Fix for missing signedness cast in SwizzleIR (#7448)

* Cast if there is a signedness mismatch on the swizzle

* Move isSignedType to slang-util and add test

---------

Co-authored-by: Yong He <yonghe@outlook.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/source/slang/slang-ir-util.cpp b/source/slang/slang-ir-util.cpp
index 13742711c..a2ec15661 100644
--- a/source/slang/slang-ir-util.cpp
+++ b/source/slang/slang-ir-util.cpp
@@ -2348,4 +2348,25 @@ bool isInstHoistable(IROp op, IRType* type, IRInst* const* fixedArgs)
            isSpecConstOpHoistable(op, type, fixedArgs);
 }
 
+bool isSignedType(IRType* type)
+{
+    switch (type->getOp())
+    {
+    case kIROp_FloatType:
+    case kIROp_DoubleType:
+        return true;
+    case kIROp_IntType:
+    case kIROp_Int16Type:
+    case kIROp_Int64Type:
+    case kIROp_Int8Type:
+        return true;
+    case kIROp_VectorType:
+        return isSignedType(as<IRVectorType>(type)->getElementType());
+    case kIROp_MatrixType:
+        return isSignedType(as<IRMatrixType>(type)->getElementType());
+    default:
+        return false;
+    }
+}
+
 } // namespace Slang