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, 33 insertions, 2 deletions

diff --git a/source/slang/slang-options.cpp b/source/slang/slang-options.cpp
index c3a0eeddc..33103442d 100644
--- a/source/slang/slang-options.cpp
+++ b/source/slang/slang-options.cpp
@@ -353,7 +353,9 @@ void initCommandOptions(CommandOptions& options)
         "The language to be used for source embedding. Defaults to C/C++. Currently only C/C++ are supported"},
         { OptionKind::DisableShortCircuit, "-disable-short-circuit", nullptr, "Disable short-circuiting for \"&&\" and \"||\" operations" },
         { OptionKind::UnscopedEnum, "-unscoped-enum", nullptr, "Treat enums types as unscoped by default."},
-        { OptionKind::PreserveParameters, "-preserve-params", nullptr, "Preserve all resource parameters in the output code, even if they are not used by the shader."}
+        { OptionKind::PreserveParameters, "-preserve-params", nullptr, "Preserve all resource parameters in the output code, even if they are not used by the shader."},
+        { OptionKind::EmbedDXIL, "-embed-dxil", nullptr,
+        "Embed DXIL into emitted slang-modules for faster linking" },
     };
 
     _addOptions(makeConstArrayView(generalOpts), options);
@@ -426,7 +428,6 @@ void initCommandOptions(CommandOptions& options)
         "A path to a specific spirv.core.grammar.json to use when generating SPIR-V output" },
         { OptionKind::IncompleteLibrary, "-incomplete-library", nullptr,
         "Allow generating code from incomplete libraries with unresolved external functions" },
-
     };
 
     _addOptions(makeConstArrayView(targetOpts), options);
@@ -699,6 +700,8 @@ struct OptionsParser
     void setProfileVersion(RawTarget* rawTarget, ProfileVersion profileVersion);
     void setProfile(RawTarget* rawTarget, Profile profile);
     void addCapabilityAtom(RawTarget* rawTarget, CapabilityName atom);
+
+    SlangResult addEmbeddedLibrary(const CodeGenTarget format, CompilerOptionName option);
     
     void setFloatingPointMode(RawTarget* rawTarget, FloatingPointMode mode);
     
@@ -1636,6 +1639,23 @@ SlangResult OptionsParser::_parseProfile(const CommandLineArg& arg)
     return SLANG_OK;
 }
 
+// Creates a target of the specified type whose output will be embedded as IR metadata
+SlangResult OptionsParser::addEmbeddedLibrary(const CodeGenTarget format, CompilerOptionName option)
+{
+    RawTarget rawTarget;
+    rawTarget.format = format;
+    // Silently allow redundant targets if it is the same as the last specified target.
+    if (m_rawTargets.getCount() == 0 || m_rawTargets.getLast().format != rawTarget.format)
+    {
+        m_rawTargets.add(rawTarget);
+    }
+
+    getCurrentTarget()->optionSet.add(option, true);
+    getCurrentTarget()->optionSet.add(CompilerOptionName::GenerateWholeProgram, true);
+
+    return SLANG_OK;
+}
+
 SlangResult OptionsParser::_parse(
     int             argc,
     char const* const* argv)
@@ -1927,6 +1947,7 @@ SlangResult OptionsParser::_parse(
                 linkage->m_optionSet.set(optionKind, compressionType);
                 break;
             }
+            case OptionKind::EmbedDXIL: SLANG_RETURN_ON_FAIL(addEmbeddedLibrary(CodeGenTarget::DXIL, CompilerOptionName::EmbedDXIL)); break;
             case OptionKind::Target:
             {
                 CommandLineArg name;
@@ -2758,6 +2779,16 @@ SlangResult OptionsParser::_parse(
             {
                 m_compileRequest->setTargetForceGLSLScalarBufferLayout(targetID, true);
             }
+
+            if (rawTarget.optionSet.getBoolOption(CompilerOptionName::GenerateWholeProgram))
+            {
+                m_compileRequest->setTargetGenerateWholeProgram(targetID, true);
+            }
+
+            if (rawTarget.optionSet.getBoolOption(CompilerOptionName::EmbedDXIL))
+            {
+                m_compileRequest->setTargetEmbedDXIL(targetID, true);
+            }
         }
 
         // Next we need to sort out the output files specified with `-o`, and