diff options
Diffstat (limited to 'src/test/codegen/swap-small-types.rs')
-rw-r--r-- | src/test/codegen/swap-small-types.rs | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/src/test/codegen/swap-small-types.rs b/src/test/codegen/swap-small-types.rs new file mode 100644 index 000000000..03e2a2327 --- /dev/null +++ b/src/test/codegen/swap-small-types.rs @@ -0,0 +1,63 @@ +// compile-flags: -O +// only-x86_64 +// ignore-debug: the debug assertions get in the way + +#![crate_type = "lib"] + +use std::mem::swap; + +type RGB48 = [u16; 3]; + +// CHECK-LABEL: @swap_rgb48 +#[no_mangle] +pub fn swap_rgb48(x: &mut RGB48, y: &mut RGB48) { + // FIXME MIR inlining messes up LLVM optimizations. +// WOULD-CHECK-NOT: alloca +// WOULD-CHECK: load i48 +// WOULD-CHECK: store i48 + swap(x, y) +} + +// LLVM doesn't vectorize a loop over 3-byte elements, +// so we chunk it down to bytes and loop over those instead. +type RGB24 = [u8; 3]; + +// CHECK-LABEL: @swap_rgb24_slices +#[no_mangle] +pub fn swap_rgb24_slices(x: &mut [RGB24], y: &mut [RGB24]) { +// CHECK-NOT: alloca +// CHECK: load <{{[0-9]+}} x i8> +// CHECK: store <{{[0-9]+}} x i8> + if x.len() == y.len() { + x.swap_with_slice(y); + } +} + +// This one has a power-of-two size, so we iterate over it directly +type RGBA32 = [u8; 4]; + +// CHECK-LABEL: @swap_rgba32_slices +#[no_mangle] +pub fn swap_rgba32_slices(x: &mut [RGBA32], y: &mut [RGBA32]) { +// CHECK-NOT: alloca +// CHECK: load <{{[0-9]+}} x i32> +// CHECK: store <{{[0-9]+}} x i32> + if x.len() == y.len() { + x.swap_with_slice(y); + } +} + +// Strings have a non-power-of-two size, but have pointer alignment, +// so we swap usizes instead of dropping all the way down to bytes. +const _: () = assert!(!std::mem::size_of::<String>().is_power_of_two()); + +// CHECK-LABEL: @swap_string_slices +#[no_mangle] +pub fn swap_string_slices(x: &mut [String], y: &mut [String]) { +// CHECK-NOT: alloca +// CHECK: load <{{[0-9]+}} x i64> +// CHECK: store <{{[0-9]+}} x i64> + if x.len() == y.len() { + x.swap_with_slice(y); + } +} |