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| author | Scott McMurray <scottmcm@users.noreply.github.com> | 2025-04-07 18:12:06 -0700 |
|---|---|---|
| committer | Scott McMurray <scottmcm@users.noreply.github.com> | 2025-04-07 18:12:06 -0700 |
| commit | 502f7f9c241b35d65f4538d28c43e6feca474df2 (patch) | |
| tree | 30af419459c7b7031ab64bf128edb005931399e3 | |
| parent | 51e67e21cf2ca50a431d392a03dcc66377a365cd (diff) | |
| download | rust-502f7f9c241b35d65f4538d28c43e6feca474df2.tar.gz rust-502f7f9c241b35d65f4538d28c43e6feca474df2.zip | |
Address PR feedback
| -rw-r--r-- | compiler/rustc_codegen_ssa/src/mir/operand.rs | 4 | ||||
| -rw-r--r-- | tests/codegen/enum/enum-two-variants-match.rs | 16 |
2 files changed, 19 insertions, 1 deletions
diff --git a/compiler/rustc_codegen_ssa/src/mir/operand.rs b/compiler/rustc_codegen_ssa/src/mir/operand.rs index fca0695f296..eade9e52de9 100644 --- a/compiler/rustc_codegen_ssa/src/mir/operand.rs +++ b/compiler/rustc_codegen_ssa/src/mir/operand.rs @@ -581,7 +581,9 @@ impl<'a, 'tcx, V: CodegenObject> OperandRef<'tcx, V> { ); // In principle we could insert assumes on the possible range of `discr`, but - // currently in LLVM this seems to be a pessimization. + // currently in LLVM this isn't worth it because the original `tag` will + // have either a `range` parameter attribute or `!range` metadata, + // or come from a `transmute` that already `assume`d it. discr } diff --git a/tests/codegen/enum/enum-two-variants-match.rs b/tests/codegen/enum/enum-two-variants-match.rs index 5b6c0e2f8ad..12d9edc4d62 100644 --- a/tests/codegen/enum/enum-two-variants-match.rs +++ b/tests/codegen/enum/enum-two-variants-match.rs @@ -3,6 +3,10 @@ #![crate_type = "lib"] +// This directly tests what we emit for these matches, rather than what happens +// after optimization, so it doesn't need to worry about extra flags on the +// instructions and is less susceptible to being broken on LLVM updates. + // CHECK-LABEL: @option_match #[no_mangle] pub fn option_match(x: Option<i32>) -> u16 { @@ -103,10 +107,22 @@ pub fn option_ordering_match(x: Option<Ordering>) -> char { // CHECK-LABEL: @option_nonzero_match( #[no_mangle] pub fn option_nonzero_match(x: Option<std::num::NonZero<u16>>) -> u16 { + // CHECK: %[[OUT:.+]] = alloca [2 x i8] + // CHECK: %[[IS_NONE:.+]] = icmp eq i16 %x, 0 // CHECK: %[[OPT_DISCR:.+]] = select i1 %[[IS_NONE]], i64 0, i64 1 // CHECK: %[[OPT_DISCR_T:.+]] = trunc nuw i64 %[[OPT_DISCR]] to i1 // CHECK: br i1 %[[OPT_DISCR_T]], label %[[BB_SOME:.+]], label %[[BB_NONE:.+]] + + // CHECK: [[BB_SOME]]: + // CHECK: store i16 987, ptr %[[OUT]] + + // CHECK: [[BB_NONE]]: + // CHECK: store i16 123, ptr %[[OUT]] + + // CHECK: %[[RET:.+]] = load i16, ptr %[[OUT]] + // CHECK: ret i16 %[[RET]] + match x { None => 123, Some(_) => 987, |