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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:18:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:18:58 +0000 |
commit | a4b7ed7a42c716ab9f05e351f003d589124fd55d (patch) | |
tree | b620cd3f223850b28716e474e80c58059dca5dd4 /tests/codegen/vec-in-place.rs | |
parent | Adding upstream version 1.67.1+dfsg1. (diff) | |
download | rustc-a4b7ed7a42c716ab9f05e351f003d589124fd55d.tar.xz rustc-a4b7ed7a42c716ab9f05e351f003d589124fd55d.zip |
Adding upstream version 1.68.2+dfsg1.upstream/1.68.2+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tests/codegen/vec-in-place.rs')
-rw-r--r-- | tests/codegen/vec-in-place.rs | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/tests/codegen/vec-in-place.rs b/tests/codegen/vec-in-place.rs new file mode 100644 index 000000000..5df366905 --- /dev/null +++ b/tests/codegen/vec-in-place.rs @@ -0,0 +1,74 @@ +// min-llvm-version: 14.0 +// ignore-debug: the debug assertions get in the way +// compile-flags: -O -Z merge-functions=disabled +#![crate_type = "lib"] + +// Ensure that trivial casts of vec elements are O(1) + +pub struct Wrapper<T>(T); + +#[repr(C)] +pub struct Foo { + a: u64, + b: u64, + c: u64, + d: u64, +} + +// Going from an aggregate struct to another type currently requires Copy to +// enable the TrustedRandomAccess specialization. Without it optimizations do not yet +// reliably recognize the loops as noop for repr(C) or non-Copy structs. +#[derive(Copy, Clone)] +pub struct Bar { + a: u64, + b: u64, + c: u64, + d: u64, +} + +// CHECK-LABEL: @vec_iterator_cast_primitive +#[no_mangle] +pub fn vec_iterator_cast_primitive(vec: Vec<i8>) -> Vec<u8> { + // CHECK-NOT: loop + // CHECK-NOT: call + vec.into_iter().map(|e| e as u8).collect() +} + +// CHECK-LABEL: @vec_iterator_cast_wrapper +#[no_mangle] +pub fn vec_iterator_cast_wrapper(vec: Vec<u8>) -> Vec<Wrapper<u8>> { + // CHECK-NOT: loop + // CHECK-NOT: call + vec.into_iter().map(|e| Wrapper(e)).collect() +} + +// CHECK-LABEL: @vec_iterator_cast_unwrap +#[no_mangle] +pub fn vec_iterator_cast_unwrap(vec: Vec<Wrapper<u8>>) -> Vec<u8> { + // CHECK-NOT: loop + // CHECK-NOT: call + vec.into_iter().map(|e| e.0).collect() +} + +// CHECK-LABEL: @vec_iterator_cast_aggregate +#[no_mangle] +pub fn vec_iterator_cast_aggregate(vec: Vec<[u64; 4]>) -> Vec<Foo> { + // FIXME These checks should be the same as other functions. + // CHECK-NOT: @__rust_alloc + // CHECK-NOT: @__rust_alloc + vec.into_iter().map(|e| unsafe { std::mem::transmute(e) }).collect() +} + +// CHECK-LABEL: @vec_iterator_cast_deaggregate +#[no_mangle] +pub fn vec_iterator_cast_deaggregate(vec: Vec<Bar>) -> Vec<[u64; 4]> { + // FIXME These checks should be the same as other functions. + // CHECK-NOT: @__rust_alloc + // CHECK-NOT: @__rust_alloc + + // Safety: For the purpose of this test we assume that Bar layout matches [u64; 4]. + // This currently is not guaranteed for repr(Rust) types, but it happens to work here and + // the UCG may add additional guarantees for homogenous types in the future that would make this + // correct. + vec.into_iter().map(|e| unsafe { std::mem::transmute(e) }).collect() +} |