Merge pull request #412 from InnovativeInventor/ssa-ssu-bug-fix

Disable incorrect SSU enforcement in Brili reference interpreter

Author: sampsyo

brili.ts

@@ -749,7 +749,6 @@ function evalInstr(instr: bril.Instruction, state: State): Action {
         throw error(`get without corresponding set for ${instr.dest}`);
       } else {
         state.env.set(instr.dest, val);
-        state.ssaEnv.delete(instr.dest); // Consume the shadow value (enforce SSU).
       }
 
       return NEXT;

test/interp-error/ssa-error/double-phi.bril

@@ -0,0 +1,16 @@
+@main() {
+  one: int = const 1;
+  set shadow one;
+  main.cond: bool = const true;
+  set cond main.cond;
+.test:
+  cond: bool = get;
+  shadow: int = get;
+  br cond .false .end;
+.false:
+  false.cond: bool = const false;
+  set cond false.cond;
+  jmp .test;
+.end:
+  print shadow;
+}

test/interp/core/ssu-regression.bril

@@ -0,0 +1 @@
+1