Fix metal segfault by check vectorValue before accessing (#7688)

* Check vectorValue before accessing

* Fix metal segfault by using IRElementExtract for general vector handling

Address review comments by replacing IRMakeVector-specific code with
IRElementExtract to handle any vector instruction type (IRIntCast, etc).
This makes the code more robust and fixes cases where float2(1,2)
creates IRIntCast instead of IRMakeVector.

Co-authored-by: Yong He <csyonghe@users.noreply.github.com>

* Fix sign comparison warning in metal legalize

Cast originalElementCount->getValue() to UInt to avoid comparison between signed and unsigned integers.

Co-authored-by: Yong He <csyonghe@users.noreply.github.com>

---------

Co-authored-by: Yong He <yonghe@outlook.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: Yong He <csyonghe@users.noreply.github.com>

1 files changed, 11 insertions, 3 deletions

diff --git a/source/slang/slang-ir-metal-legalize.cpp b/source/slang/slang-ir-metal-legalize.cpp
index 589413cbf..116feeab4 100644
--- a/source/slang/slang-ir-metal-legalize.cpp
+++ b/source/slang/slang-ir-metal-legalize.cpp
@@ -32,10 +32,18 @@ void legalizeImageStoreValue(IRBuilder& builder, IRImageStore* imageStore)
             }
         }
         elementType = valueVectorType->getElementType();
-        auto vectorValue = as<IRMakeVector>(originalValue);
-        for (UInt i = 0; i < vectorValue->getOperandCount(); i++)
+
+        // Extract components using IRElementExtract to handle any vector instruction type
+        if (auto originalElementCount = as<IRIntLit>(valueVectorType->getElementCount()))
         {
-            components.add(vectorValue->getOperand(i));
+            for (UInt i = 0; i < (UInt)originalElementCount->getValue(); i++)
+            {
+                auto elementExtract = builder.emitElementExtract(
+                    elementType,
+                    originalValue,
+                    builder.getIntValue(builder.getIntType(), i));
+                components.add(elementExtract);
+            }
         }
     }
     else