From d40c143eb4f19f1dfd0d0dcf9b718be6e495ca27 Mon Sep 17 00:00:00 2001 From: Sai Praveen Bangaru <31557731+saipraveenb25@users.noreply.github.com> Date: Tue, 27 Aug 2024 15:00:43 -0400 Subject: Explicitly detach derivative when forming a non-differentiable struct out of differentiable args (#4901) * Explicitly detach derivative when forming a non-differentiable struct out of differentiable args This fixes an issue where initializer lists get optimized out and lose information about non-differentiability. There are 2 places where this could have been fixed: 1. When coercing initializer-list exprs, we can check for non-differentiable aggregate types and use a detach derivative on all the args. 2. Add an extra case in the peephole optimization step that adds detach-derivative when simplifying a make-struct of a non-differentiable type. Even though solution 2 is more elegant, this PR goes with solution 1 simply to avoid having to use a differentiable-type-conformance-context that is used in the auto-diff IR passes to check for differentiability. * Change test name + add expected vals --- source/slang/slang-lower-to-ir.cpp | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'source/slang/slang-lower-to-ir.cpp') diff --git a/source/slang/slang-lower-to-ir.cpp b/source/slang/slang-lower-to-ir.cpp index 02c4fae68..b9d7a898f 100644 --- a/source/slang/slang-lower-to-ir.cpp +++ b/source/slang/slang-lower-to-ir.cpp @@ -3929,6 +3929,16 @@ struct ExprLoweringVisitorBase : public ExprVisitor baseVal.val)); } + LoweredValInfo visitDetachExpr(DetachExpr* expr) + { + auto baseVal = lowerRValueExpr(context, expr->inner); + + return LoweredValInfo::simple( + getBuilder()->emitDetachDerivative( + lowerType(context, expr->type), + getSimpleVal(context, baseVal))); + } + LoweredValInfo visitPrimalSubstituteExpr(PrimalSubstituteExpr* expr) { auto baseVal = lowerSubExpr(expr->baseFunction); -- cgit v1.2.3