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| author | Guillaume Gomez <guillaume1.gomez@gmail.com> | 2025-07-21 14:34:12 +0200 |
|---|---|---|
| committer | Guillaume Gomez <guillaume1.gomez@gmail.com> | 2025-07-22 14:28:48 +0200 |
| commit | a27f3e3fd1e4d16160f8885b6b06665b5319f56c (patch) | |
| tree | b033935392cbadf6f85d2dbddf433a88e323aeeb /tests/codegen-llvm/dst-vtable-align-nonzero.rs | |
| parent | ed93c1783b404d728d4809973a0550eb33cd293f (diff) | |
| download | rust-a27f3e3fd1e4d16160f8885b6b06665b5319f56c.tar.gz rust-a27f3e3fd1e4d16160f8885b6b06665b5319f56c.zip | |
Rename `tests/codegen` into `tests/codegen-llvm`
Diffstat (limited to 'tests/codegen-llvm/dst-vtable-align-nonzero.rs')
| -rw-r--r-- | tests/codegen-llvm/dst-vtable-align-nonzero.rs | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/tests/codegen-llvm/dst-vtable-align-nonzero.rs b/tests/codegen-llvm/dst-vtable-align-nonzero.rs new file mode 100644 index 00000000000..1404bd64f50 --- /dev/null +++ b/tests/codegen-llvm/dst-vtable-align-nonzero.rs @@ -0,0 +1,67 @@ +//@ compile-flags: -Copt-level=3 -Z merge-functions=disabled + +#![crate_type = "lib"] +#![feature(core_intrinsics)] + +// This test checks that we annotate alignment loads from vtables with nonzero range metadata, +// and that this allows LLVM to eliminate redundant `align >= 1` checks. + +pub trait Trait { + fn f(&self); +} + +pub struct WrapperWithAlign1<T: ?Sized> { + x: u8, + y: T, +} + +pub struct WrapperWithAlign2<T: ?Sized> { + x: u16, + y: T, +} + +pub struct Struct<W: ?Sized> { + _field: i8, + dst: W, +} + +// CHECK-LABEL: @eliminates_runtime_check_when_align_1 +#[no_mangle] +pub fn eliminates_runtime_check_when_align_1( + x: &Struct<WrapperWithAlign1<dyn Trait>>, +) -> &WrapperWithAlign1<dyn Trait> { + // CHECK: load [[USIZE:i[0-9]+]], {{.+}} !range [[RANGE_META:![0-9]+]] + // CHECK-NOT: llvm.umax + // CHECK-NOT: icmp + // CHECK-NOT: select + // CHECK: ret + &x.dst +} + +// CHECK-LABEL: @does_not_eliminate_runtime_check_when_align_2 +#[no_mangle] +pub fn does_not_eliminate_runtime_check_when_align_2( + x: &Struct<WrapperWithAlign2<dyn Trait>>, +) -> &WrapperWithAlign2<dyn Trait> { + // CHECK: [[X0:%[0-9]+]] = load [[USIZE]], {{.+}} !range [[RANGE_META]] + // CHECK: {{icmp|llvm.umax}} + // CHECK: ret + &x.dst +} + +// CHECK-LABEL: @align_load_from_align_of_val +#[no_mangle] +pub fn align_load_from_align_of_val(x: &dyn Trait) -> usize { + // CHECK: {{%[0-9]+}} = load [[USIZE]], {{.+}} !range [[RANGE_META]] + core::mem::align_of_val(x) +} + +// CHECK-LABEL: @align_load_from_vtable_align_intrinsic +#[no_mangle] +pub unsafe fn align_load_from_vtable_align_intrinsic(x: &dyn Trait) -> usize { + let (data, vtable): (*const (), *const ()) = core::mem::transmute(x); + // CHECK: {{%[0-9]+}} = load [[USIZE]], {{.+}} !range [[RANGE_META]] + core::intrinsics::vtable_align(vtable) +} + +// CHECK: [[RANGE_META]] = !{[[USIZE]] 1, [[USIZE]] 0} |
