rust/tests/codegen/slice-is-ascii.rs

//@ only-x86_64
//@ compile-flags: -C opt-level=3 -C target-cpu=x86-64
#![crate_type = "lib"]

/// Check that the fast-path of `is_ascii` uses a `pmovmskb` instruction.
/// Platforms lacking an equivalent instruction use other techniques for
/// optimizing `is_ascii`.
// CHECK-LABEL: @is_ascii_autovectorized
#[no_mangle]
pub fn is_ascii_autovectorized(s: &[u8]) -> bool {
    // CHECK: load <32 x i8>
    // CHECK-NEXT: icmp slt <32 x i8>
    // CHECK-NEXT: bitcast <32 x i1>
    // CHECK-NEXT: icmp eq i32
    s.is_ascii()
}
Add `is_ascii` function optimized for x86-64 for [u8] The new `is_ascii` function is optimized to use the `pmovmskb` vector instruction which tests the high bit in a lane. This corresponds to the same check of whether a byte is ASCII so ASCII validity checking can be vectorized. This instruction does not exist on other platforms so it is likely to regress performance and is gated to all(target_arch = "x86_64", target_feature = "sse2"). Add codegen test Remove crate::mem import for functions included in the prelude 2024-09-26 23:39:14 +00:00			`//@ only-x86_64`
Use explicit cpu in some asm and codegen tests. Some tests expect to be compiled for a specific CPU or require certain target features to be present (or absent). These tests work fine with default CPUs but fail in downstream builds for RHEL and Fedora, where we use non-default CPUs such as z13 on s390x, pwr9 on ppc64le, or x86-64-v2/x86-64-v3 on x86_64. 2025-03-19 18:29:08 +00:00			`//@ compile-flags: -C opt-level=3 -C target-cpu=x86-64`
Add `is_ascii` function optimized for x86-64 for [u8] The new `is_ascii` function is optimized to use the `pmovmskb` vector instruction which tests the high bit in a lane. This corresponds to the same check of whether a byte is ASCII so ASCII validity checking can be vectorized. This instruction does not exist on other platforms so it is likely to regress performance and is gated to all(target_arch = "x86_64", target_feature = "sse2"). Add codegen test Remove crate::mem import for functions included in the prelude 2024-09-26 23:39:14 +00:00			`#![crate_type = "lib"]`

			/// Check that the fast-path of `is_ascii` uses a `pmovmskb` instruction.
			`/// Platforms lacking an equivalent instruction use other techniques for`
			/// optimizing `is_ascii`.
			`// CHECK-LABEL: @is_ascii_autovectorized`
			`#[no_mangle]`
			`pub fn is_ascii_autovectorized(s: &[u8]) -> bool {`
			`// CHECK: load <32 x i8>`
			`// CHECK-NEXT: icmp slt <32 x i8>`
			`// CHECK-NEXT: bitcast <32 x i1>`
			`// CHECK-NEXT: icmp eq i32`
			`s.is_ascii()`
			`}`