diff options
| -rw-r--r-- | src/librustc_mir/transform/simplify_branches.rs | 32 |
1 files changed, 18 insertions, 14 deletions
diff --git a/src/librustc_mir/transform/simplify_branches.rs b/src/librustc_mir/transform/simplify_branches.rs index 424250586b1..3d5106c4b06 100644 --- a/src/librustc_mir/transform/simplify_branches.rs +++ b/src/librustc_mir/transform/simplify_branches.rs @@ -30,26 +30,30 @@ impl<'l, 'tcx> MirPass<'tcx> for SimplifyBranches<'l> { for block in mir.basic_blocks_mut() { let terminator = block.terminator_mut(); terminator.kind = match terminator.kind { - // TerminatorKind::If { ref targets, cond: Operand::Constant(Constant { - // literal: Literal::Value { - // value: ConstVal::Bool(cond) - // }, .. - // }) } => { - // if cond { - // TerminatorKind::Goto { target: targets.0 } - // } else { - // TerminatorKind::Goto { target: targets.1 } - // } - // } - + TerminatorKind::SwitchInt { discr: Operand::Constant(Constant { + literal: Literal::Value { ref value }, .. + }), ref values, ref targets, .. } => { + if let Some(ref constint) = value.to_const_int() { + let (otherwise, targets) = targets.split_last().unwrap(); + let mut ret = TerminatorKind::Goto { target: *otherwise }; + for (v, t) in values.iter().zip(targets.iter()) { + if v == constint { + ret = TerminatorKind::Goto { target: *t }; + break; + } + } + ret + } else { + continue + } + }, TerminatorKind::Assert { target, cond: Operand::Constant(Constant { literal: Literal::Value { value: ConstVal::Bool(cond) }, .. }), expected, .. } if cond == expected => { TerminatorKind::Goto { target: target } - } - + }, _ => continue }; } |