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| author | bors <bors@rust-lang.org> | 2017-12-27 10:19:43 +0000 |
|---|---|---|
| committer | bors <bors@rust-lang.org> | 2017-12-27 10:19:43 +0000 |
| commit | 71ed31f24054863b807f68f244c6828ce6d2e516 (patch) | |
| tree | 398510c60a4095ce0f185401880fa51e9ae173f9 /src | |
| parent | 3fd27b2718438ceec6243869cde3edde7e5a904e (diff) | |
| parent | 97228f5e7b0d6a0dc5c97fa73fa7ab096e4eb58d (diff) | |
| download | rust-71ed31f24054863b807f68f244c6828ce6d2e516.tar.gz rust-71ed31f24054863b807f68f244c6828ce6d2e516.zip | |
Auto merge of #47007 - eddyb:issue-46897, r=arielb1
rustc: don't use union layouts for tagged union enums. Fixes #46897, fixes #43517 (AFAICT from the testcases). This PR doesn't add any testcases, we should try to at least get perf ones (cc @Mark-Simulacrum). I couldn't find an example in those issues where the choice of LLVM array vs struct (with N identical fields) for padding filler types is still needed, *on top of* this change, to prevent excessive LLVM sinking. r? @arielb1
Diffstat (limited to 'src')
| -rw-r--r-- | src/librustc/ty/layout.rs | 8 | ||||
| -rw-r--r-- | src/test/codegen/align-struct.rs | 5 |
2 files changed, 7 insertions, 6 deletions
diff --git a/src/librustc/ty/layout.rs b/src/librustc/ty/layout.rs index bf76f6e7d1d..017b16e4126 100644 --- a/src/librustc/ty/layout.rs +++ b/src/librustc/ty/layout.rs @@ -1655,10 +1655,10 @@ impl<'a, 'tcx> LayoutDetails { discr, variants }, - // FIXME(eddyb): using `FieldPlacement::Arbitrary` here results - // in lost optimizations, specifically around allocations, see - // `test/codegen/{alloc-optimisation,vec-optimizes-away}.rs`. - fields: FieldPlacement::Union(1), + fields: FieldPlacement::Arbitrary { + offsets: vec![Size::from_bytes(0)], + memory_index: vec![0] + }, abi, align, size diff --git a/src/test/codegen/align-struct.rs b/src/test/codegen/align-struct.rs index 3b720dc30d3..ab9f5dda3a1 100644 --- a/src/test/codegen/align-struct.rs +++ b/src/test/codegen/align-struct.rs @@ -32,13 +32,14 @@ pub enum Enum4 { A(i32), B(i32), } -// CHECK: %Enum4 = type { [2 x i32] } +// CHECK: %Enum4 = type { [0 x i32], i32, [1 x i32] } +// CHECK: %"Enum4::A" = type { [1 x i32], i32, [0 x i32] } pub enum Enum64 { A(Align64), B(i32), } -// CHECK: %Enum64 = type { [16 x i64] } +// CHECK: %Enum64 = type { [0 x i32], i32, [31 x i32] } // CHECK: %"Enum64::A" = type { [8 x i64], %Align64, [0 x i64] } // CHECK-LABEL: @align64 |