Arithmetic simplifications and more IR clean up logic. (#2632)

1 files changed, 5 insertions, 2 deletions

diff --git a/source/slang/slang-ir-dce.cpp b/source/slang/slang-ir-dce.cpp
index 33e5b3cb4..337caa246 100644
--- a/source/slang/slang-ir-dce.cpp
+++ b/source/slang/slang-ir-dce.cpp
@@ -3,6 +3,7 @@
 
 #include "slang-ir.h"
 #include "slang-ir-insts.h"
+#include "slang-ir-util.h"
 
 namespace Slang
 {
@@ -16,6 +17,7 @@ struct DeadCodeEliminationContext
     // `eliminateDeadCode` function.
     //
     IRModule*                       module;
+
     IRDeadCodeEliminationOptions    options;
 
     // If we removed an inst, there may be still "weak references" to the inst.
@@ -129,6 +131,9 @@ struct DeadCodeEliminationContext
             auto inst = workList.getLast();
             workList.removeLast();
 
+            if (!isChildInstOf(inst, root))
+                continue;
+
             // At this point we know that `inst` is live,
             // and we want to start considering which other
             // instructions must be live because of that
@@ -426,7 +431,6 @@ bool eliminateDeadCode(
     DeadCodeEliminationContext context;
     context.module = module;
     context.options = options;
-
     return context.processModule();
 }
 
@@ -437,7 +441,6 @@ bool eliminateDeadCode(
     DeadCodeEliminationContext context;
     context.module = root->getModule();
     context.options = options;
-
     return context.processInst(root);
 }