rustc_target: Add more RISC-V vector-related features and use zvl*b target features in vector ABI check

[taiki-e]

Currently, we have only unstable v target feature, but RISC-V have more vector-related extensions. The first commit of this PR adds them to unstable riscv_target_feature.

• unaligned-vector-mem: Has reasonably performant unaligned vector
  • LLVM definition
  • Similar to currently unstable unaligned-scalar-mem target feature, but for vector instructions.
• zvfh: Vector Extension for Half-Precision Floating-Point
  • ISA Manual
  • LLVM definition
  • This implies zvfhmin and zfhmin
• zvfhmin: Vector Extension for Minimal Half-Precision Floating-Point
  • ISA Manual
  • LLVM definition
  • This implies zve32f
• zve32x, zve32f, zve64x, zve64f, zve64d: Vector Extensions for Embedded Processors
  • ISA Manual
  • LLVM definitions
  • zve32x implies zvl32b
  • zve32f implies zve32x and f
  • zve64x implies zve32x and zvl64b
  • zve64f implies zve32f and zve64x
  • zve64d implies zve64f and d
  • v implies zve64d
• zvl*b: Minimum Vector Length Standard Extensions
  • ISA Manual
  • LLVM definitions
  • zvl{N}b implies zvl{N>>1}b
  • v implies zvl128b
• Vector Cryptography and Bit-manipulation Extensions
  • ISA Manual
  • LLVM definitions
  • zvkb: Vector Bit-manipulation used in Cryptography
    • This implies zve32x
  • zvbb: Vector basic bit-manipulation instructions
    • This implies zvkb
  • zvbc: Vector Carryless Multiplication
    • This implies zve64x
  • zvkg: Vector GCM instructions for Cryptography
    • This implies zve32x
  • zvkned: Vector AES Encryption & Decryption (Single Round)
    • This implies zve32x
  • zvknha: Vector SHA-2 (SHA-256 only))
    • This implies zve32x
  • zvknhb: Vector SHA-2 (SHA-256 and SHA-512)
    • This implies zve64x
    • This is superset of zvknha, but doesn't imply that feature at least in LLVM
  • zvksed: SM4 Block Cipher Instructions
    • This implies zve32x
  • zvksh: SM3 Hash Function Instructions
    • This implies zve32x
  • zvkt: Vector Data-Independent Execution Latency
    • Similar to already stabilized scalar cryptography extension zkt.
  • zvkn: Shorthand for 'Zvkned', 'Zvknhb', 'Zvkb', and 'Zvkt'
    • Similar to already stabilized scalar cryptography extension zkn.
  • zvknc: Shorthand for 'Zvkn' and 'Zvbc'
  • zvkng: shorthand for 'Zvkn' and 'Zvkg'
  • zvks: shorthand for 'Zvksed', 'Zvksh', 'Zvkb', and 'Zvkt'
    • Similar to already stabilized scalar cryptography extension zks.
  • zvksc: shorthand for 'Zvks' and 'Zvbc'
  • zvksg: shorthand for 'Zvks' and 'Zvkg'

Also, our vector ABI check wants zvl*b target features, the second commit of this PR updates vector ABI check to use them.

rust/compiler/rustc_target/src/target_features.rs

Lines 707 to 708 in 4e2b096

	const RISCV_FEATURES_FOR_CORRECT_VECTOR_ABI: &'static [(u64, &'static str)] =
	&[/*(64, "zvl64b"), */ (128, "v")];

---

r? @Amanieu

@rustbot label +O-riscv +A-target-feature

[a4lg]

Second this.
Note: if #138823 is merged, zve32x should have dependency to zicsr.

[Amanieu]

@bors r+

[bors]

📌 Commit 8a6f96a has been approved by Amanieu

It is now in the queue for this repository.

[bors]

⌛ Testing commit 8a6f96a with merge 85f518e...

[bors]

☀️ Test successful - checks-actions
Approved by: Amanieu
Pushing 85f518e to master...

[github-actions]

What is this?

This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.

Comparing 2196aff (parent) -> 85f518e (this PR)

Test differences

No test diffs found

Job duration changes

1. dist-apple-various: 5427.7s -> 9487.7s (74.8%)
2. x86_64-apple-1: 7033.8s -> 7703.2s (9.5%)
3. dist-riscv64-linux: 4805.3s -> 5123.0s (6.6%)
4. aarch64-gnu-debug: 5928.0s -> 6319.5s (6.6%)
5. aarch64-apple: 3708.3s -> 3906.9s (5.4%)
6. dist-aarch64-apple: 4946.3s -> 5199.0s (5.1%)
7. i686-mingw-3: 8258.8s -> 8630.5s (4.5%)
8. dist-aarch64-linux: 7372.3s -> 7658.6s (3.9%)
9. dist-x86_64-apple: 6913.5s -> 7176.4s (3.8%)
10. i686-mingw-1: 7153.9s -> 7400.2s (3.4%)

How to interpret the job duration changes?

Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.

[rust-timer]

Finished benchmarking commit (85f518e): comparison URL.

Overall result: ❌ regressions - no action needed

@rustbot label: -perf-regression

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.4%	[0.3%, 0.5%]	5
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary -2.5%, secondary 2.3%)

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)	-	-	0
Regressions ❌ (secondary)	3.3%	[0.8%, 4.3%]	4
Improvements ✅ (primary)	-2.5%	[-2.5%, -2.5%]	1
Improvements ✅ (secondary)	-2.1%	[-2.1%, -2.1%]	1
All ❌✅ (primary)	-2.5%	[-2.5%, -2.5%]	1

Cycles

Results (secondary 5.5%)

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)	-	-	0
Regressions ❌ (secondary)	5.5%	[2.6%, 8.4%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 777.614s -> 776.851s (-0.10%)
Artifact size: 365.95 MiB -> 365.87 MiB (-0.02%)