Initial support for precompiled DXIL in slang-modules (#4755)

* Add embedded precompiled binary IR ops

Add IR operations to embed precompiled DXIL or SPIR-V blobs
into IR. Adds a BlobLit literal that is mostly identical to
StringLit except for its inability to be displayed, e.g.
in dumped IR. In the future, the blob might be dumped as
hexadecimal, but for now it is summarized as "<binary blob>".

* EmbeddedDXIL and SPIR-V options

The options, '-embed-dxil' and '-embed-spirv' in slangc, will
cause a target dxil or spirv to be compiled and stored in the
translation unit IR when written to a slang-module. Subsequent
changes actually implement the options.

* Per-translation unit DXIL precompilation

When -embed-dxil is specified, perform a precompilation to DXIL of
each TU, linked only with stdlib. Embed the resulting DXIL for
the TU in a IR op. Being part of IR, the precompiled DXIL can be
serialized to disk in a slang-module.

Upon loading slang-modules, the new IR op will be searched for and
the precompiled DXIL blob is saved with the loaded Module. During
linking, if all the Modules have precompiled blobs they will be
sent to the downstream compile commands as libraries instead of
source, skipping the downstream compilation, using DXC only for
linking.

Fixes Issue #4580

* Remove placeholder embedded SPIRV support

Code was added only to sketch out how other precompiled bins
will be supported.

* Remove the rest of the SPIRV placeholder support

* Fix warnings, test error on non-windows

* Remove lib_6_6 hack, add dxil_lib capability

* Allocate blob value from irmodule memarena

* Add null check after memarena allocation

* Restore the request->e2erequest code path for generatewholeprogram

* Update capability handling, move EmbedDXIL enum to end to preserve abi

* Remove lib_6_6 hack

* Move ICompileRequest functions to end

1 files changed, 24 insertions, 0 deletions

diff --git a/tests/library/precompiled-dxil.slang b/tests/library/precompiled-dxil.slang
new file mode 100644
index 000000000..19f67b075
--- /dev/null
+++ b/tests/library/precompiled-dxil.slang
@@ -0,0 +1,24 @@
+// precompiled-dxil.slang
+
+// A test that uses slang-modules with embedded precompiled DXIL.
+// The test compiles both library slang (export-library.slang) and entrypoint slang (this file) to two slang-modules, each with -embed-dxil options.
+// The result is two slang-modules that are then linked together in a third slangc invocation.
+// Internally, slang does not use the IR in the modules to link, but rather their embedded DXIL.
+// The test passes if there is no errror thrown.
+// TODO: Check if final linkage used only the precompiled dxil.
+
+//TEST(windows):COMPILE: tests/library/export-library.slang -o tests/library/export-library.slang-module -embed-dxil -profile lib_6_6 -incomplete-library
+//TEST(windows):COMPILE: tests/library/precompiled-dxil.slang -o tests/library/precompiled-dxil.slang-module -embed-dxil -profile lib_6_6 -incomplete-library
+//TEST(windows):COMPILE: tests/library/export-library.slang-module tests/library/precompiled-dxil.slang-module -target dxil -entry computeMain -profile cs_6_6 -o tests/library/linked.dxil
+
+extern int foo(int a);
+
+RWStructuredBuffer<int> outputBuffer;
+
+[shader("compute")]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    int index = (int)dispatchThreadID.x;
+
+    outputBuffer[index] = foo(index);
+}