Fix optimization pass not converging. (#2725)

* Fix optimization pass not converging.

* Fix.

* Fix tests.

---------

Co-authored-by: Yong He <yhe@nvidia.com>

1 files changed, 16 insertions, 2 deletions

diff --git a/source/slang/slang-ir.cpp b/source/slang/slang-ir.cpp
index 206d73e3f..69870c128 100644
--- a/source/slang/slang-ir.cpp
+++ b/source/slang/slang-ir.cpp
@@ -7093,8 +7093,6 @@ namespace Slang
         case kIROp_Add:
         case kIROp_Sub:
         case kIROp_Mul:
-        //case kIROp_Div:   // TODO: We could split out integer vs. floating-point div/mod and assume the floating-point cases have no side effects
-        //case kIROp_Rem:
         case kIROp_Lsh:
         case kIROp_Rsh:
         case kIROp_Eql:
@@ -7138,6 +7136,22 @@ namespace Slang
         case kIROp_BackwardDifferentiatePropagate:
         case kIROp_DetachDerivative:
             return false;
+
+        case kIROp_Div:
+        case kIROp_IRem:
+            if (isIntegralScalarOrCompositeType(getFullType()))
+            {
+                if (auto intLit = as<IRIntLit>(getOperand(1)))
+                {
+                    if (intLit->getValue() != 0)
+                        return false;
+                }
+                return true;
+            }
+            return false;
+
+        case kIROp_FRem:
+            return false;
         }
         return true;
     }