Add support for [noinline] attribute (#1650)

This adds the `[noinline]` attribute to the front-end, and passes it through when generating HLSL output.

Notes:

* This change doesn't include a test since the dxc version I have locally parses `[noinline]` but then generates DXIL that fails validation.

* This change doesn't include logic to handle `[noinline]` for other targets. Notably, SPIR-V has decorations that convey the same intention, but we don't yet take advantage of the GLSL extension(s) that would let us generate those decorations.

* By necesstiy, `[noinline]` is only a "strong suggestion" and not actually something the compiler can ever guarantee/enforce.

1 files changed, 14 insertions, 0 deletions

diff --git a/source/slang/slang-emit-hlsl.cpp b/source/slang/slang-emit-hlsl.cpp
index 57d603940..a1da1bbdf 100644
--- a/source/slang/slang-emit-hlsl.cpp
+++ b/source/slang/slang-emit-hlsl.cpp
@@ -693,6 +693,20 @@ void HLSLSourceEmitter::emitLoopControlDecorationImpl(IRLoopControlDecoration* d
     }
 }
 
+void HLSLSourceEmitter::emitFuncDecorationImpl(IRDecoration* decoration)
+{
+    switch( decoration->op )
+    {
+    case kIROp_NoInlineDecoration:
+        m_writer->emit("[noinline]\n");
+        break;
+
+    default:
+        break;
+    }
+}
+
+
 void HLSLSourceEmitter::emitSimpleValueImpl(IRInst* inst)
 {
     switch (inst->op)