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.

[a4lg]

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