From f6a57c195519d1e3e1f2f84b5793b2449f6c1625 Mon Sep 17 00:00:00 2001 From: Scott McMurray Date: Wed, 1 Mar 2023 10:57:46 -0800 Subject: Move `Option::as_slice` to an always-sound implementation This approach depends on CSE to not have any branches or selects when the guessed offset is correct -- which it always will be right now -- but to also be *sound* (just less efficient) if the layout algorithms change such that the guess is incorrect. --- tests/codegen/option-as-slice.rs | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) (limited to 'tests/codegen') diff --git a/tests/codegen/option-as-slice.rs b/tests/codegen/option-as-slice.rs index d5077dbf6cc..d735d558374 100644 --- a/tests/codegen/option-as-slice.rs +++ b/tests/codegen/option-as-slice.rs @@ -1,4 +1,4 @@ -// compile-flags: -O +// compile-flags: -O -Z randomize-layout=no // only-x86_64 #![crate_type = "lib"] @@ -12,17 +12,25 @@ use core::option::Option; // CHECK-LABEL: @u64_opt_as_slice #[no_mangle] pub fn u64_opt_as_slice(o: &Option) -> &[u64] { - // CHECK: start: // CHECK-NOT: select - // CHECK: ret + // CHECK-NOT: br + // CHECK-NOT: switch + // CHECK-NOT: icmp o.as_slice() } // CHECK-LABEL: @nonzero_u64_opt_as_slice #[no_mangle] pub fn nonzero_u64_opt_as_slice(o: &Option) -> &[NonZeroU64] { - // CHECK: start: // CHECK-NOT: select - // CHECK: ret + // CHECK-NOT: br + // CHECK-NOT: switch + // CHECK-NOT: icmp + // CHECK: %[[NZ:.+]] = icmp ne i64 %{{.+}}, 0 + // CHECK-NEXT: zext i1 %[[NZ]] to i64 + // CHECK-NOT: select + // CHECK-NOT: br + // CHECK-NOT: switch + // CHECK-NOT: icmp o.as_slice() } -- cgit 1.4.1-3-g733a5