From cc7d8014d720ac800f868a0b7ec854f4a5036e3f Mon Sep 17 00:00:00 2001 From: Scott McMurray Date: Tue, 9 Nov 2021 21:43:20 -0800 Subject: Specialize array cloning for Copy types Because after PR 86041, the optimizer no longer load-merges at the LLVM IR level, which might be part of the perf loss. (I'll run perf and see if this makes a difference.) Also I added a codegen test so this hopefully won't regress in future -- it passes on stable and with my change here, but not on the 2021-11-09 nightly. --- src/test/codegen/array-clone.rs | 15 +++++++++++++++ 1 file changed, 15 insertions(+) create mode 100644 src/test/codegen/array-clone.rs (limited to 'src/test/codegen/array-clone.rs') diff --git a/src/test/codegen/array-clone.rs b/src/test/codegen/array-clone.rs new file mode 100644 index 00000000000..0d42963bcd2 --- /dev/null +++ b/src/test/codegen/array-clone.rs @@ -0,0 +1,15 @@ +// compile-flags: -O + +#![crate_type = "lib"] + +// CHECK-LABEL: @array_clone +#[no_mangle] +pub fn array_clone(a: &[u8; 2]) -> [u8; 2] { + // CHECK-NOT: getelementptr + // CHECK-NOT: load i8 + // CHECK-NOT: zext + // CHECK-NOT: shl + // CHECK: load i16 + // CHECK-NEXT: ret i16 + a.clone() +} -- cgit 1.4.1-3-g733a5