From 335690200ef72899cd675f1ebb65d5d7a17dc29b Mon Sep 17 00:00:00 2001 From: Scott McMurray Date: Sat, 17 Sep 2022 18:54:00 -0700 Subject: [PATCH] Add a codegen test for slice::from_ptr_range --- src/test/codegen/slice_as_from_ptr_range.rs | 23 +++++++++++++++++++++ 1 file changed, 23 insertions(+) create mode 100644 src/test/codegen/slice_as_from_ptr_range.rs diff --git a/src/test/codegen/slice_as_from_ptr_range.rs b/src/test/codegen/slice_as_from_ptr_range.rs new file mode 100644 index 0000000000000..0e3fefd9728df --- /dev/null +++ b/src/test/codegen/slice_as_from_ptr_range.rs @@ -0,0 +1,23 @@ +// compile-flags: -O +// only-64bit (because we're using [ui]size) +// ignore-debug (because the assertions get in the way) +// min-llvm-version: 15.0 (because this is a relatively new instcombine) + +#![crate_type = "lib"] +#![feature(slice_from_ptr_range)] + +// This is intentionally using a non-power-of-two array length, +// as that's where the optimization differences show up + +// CHECK-LABEL: @flatten_via_ptr_range +#[no_mangle] +pub fn flatten_via_ptr_range(slice_of_arrays: &[[i32; 13]]) -> &[i32] { + // CHECK-NOT: lshr + // CHECK-NOT: udiv + // CHECK: mul nuw nsw i64 %{{.+}}, 13 + // CHECK-NOT: lshr + // CHECK-NOT: udiv + let r = slice_of_arrays.as_ptr_range(); + let r = r.start.cast()..r.end.cast(); + unsafe { core::slice::from_ptr_range(r) } +}