Making it easier to work with shaders https://git.yummers.dev/slang.git/atom?h=master 2018-04-23T17:37:56+00:00 2018-04-23T17:37:56+00:00 Tim Foley tfoleyNV@users.noreply.github.com 2018-04-23T17:37:56+00:00 urn:sha1:9a7849d893ebb755a607befff6b3429830421112 * Improve SSA promotion for arrays and structs Fixes #518 The existing SSA pass would only handle `load(v)` and `store(v,...)` where `v` is the variable instruction, and would bail out if `v` was used as an operand in any other fashion. The new pass adds support for `load(ac)` where `ac` is an "access chain" with a gramar like: ac :: v | getElementPtr(ac, ...) | getFieldAddress(ac, ...) What this means in practical terms is that we can promote a local variable of array or structure type to an SSA temporary even if there are loads of individual elements/fields, as along as any *assignment* to the variable assigns the whole thing. I've added a test case to confirm that this change fixes passing of arrays as function parameters for Vulkan. * Fixup: disable test on Vulkan because render-test isn't ready This is a fix for Vulkan, but I don't think our testing setup is ready for it. * Fixup: error in unreachable return case, caught by clang * Fixups based on testing These are fixes found when testing the original changes against the user code that originated the bug report. * `emit.cpp`: Make sure to handle array-of-texture types when deciding whether to declare a temporary as a local variable in GLSL output * `ir-legalize-types.cpp`: Make a not of a source of validation failures that we need to clean up sooner or later (just not in scope for this bug fix change). * `ir-ssa.cpp`: * When checking if something is an access chain with a promotable var at the end, make sure the recursive case recurses into the "access chain" logic instead of the leaf case * Add some assertions to guard the assumption that any access chain we apply has been scheduled for removal * Correctly emit an element *extract* instead of getting an element *address* when promoting an element access into an array being promoted * Eliminate a wrapper routine that was setting up an `IRBuilder` and use the one from the block being processed in the SSA pass (since it was set up for stuff just like this) * `ir-validate.cpp` * Add a hack to avoid validation failures when running IR validation on the stdlib code. This case triggers for an initializer (`__init`) declaration inside an interface, since the logical "return type" is the interface type itself, which has no representation at the IR level and thus yields a null result type in a `FuncType` instruction.