Optimize specialization, and remove unnecessary calls to `simplifyIR`. (#2999)

* Remove unneccessary calls to `simplifyIR`.

* fix.

* Delete obsolete hoistConst pass.

* Fix.

* Small improvements.

* Fix.

* Fix enum lowering.

* fix

* tweaks.

* tweaks.

---------

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

1 files changed, 32 insertions, 4 deletions

diff --git a/source/slang/slang-ir-sccp.cpp b/source/slang/slang-ir-sccp.cpp
index d5e4c6e99..ce635dca8 100644
--- a/source/slang/slang-ir-sccp.cpp
+++ b/source/slang/slang-ir-sccp.cpp
@@ -1248,12 +1248,30 @@ struct SCCPContext
         }
     }
 
-    // Run the constant folding on global scope only.
+    // Run the constant folding on global scope and specialized types only.
     bool applyOnGlobalScope(IRModule* module)
     {
-        builderStorage = IRBuilder(shared->module);
+        bool changed = applyOnScope(module->getModuleInst());
         for (auto child : module->getModuleInst()->getChildren())
         {
+            switch (child->getOp())
+            {
+            case kIROp_StructType:
+            case kIROp_ClassType:
+            case kIROp_InterfaceType:
+            case kIROp_WitnessTable:
+                changed |= applyOnScope(child);
+                break;
+            }
+        }
+        return changed;
+    }
+
+    bool applyOnScope(IRInst* scopeInst)
+    {
+        builderStorage = IRBuilder(scopeInst);
+        for (auto child : scopeInst->getChildren())
+        {
             // Only consider evaluable opcodes.
             if (!isEvaluableOpCode(child->getOp()))
                 continue;
@@ -1265,7 +1283,7 @@ struct SCCPContext
             auto inst = ssaWorkList[0];
             ssaWorkList.fastRemoveAt(0);
             // Only consider evaluable opcodes and insts at global scope.
-            if (!isEvaluableOpCode(inst->getOp()) || inst->getParent() != module->getModuleInst())
+            if (!isEvaluableOpCode(inst->getOp()) || inst->getParent() != scopeInst)
                 continue;
             updateValueForInst(inst);
         }
@@ -1273,7 +1291,7 @@ struct SCCPContext
         bool changed = false;
         // Replace the insts with their values.
         List<IRInst*> instsToRemove;
-        for (auto child : module->getModuleInst()->getChildren())
+        for (auto child : scopeInst->getChildren())
         {
             if (!isEvaluableOpCode(child->getOp()))
                 continue;
@@ -1670,6 +1688,16 @@ static bool applySparseConditionalConstantPropagationRec(
 
     for( auto childInst : inst->getDecorationsAndChildren() )
     {
+        switch (childInst->getOp())
+        {
+        case kIROp_Func:
+        case kIROp_Block:
+        case kIROp_Generic:
+            break;
+        default:
+            // Skip other op codes.
+            continue;
+        }
         changed |= applySparseConditionalConstantPropagationRec(globalContext, childInst);
     }
     return changed;