swift

a5e83817 - Reapply "Implement several peephole optimizations to unblock further optimizations of autodiff code" with correctness fix (#62012)

Reapply "Implement several peephole optimizations to unblock further optimizations of autodiff code" with correctness fix (#62012) * Implement several peephole optimizations to unblock further optimizations of autodiff code 1. Simplify differentiable_function_extract of differentiable_function. Before: %x = differentiable_function(%orig, %jvp, %vjp) %y = differentiable_function_extract [original] %x After: %y = %orig 2. Push conversion instructions inside of differentiable_function. This unblocks inlining and specialization. Before: %x = differentiable_function(%orig, %jvp, %vjp) %y = convert_escape_to_noescape %x After: %orig' = convert_escape_to_noescape %orig %jvp' = convert_escape_to_noescape %jvp %vjp' = convert_escape_to_noescape %vjp %y = differentiable_function(%orig', %jvp', %vjp') 3. Another peephole is needed for reordering function conversion instructions to enable full inlining: (convert_escape_to_noescape (convert_function (thin_to_thick_function x))) => (convert_escape_to_noescape (thin_to_thick_function (convert_function x))) Co-authored-by: Dan Zheng <danielzheng@google.com>