Add a Debug impl and some basic functions to f16 and f128

[tgross35]

compiler_builtins uses some convenience functions like is_nan and is_sign_positive. Add these, as well as a temporary implementation for Debug that prints the bit representation.

[rustbot]

r? @jhpratt

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[tgross35]

In #122470 I forgot to include a Debug implementation which is needed for compiler_builtins work, and it looks like some simple methods are also needed.

Unfortunately this won't pass CI until mangling support is added.

@rustbot label -T-libs +T-libs-api +S-blocked +F-f16_and_f128
r? @Amanieu

[GuillaumeGomez]

It's not the correct version, right?

[tgross35]

I have just been using the same gate as the traits on f32 and f64 for now, since most of the impl macros don't have a way to specify the gate. I think that when this is closer to stabilization I will change the macros and add a separate gate, but for now I don't think it gains much to not just match the other floats.

[tgross35]

Convenient, looks like making everything inline means we don't get blocked by the mangling test.

@rustbot ready

[Amanieu]

@bors r+

[bors]

📌 Commit 5159ecd has been approved by Amanieu

It is now in the queue for this repository.

[bors]

⌛ Testing commit 5159ecd with merge 7bdae13...

[bors]

☀️ Test successful - checks-actions
Approved by: Amanieu
Pushing 7bdae13 to master...

[rust-timer]

Finished benchmarking commit (7bdae13): comparison URL.

Overall result: ❌ regressions - no action needed

@rustbot label: -perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	0.3%	[0.3%, 0.3%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.3%	[0.3%, 0.3%]	1

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	2.6%	[2.6%, 2.6%]	1
Regressions ❌ (secondary)	3.3%	[3.3%, 3.3%]	1
Improvements ✅ (primary)	-2.2%	[-2.2%, -2.2%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.2%	[-2.2%, 2.6%]	2

Cycles

This benchmark run did not return any relevant results for this metric.

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 676.395s -> 677.095s (0.10%)
Artifact size: 316.00 MiB -> 316.00 MiB (-0.00%)