Report AD checkpoint contexts (#5058)

* Transferring source locations when creating phi instructions

* Tracking for simple variables

* Deriving source locations for loop counters

* Printing checkpoint structure breakdown

* More readable output format

* Special behavior for loop counters

* Writing report to file

* Add slangc option to enable checkpoint reports

* Display types of checkpointed fields

* Message in case there are no checkpointing contexts

* Catch source locations for function calls

* Source cleanup

* Fix compilation warnings

* Remove stray dump()

* Provide the report through diagnostic notes

* Add missing path for sourceLoc during unzip pass

* Add tests for reporting intermediates

* Include more transfer cases for source locations

* Fix ordering in address elimination

* Fill in more holes with source location transfer

* Remove debugging line

* Reverting changes to diagnostic sink

* Simplify address elimination using source location RAII contexts

* Eliminating manual source loc transfers in forward transcription

* Fix local var adaptation to use RAII location setter

* Simplify primal hoisting logic for source location transfer

* Simplify unzipping with RAII location scopes

* Simplify transpose logic

* Cleaning up for rev.cpp

* Reverting spacing changes

* Fix mistake with source loc RAII instantiation

* Fix formatting issues

1 files changed, 9 insertions, 2 deletions

diff --git a/tests/autodiff/reverse-control-flow-3.slang b/tests/autodiff/reverse-control-flow-3.slang
index 01b533279..b4fa68e3a 100644
--- a/tests/autodiff/reverse-control-flow-3.slang
+++ b/tests/autodiff/reverse-control-flow-3.slang
@@ -1,4 +1,5 @@
 //TEST(compute, vulkan):COMPARE_COMPUTE_EX:-vk -compute -shaderobj -output-using-type
+//TEST:SIMPLE(filecheck=CHK):-target glsl -stage compute -entry computeMain -report-checkpoint-intermediates
 
 //TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=outputBuffer
 
@@ -75,7 +76,8 @@ void d_getParam(uint id, MaterialParam.Differential diff)
     outputBuffer[id] += diff.roughness;
 }
 
-
+//CHK-DAG: note: checkpointing context of 8 bytes associated with function: 'updatePathThroughput'
+//CHK-DAG: note: 8 bytes (PathResult_0) used to checkpoint the following item:
 [BackwardDifferentiable]
 void updatePathThroughput(inout PathResult path, const float weight)
 {
@@ -122,9 +124,13 @@ bool generateScatterRay(const BSDFSample bs, const MaterialParam bsdfParams, ino
     \param[in,out] path The path state.
     \return True if a ray was generated, false otherwise.
 */
+
+//CHK-DAG: note: checkpointing context of 16 bytes associated with function: 'generateScatterRay'
 [BackwardDifferentiable]
 bool generateScatterRay(const BSDFSample bs, const MaterialParam bsdfParams, inout PathState path, inout PathResult pathRes)
 {
+    //CHK-DAG: note: 8 bytes (s_bwd_prop_updatePathThroughput_Intermediates_0) used to checkpoint the following item:
+    //CHK-DAG: note: 8 bytes (PathResult_0) used to checkpoint the following item:
     updatePathThroughput(pathRes, bs.val);
     return true;
 }
@@ -215,5 +221,6 @@ void computeMain(uint3 dispatchThreadID: SV_DispatchThreadID)
         var dpx = diffPair(pathRes, pathResD);
         __bwd_diff(tracePath)(1, dpx); // Expect: 5.0 in outputBuffer[3]
     }
-
 }
+
+//CHK-NOT: note
\ No newline at end of file