SSA Register Allocation improvements. (#2857)

* SSA Register Allocation improvements.

* Fix.

* Rename `Use`->`UseOrPseudoUse`.

---------

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

1 files changed, 15 insertions, 0 deletions

diff --git a/source/slang/slang-ir-util.cpp b/source/slang/slang-ir-util.cpp
index a69e13562..95240a26c 100644
--- a/source/slang/slang-ir-util.cpp
+++ b/source/slang/slang-ir-util.cpp
@@ -759,6 +759,21 @@ void removePhiArgs(IRInst* phiParam)
     }
 }
 
+int getParamIndexInBlock(IRParam* paramInst)
+{
+    auto block = as<IRBlock>(paramInst->getParent());
+    if (!block)
+        return -1;
+    int paramIndex = 0;
+    for (auto param : block->getParams())
+    {
+        if (param == paramInst)
+            return paramIndex;
+        paramIndex++;
+    }
+    return -1;
+}
+
 struct GenericChildrenMigrationContextImpl
 {
     IRCloneEnv cloneEnv;