Continue work on IR-based codegen

This gets us far enough that we can convert a single test case to use the IR, under the new `-use-ir` flag.
Getting this merged into mainline will at least ensure that we keep the IR path working in a minimal fashion, even when we have to add functionality the existing AST-based path

There is definitely some clutter here from keeping both IR-based and AST-based translation around, but I don't want to have a long-lived branch for the IR that gets further and further away from the `master` branch that is actually getting used and tested.

Summary of changes:

- Add pointer types and basic `load` operation to be able to handle variable declarations

- Add basic `call` instruction type

- Add simple address math for field reference in l-value

- Always add IR for referenced decls to global scope

- Add notion of "intrinsic" type modifier, which maps a type declaration directly to an IR opcode (plus optional literal operands to handle things like texture/sampler flavor)

- Improve printing of IR instructions, types, operands

- Add constant-buffer type to IR

- Allow any instruction to be detected as "should be folded into use sites" and use this to tag things of constant-buffer type

- Also add logic for implicit base on member expressions, to handle references to `cbuffer` members

- Add connection back to original decl to IR variables (including global shader parameters...)

- Use reflection name instead of true name when emitting HLSL from IR (so that we can match HLSL output)

- Make IR include decorations for type layout

- Re-use existing emit logic for HLSL semantics to output `register` semantics for IR-based code

- Make IR-based codegen be an option we can enable from the command line
  - It still isn't on by default (it can barely manage a trivial shader), but it seems better to enable it always instead of putting it under an `#ifdef`

- Fix up how we check for intrinsic operations suring AST-based cross compilation so that adding new intrinsic ops for the IR won't break codegen.

1 files changed, 15 insertions, 0 deletions

diff --git a/source/slang/parser.cpp b/source/slang/parser.cpp
index 7da309d29..9c0d692e6 100644
--- a/source/slang/parser.cpp
+++ b/source/slang/parser.cpp
@@ -3916,6 +3916,20 @@ namespace Slang
         return modifier;
     }
 
+    static RefPtr<RefObject> parseIntrinsicTypeModifier(Parser* parser, void* /*userData*/)
+    {
+        RefPtr<IntrinsicTypeModifier> modifier = new IntrinsicTypeModifier();
+        parser->ReadToken(TokenType::LParent);
+        modifier->irOp = uint32_t(StringToInt(parser->ReadToken(TokenType::IntegerLiteral).Content));
+        while( AdvanceIf(parser, TokenType::Comma) )
+        {
+            auto operand = uint32_t(StringToInt(parser->ReadToken(TokenType::IntegerLiteral).Content));
+            modifier->irOperands.Add(operand);
+        }
+        parser->ReadToken(TokenType::RParent);
+
+        return modifier;
+    }
     static RefPtr<RefObject> parseImplicitConversionModifier(Parser* parser, void* /*userData*/)
     {
         RefPtr<ImplicitConversionModifier> modifier = new ImplicitConversionModifier();
@@ -4020,6 +4034,7 @@ namespace Slang
 
         MODIFIER(__builtin_type,    parseBuiltinTypeModifier);
         MODIFIER(__magic_type,      parseMagicTypeModifier);
+        MODIFIER(__intrinsic_type,    parseIntrinsicTypeModifier);
         MODIFIER(__implicit_conversion,     parseImplicitConversionModifier);
 
 #undef MODIFIER