1 files changed, 96 insertions, 0 deletions
diff --git a/source/slang/slang-ir-hoist-constants.cpp b/source/slang/slang-ir-hoist-constants.cpp
new file mode 100644
index 000000000..87d3487a3
--- /dev/null
+++ b/source/slang/slang-ir-hoist-constants.cpp
@@ -0,0 +1,96 @@
+// slang-ir-hoist-constants.cpp
+#include "slang-ir-hoist-constants.h"
+#include "slang-ir-inst-pass-base.h"
+
+namespace Slang
+{
+
+struct HoistConstantPass : InstPassBase
+{
+    HoistConstantPass(IRModule* module) : InstPassBase(module)
+    {}
+
+    bool changed = false;
+
+    void processModule()
+    {
+        sharedBuilderStorage.init(module);
+
+        processAllInsts([this](IRInst* inst)
+            {
+                
+                if (inst->getParent() == module->getModuleInst() || !inst->getParent())
+                    return;
+                auto parent = inst->getParent();
+                auto p = parent;
+                while (p)
+                {
+                    if (as<IRGlobalValueWithCode>(p))
+                        return;
+                    p = p->parent;
+                }
+                while (parent && parent->parent != module->getModuleInst())
+                    parent = parent->parent;
+                if (!parent)
+                    return;
+                switch (inst->getOp())
+                {
+                default:
+                    return;
+                case kIROp_Add:
+                case kIROp_Sub:
+                case kIROp_Mul:
+                case kIROp_Div:
+                case kIROp_Module:
+                case kIROp_Neg:
+                case kIROp_And:
+                case kIROp_Or:
+                case kIROp_Not:
+                case kIROp_BitAnd:
+                case kIROp_BitNot:
+                case kIROp_BitOr:
+                case kIROp_BitXor:
+                case kIROp_Select:
+                case kIROp_Greater:
+                case kIROp_Less:
+                case kIROp_Leq:
+                case kIROp_Geq:
+                case kIROp_Eql:
+                case kIROp_Neq:
+                case kIROp_BitCast:
+                case kIROp_Lsh:
+                case kIROp_Rsh:
+                case kIROp_Construct:
+                case kIROp_makeVector:
+                case kIROp_MakeMatrix:
+                case kIROp_swizzle:
+                case kIROp_IntLit:
+                case kIROp_BoolLit:
+                case kIROp_ArrayType:
+                case kIROp_Specialize:
+                case kIROp_VectorType:
+                    break;
+                }
+                if (inst->typeUse.get() && inst->typeUse.get()->parent != module->getModuleInst())
+                    return;
+                for (UInt i = 0; i < inst->getOperandCount(); i++)
+                {
+                    if (inst->getOperand(i)->parent != module->getModuleInst())
+                        return;
+                }
+                // all operands are in global scope, we can move this inst to global scope as well.
+                inst->insertBefore(parent);
+                changed = true;
+            });
+    }
+};
+
+bool hoistConstants(
+    IRModule* module)
+{
+    HoistConstantPass context(module);
+    context.processModule();
+    return context.changed;
+}
+
+}