From a9470d0522368f67d8aaa551318e3feb2d18e790 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tomasz=20Mi=C4=85sko?= <tomasz.miasko@gmail.com>
Date: Wed, 21 Oct 2020 00:00:00 +0000
Subject: [PATCH] Simplify assert terminator only if condition evaluates to
 expected value

---
 compiler/rustc_mir/src/transform/simplify_branches.rs | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/compiler/rustc_mir/src/transform/simplify_branches.rs b/compiler/rustc_mir/src/transform/simplify_branches.rs
index 5f63c03993d..a9a45e61a38 100644
--- a/compiler/rustc_mir/src/transform/simplify_branches.rs
+++ b/compiler/rustc_mir/src/transform/simplify_branches.rs
@@ -49,9 +49,10 @@ impl<'tcx> MirPass<'tcx> for SimplifyBranches {
                 }
                 TerminatorKind::Assert {
                     target, cond: Operand::Constant(ref c), expected, ..
-                } if (c.literal.try_eval_bool(tcx, param_env) == Some(true)) == expected => {
-                    TerminatorKind::Goto { target }
-                }
+                } => match c.literal.try_eval_bool(tcx, param_env) {
+                    Some(v) if v == expected => TerminatorKind::Goto { target },
+                    _ => continue,
+                },
                 TerminatorKind::FalseEdge { real_target, .. } => {
                     TerminatorKind::Goto { target: real_target }
                 }