Overhauled reverse-mode control flow handling (#2608)

* Added switch-case support; fixed non-diff parameter transposition

* Made region propagation much more robust. Partial loop unzip implementation

* WIP: Added most loop handling code, and a test. Still untested

* Added CFG Normalization pass + CFG Reversal Pass + Loop Unzipping + most loop transcription

* Add single-iter-loop test.

* proj files

* removed comments

* Update reverse-loop.slang

* Removed out-of-date code

* Disabled IR validation during constructSSA phase of normalizeCFG. constructSSA now reuses sharedBuilder

* Moved normalizeCFG() call to prepareFuncForBackwardDiff()

1 files changed, 26 insertions, 0 deletions

diff --git a/source/slang/slang-ir.cpp b/source/slang/slang-ir.cpp
index 845232ae6..e72ba8c9f 100644
--- a/source/slang/slang-ir.cpp
+++ b/source/slang/slang-ir.cpp
@@ -4764,6 +4764,32 @@ namespace Slang
         return inst;
     }
 
+    IRInst* IRBuilder::emitLoop(
+        IRBlock*      target,
+        IRBlock*      breakBlock,
+        IRBlock*      continueBlock,
+        Int           argCount,
+        IRInst*const* args)
+    {
+        List<IRInst*> argList;
+        
+        argList.add(target);
+        argList.add(breakBlock);
+        argList.add(continueBlock);
+
+        for (Count ii = 0; ii < argCount; ii++)
+            argList.add(args[ii]);
+        
+        auto inst = createInst<IRLoop>(
+            this,
+            kIROp_loop,
+            nullptr,
+            argList.getCount(),
+            argList.getBuffer());
+        addInst(inst);
+        return inst;
+    }
+
     IRInst* IRBuilder::emitBranch(
         IRInst*     val,
         IRBlock*    trueBlock,