diff options
| author | Eduard-Mihai Burtescu <edy.burt@gmail.com> | 2018-06-16 14:19:05 +0300 |
|---|---|---|
| committer | Eduard-Mihai Burtescu <edy.burt@gmail.com> | 2018-06-16 16:00:53 +0300 |
| commit | 25c47a48858122b3b20a4a5f08ecbf13eb15e19d (patch) | |
| tree | ce4b3afab421717f93725596d162604df7f91e75 /src/librustc_codegen_llvm | |
| parent | 68cee8bb36d8cf0c5fe1e9b7ffa0bf096ac5bd68 (diff) | |
| download | rust-25c47a48858122b3b20a4a5f08ecbf13eb15e19d.tar.gz rust-25c47a48858122b3b20a4a5f08ecbf13eb15e19d.zip | |
rustc_codegen_llvm: don't treat i1 as signed, even for #[repr(i8)] enums.
Diffstat (limited to 'src/librustc_codegen_llvm')
| -rw-r--r-- | src/librustc_codegen_llvm/mir/place.rs | 6 | ||||
| -rw-r--r-- | src/librustc_codegen_llvm/mir/rvalue.rs | 6 |
2 files changed, 10 insertions, 2 deletions
diff --git a/src/librustc_codegen_llvm/mir/place.rs b/src/librustc_codegen_llvm/mir/place.rs index bda8c758750..2a1e3980adb 100644 --- a/src/librustc_codegen_llvm/mir/place.rs +++ b/src/librustc_codegen_llvm/mir/place.rs @@ -275,7 +275,11 @@ impl<'a, 'tcx> PlaceRef<'tcx> { layout::Variants::Single { .. } => bug!(), layout::Variants::Tagged { ref tag, .. } => { let signed = match tag.value { - layout::Int(_, signed) => signed, + // We use `i1` for bytes that are always `0` or `1`, + // e.g. `#[repr(i8)] enum E { A, B }`, but we can't + // let LLVM interpret the `i1` as signed, because + // then `i1 1` (i.e. E::B) is effectively `i8 -1`. + layout::Int(_, signed) => !tag.is_bool() && signed, _ => false }; bx.intcast(lldiscr, cast_to, signed) diff --git a/src/librustc_codegen_llvm/mir/rvalue.rs b/src/librustc_codegen_llvm/mir/rvalue.rs index d1b949d4f73..0fd81c6074e 100644 --- a/src/librustc_codegen_llvm/mir/rvalue.rs +++ b/src/librustc_codegen_llvm/mir/rvalue.rs @@ -298,7 +298,11 @@ impl<'a, 'tcx> FunctionCx<'a, 'tcx> { let mut signed = false; if let layout::Abi::Scalar(ref scalar) = operand.layout.abi { if let layout::Int(_, s) = scalar.value { - signed = s; + // We use `i1` for bytes that are always `0` or `1`, + // e.g. `#[repr(i8)] enum E { A, B }`, but we can't + // let LLVM interpret the `i1` as signed, because + // then `i1 1` (i.e. E::B) is effectively `i8 -1`. + signed = !scalar.is_bool() && s; if scalar.valid_range.end() > scalar.valid_range.start() { // We want `table[e as usize]` to not |