within `^`
> movq	%r14, %rsi
> callq	*%r12
> ; │││││└└└└
> ; │││││┌ @ array.jl:959 within `setindex!`
> movq	(%rbx), %rcx
> movq	%rax, (%rcx,%rbp,8)
> ; │││││└
> ; │││││ @ simdloop.jl:78 within `macro expansion`
> ; │││││┌ @ int.jl:87 within `+`
> incq	%rbp
> ; │││││└
> ; │││││ @ simdloop.jl:75 within `macro expansion`
> ; │││││┌ @ int.jl:83 within `<`
> cmpq	%rbp, %r15
> ; │││││└
> jne	.LBB0_5
> .LBB0_8: # %L110
> movq	8(%rsp), %rax
> movq	32(%rsp), %rcx # 8-byte Reload
> movq	%rax, (%rcx)
> ; │└└└└
> movq	%rbx, %rax
> addq	$56, %rsp
> .cfi_def_cfa_offset 56
> popq	%rbx
> .cfi_def_cfa_offset 48
> popq	%r12
> .cfi_def_cfa_offset 40
> popq	%r13
> .cfi_def_cfa_offset 32
> popq	%r14
> .cfi_def_cfa_offset 24
> popq	%r15
> .cfi_def_cfa_offset 16
> popq	%rbp
> .cfi_def_cfa_offset 8
> retq
> .LBB0_9: # %L99
> ; │┌ @ broadcast.jl:860 within `materialize`
> ; ││┌ @ broadcast.jl:885 within `copy`
> ; │││┌ @ broadcast.jl:913 within `copyto!` @ broadcast.jl:949
> ; ││││┌ @ abstractarray.jl:95 within `axes`
> ; │││││┌ @ tuple.jl:273 within `map`
> ; ││││││┌ @ range.jl:455 within `oneto`
> ; │││││││┌ @ range.jl:453 within `OneTo` @ range.jl:440
> .cfi_def_cfa_offset 112
> movq	%rax, 40(%rsp)
> ; ││││└└└└
> movabsq	$j_throwdm_67, %rax
> leaq	40(%rsp), %rdi
> leaq	48(%rsp), %rsi
> callq	*%rax
> ud2
> .Lfunc_end0:
> .size	"julia_##dotfunction#312#3_61", .Lfunc_end0-"julia_##dotfunction#312#3_61"
> .cfi_endproc
> ; └└└└
> # -- End function
> .section	".note.GNU-stack","",@progbits
> 
> ```

That being said, wrapping the expression in a function restores performance for me, so may have to do with inlining heuristics or timing at the top level & global scope (which should be avoided anyway):

```julia
julia> f() = (1:10^9).^2
f (generic function with 1 method)

julia> @time f();
  3.127988 seconds (2 allocations: 7.451 GiB, 0.22% gc time)

```

---

<div class="post-metadata">

**Author:** ![mindaslab](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mindaslab/32/12673_2.png) [@mindaslab](https://discourse.julialang.org/u/mindaslab)\
**Post date:** [June 2, 2022, 4:31pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/14 "2022-06-02T16:31:05Z")

</div>

Hello All,

I have rerun it and added with version info so that it might be useful for some one.

For 1.8:

```julia
julia> versioninfo(;verbose=true)
Julia Version 1.8.0-rc1
Commit 6368fdc6565 (2022-05-27 18:33 UTC)
Platform Info:
  OS: macOS (arm64-apple-darwin21.3.0)
  uname: Darwin 21.5.0 Darwin Kernel Version 21.5.0: Tue Apr 26 21:08:29 PDT 2022; root:xnu-8020.121.3~4/RELEASE_ARM64_T8101 arm64 arm
  CPU: Apple M1:
              speed user nice sys idle irq
       #1 24 MHz 268397 s 0 s 226552 s 2012133 s 0 s
       #2 24 MHz 252151 s 0 s 206049 s 2048840 s 0 s
       #3 24 MHz 216621 s 0 s 173810 s 2116610 s 0 s
       #4 24 MHz 193609 s 0 s 150167 s 2163265 s 0 s
       #5 24 MHz 249916 s 0 s 90322 s 2166801 s 0 s
       #6 24 MHz 193540 s 0 s 47919 s 2265581 s 0 s
       #7 24 MHz 147989 s 0 s 32894 s 2326158 s 0 s
       #8 24 MHz 111387 s 0 s 24122 s 2371532 s 0 s
  Memory: 16.0 GB (4686.4375 MB free)
  Uptime: 713907.0 sec
  Load Avg: 2.3203125 1.94775390625 1.94873046875
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-13.0.1 (ORCJIT, apple-m1)
  Threads: 1 on 4 virtual cores

julia> @time (1:10^9).^2;
 11.966374 seconds (2 allocations: 7.451 GiB, 0.03% gc time)

```

For 1.7:

```julia
julia> versioninfo(;verbose=true)
Julia Version 1.7.2
Commit bf53498635 (2022-02-06 15:21 UTC)
Platform Info:
  OS: macOS (arm64-apple-darwin21.2.0)
  uname: Darwin 21.5.0 Darwin Kernel Version 21.5.0: Tue Apr 26 21:08:29 PDT 2022; root:xnu-8020.121.3~4/RELEASE_ARM64_T8101 arm64 arm
  CPU: Apple M1:
              speed user nice sys idle irq
       #1 24 MHz 268968 s 0 s 227072 s 2015937 s 0 s
       #2 24 MHz 252696 s 0 s 206528 s 2052712 s 0 s
       #3 24 MHz 217099 s 0 s 174210 s 2120628 s 0 s
       #4 24 MHz 194038 s 0 s 150514 s 2167386 s 0 s
       #5 24 MHz 250359 s 0 s 90518 s 2171058 s 0 s
       #6 24 MHz 193898 s 0 s 48033 s 2270005 s 0 s
       #7 24 MHz 148184 s 0 s 32955 s 2330798 s 0 s
       #8 24 MHz 111516 s 0 s 24166 s 2376257 s 0 s

  Memory: 16.0 GB (4438.984375 MB free)
  Uptime: 714396.0 sec
  Load Avg: 3.8828125 2.6142578125 2.22265625
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-12.0.1 (ORCJIT, cyclone)

julia> @time (1:10^9).^2;
  2.412986 seconds (2 allocations: 7.451 GiB, 0.37% gc time)

```

---

<div class="post-metadata">

**Author:** ![Sukera](https://avatars.discourse-cdn.com/v4/letter/s/ce7236/32.png) [@Sukera](https://discourse.julialang.org/u/Sukera)\
**Post date:** [June 2, 2022, 4:32pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/15 "2022-06-02T16:32:51Z")

</div>

> [@mindaslab](#):
>
> `Memory: 16.0 GB (4686.4375 MB free)`

Well, irrespective of the slowdown at the top level being a thing, you’re certainly hitting SWAP, and with that disk I/O. You’re allocating an array larger than your remaining free RAM. I’d suggest closing some background tasks and rerunning it.

Either way, can you please also run

```julia
f() = (1:10^9).^2
@time f();

```

?

---

<div class="post-metadata">

**Author:** ![mindaslab](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mindaslab/32/12673_2.png) [@mindaslab](https://discourse.julialang.org/u/mindaslab)\
**Post date:** [June 2, 2022, 4:42pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/16 "2022-06-02T16:42:33Z")

</div>

> [@Sukera](#):
>
> ```julia
> @time f();
> 
> ```

It’s just 1.42 seconds! Wow! For Julia 1.8:

```julia
julia> f() = (1:10^9).^2
f (generic function with 1 method)

julia> @time f();
  1.415760 seconds (2 allocations: 7.451 GiB, 0.32% gc time)

```

And 1.40 for Julia 1.7.2:

```julia
julia> f() = (1:10^9).^2
f (generic function with 1 method)

julia> @time f();
  1.404488 seconds (2 allocations: 7.451 GiB, 0.32% gc time)

```

Can any one explain why wrapping in function makes such a huge difference?

---

<div class="post-metadata">

**Author:** ![Sukera](https://avatars.discourse-cdn.com/v4/letter/s/ce7236/32.png) [@Sukera](https://discourse.julialang.org/u/Sukera)\
**Post date:** [June 2, 2022, 4:49pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/17 "2022-06-02T16:49:01Z")

</div>

> [@mindaslab](#):
>
> It’s just 1.42 seconds! Wow!

That’s what I like to see!

> [@mindaslab](#):
>
> Can any one explain why wrapping in function makes such a huge difference?

We can take a look at what `@time` is actually doing, with `@macroexpand`:

```julia
julia> @macroexpand @time (1:10^9).^2
quote
    begin
        $(Expr(:meta, :force_compile))
        local var"#8#stats" = Base.gc_num()
        local var"#10#elapsedtime" = Base.time_ns()
        Base.cumulative_compile_timing(true)
        local var"#11#compile_elapsedtimes" = Base.cumulative_compile_time_ns()
        local var"#9#val" = $(Expr(:tryfinally, :((1:10 ^ 9) .^ 2), quote
    var"#10#elapsedtime" = Base.time_ns() - var"#10#elapsedtime"
    Base.cumulative_compile_timing(false)
    var"#11#compile_elapsedtimes" = Base.cumulative_compile_time_ns() .- var"#11#compile_elapsedtimes"
end))
        local var"#12#diff" = Base.GC_Diff(Base.gc_num(), var"#8#stats")
        local var"#13#_msg" = Base.nothing
        local var"#14#has_msg" = !(Base.isnothing(var"#13#_msg"))
        var"#14#has_msg" && Base.print(var"#13#_msg", ": ")
        Base.time_print(var"#10#elapsedtime", (var"#12#diff").allocd, (var"#12#diff").total_time, Base.gc_alloc_count(var"#12#diff"), Base.first(var"#11#compile_elapsedtimes"), Base.last(var"#11#compile_elapsedtimes"), true, !var"#14#has_msg")
        var"#9#val"
    end
end

```

(I’ve removed all the comments signifying where the macro was defined.)

`@time` does nothing more than wrap your code (see the `loval var"#9#val" = ..` thing) and calculates how long it took to run. This has the sideeffect of running your code exactly as you wrote it - meaning in this case, it’s all run in global scope. Global scope does not allow for the same optimizations that can be done in a function, hence there will always be a performance difference between the two. Since the slowdown _does not_ appear in a function, I’m inclined to conclude that this is not a bug with julia 1.8, but rather a benchmarking artifact due to benchmarking in global scope (which is a bad idea, as you’ve noticed).

This is also mentioned in the Performance tips:

> [Performance critical code should be inside a function](https://docs.julialang.org/en/v1/manual/performance-tips/#Performance-critical-code-should-be-inside-a-function)
> 
> Any code that is performance critical should be inside a function. Code inside functions tends to run much faster than top level code, due to how Julia’s compiler works.

---

<div class="post-metadata">

**Author:** ![yangcht](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/yangcht/32/4170_2.png) [@yangcht](https://discourse.julialang.org/u/yangcht)\
**Post date:** [July 22, 2022, 9:04am UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/18 "2022-07-22T09:04:45Z")

</div>

![Screenshot 2022-07-22 at 11.04.30](https://global.discourse-cdn.com/julialang/original/3X/c/9/c976b401e718c794339eb75090691b5a1afff97f.png)

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**Author:** ![Freya\_the\_Goddess](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/freya_the_goddess/32/36835_2.png) [@Freya\_the\_Goddess](https://discourse.julialang.org/u/Freya_the_Goddess)\
**Post date:** [July 22, 2022, 9:54am UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/19 "2022-07-22T09:54:48Z")

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My computer/laptop is slow.

What makes it faster? Processor or RAM?

 ![Capture d’écran_2022-07-22_16-59-38](https://global.discourse-cdn.com/julialang/original/3X/0/6/061348840b832d434896e0f1f9468ae584f1435f.png)

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<div class="post-metadata">

**Author:** ![tim.holy](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tim.holy/32/52_2.png) [@tim.holy](https://discourse.julialang.org/u/tim.holy)\
**Post date:** [July 22, 2022, 12:03pm UTC](https://discourse.julialang.org/t/shouldnt-1-8-0-be-faster-than-julia-1-7/82143/20 "2022-07-22T12:03:40Z")

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Can I recommend that anyone who is trying this change it to

```julia
using BenchmarkTools
f() = (1:10^6).^2
@btime f();

```

As Matt says, there’s really no point allocating a 7GB RAM array as part of a benchmark. Your results will entirely depend on details of your hardware and what you have loaded concurrently. This really is meaningless and no one should draw conclusions from the other variants here.

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