refactor(tvix/eval): Compile OpAssert using conditional jumps r/5082

In order to behave nicely with tryEval, asserts need to leave the
instruction pointer in a reasonable place even if they fail - whereas
with the previous implementation catching a failed assert would still
end up running the op for the *body* of the assert. With this change, we
compile asserts much more like an `if` expression with conditional jumps
rather than having an OpAssert op.

Change-Id: I1b266c3be90185c84000da6b1995ac3e6fd5471b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6925
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI

1 files changed, 2 insertions, 4 deletions

diff --git a/tvix/eval/src/vm.rs b/tvix/eval/src/vm.rs
index b89b61f7626a..01299ccc17da 100644
--- a/tvix/eval/src/vm.rs
+++ b/tvix/eval/src/vm.rs
@@ -561,10 +561,8 @@ impl<'o> VM<'o> {
                     }
                 }
 
-                OpCode::OpAssert => {
-                    if !fallible!(self, self.pop().as_bool()) {
-                        return Err(self.error(ErrorKind::AssertionFailed));
-                    }
+                OpCode::OpAssertFail => {
+                    return Err(self.error(ErrorKind::AssertionFailed));
                 }
 
                 OpCode::OpCall => {