Added a new differential type system and various improvements (#2343)

* Merge slang-ir-diff-jvp.cpp

* Added support and tests for other float vector types

* Added swizzle test and code to handle it (tests failing currently)

* Fixed one test, the other is still pending

* Fixed instruction cloning logic to avoid modifying original function

* Fixed an issue with custom 'pow_jvp' and added support for vector contructor

* Minor update to comments

* Fixed support for division

* Fixed an issue with uninitialized diagnostic sink

* Moved derivative processing to after mandatory inlining.

Skip instructions that don't have side-effects and aren't used by anything.

* WIP: Handling unconditional control flow and multi-block functions

* Support for unconditional multi-block functions

* Added a dead code elimination step to the derivative pass

* Changed name of 'hasNoSideEffects()'

* Refactored variable names

* Added initial IR defs for new type system

* Added necessary logic for semantic checking

* Overhauled type system to use builtin pair types and conform to the IDifferentiable interface

* Automatically replace IRDifferentiablePairType to a custom IRStructType

* Added generics handling by expanding the conformance context functionality and allowing for type parameters

* Minor fix: early return in processPairTypes()

* Minor fixes to differentiable resolution on generic types

* Added new instructions for differential pairs. Basic tests work now.

Looking into generic types.

* Adjusted most tests to the new type system. OutType and InOutType are still not properly working.

* Updated __jvp to produce both primal and differential output

* Moved autodiff related declarations to diff.meta.slang

* Refactored variable names

* Added initial IR defs for new type system

* Added necessary logic for semantic checking

* Overhauled type system to use builtin pair types and conform to the IDifferentiable interface

* Automatically replace IRDifferentiablePairType to a custom IRStructType

* Added generics handling by expanding the conformance context functionality and allowing for type parameters

* Minor fix: early return in processPairTypes()

* Minor fixes to differentiable resolution on generic types

* Added new instructions for differential pairs. Basic tests work now.

Looking into generic types.

* Adjusted most tests to the new type system. OutType and InOutType are still not properly working.

* Updated __jvp to produce both primal and differential output

* Moved autodiff related declarations to diff.meta.slang

* Removed external changes

* Cleanup the transcription logic: each case returns a pair of insts for the primal and differential computation.

1 files changed, 20 insertions, 0 deletions

diff --git a/source/slang/slang-ir.cpp b/source/slang/slang-ir.cpp
index 86586c2e8..c66f0d555 100644
--- a/source/slang/slang-ir.cpp
+++ b/source/slang/slang-ir.cpp
@@ -2741,6 +2741,17 @@ namespace Slang
             operands);
     }
 
+    IRDifferentialPairType* IRBuilder::getDifferentialPairType(
+        IRType* valueType,
+        IRWitnessTable* witnessTable)
+    {
+        IRInst* operands[] = { valueType, witnessTable };
+        return (IRDifferentialPairType*)getType(
+            kIROp_DifferentialPairType,
+            sizeof(operands) / sizeof(operands[0]),
+            operands);
+    }
+
     IRFuncType* IRBuilder::getFuncType(
         UInt            paramCount,
         IRType* const*  paramTypes,
@@ -3043,6 +3054,15 @@ namespace Slang
         return inst;
     }
 
+    IRInst* IRBuilder::emitMakeDifferentialPair(IRType* type, IRInst* primal, IRInst* differential)
+    {
+        IRInst* args[] = {primal, differential};
+        auto inst = createInstWithTrailingArgs<IRMakeDifferentialPair>(
+            this, kIROp_MakeDifferentialPair, type, 2, args);
+        addInst(inst);
+        return inst;
+    }
+
     IRInst* IRBuilder::emitSpecializeInst(
         IRType*         type,
         IRInst*         genericVal,