From ad3539574f52634c51523cfec1747e7565ad8876 Mon Sep 17 00:00:00 2001 From: Tim Foley Date: Wed, 6 Sep 2017 14:56:28 -0700 Subject: Replace old notion of "intrinsic" operations The code previously had an enumerated type for "intrinsic" operations, and allowed functions to be marked `__intrinsic_op(...)` to indicate the operation they map to. The nature of the IR meant that each of these intrinsic ops had to have a corresponding IR opcode, but the `enum` types weren't the same. This change cleans things up a bit by deciding that the `__intrinsic_op(...)` modifier names an actual IR opcode, and so the `IntrinsicOp` enum is gone. The biggest source of complexity here is that there are certain operations that need to be "intrinsic"-ish for the purposes of the current AST-based translation path, because we need them to round-trip from source to AST and back. Right now this is being handled by defining a bunch of "pseudo-ops" which can be used in the `__intrinsic_op` modifier, but which are *not* meant to be represented in the IR. Currently I don't actually handle this during IR generation. In the long run, once we are using IR for everything that needs cross-compilation, we should be able to eliminate the pseudo-ops in favor of just having these be ordinary (inline) functions defined in the stdlib (e.g., the `+=` operator can just have a direct definition). There was a second category of modifier that gets a little caught up in this, which is the `__intrinsic` modifier, which got used in two ways: 1. A function marked `__intrinsic(glsl, ...)` had what I call a "target intrinsic" modifier, which specified how to lower it for a specific target (e.g., GLSL). 2. A function just marked `__intrinsic` was supposed to be a marker for "this function shouldn't be emitted in the output, because the implementation is expected to be provided" The latter category of function should really be an `__intrinsic_op`, so I translated all those uses. I added a tiny bit of sugar so that `__intrinsic_op` without an explicit opcode will look up an opcode based on the name of the function being called, so that an operation like `sin` can automatically be plumbed through to an equivalent IR op. (The first category is a stopgap for the AST-based cross-compilation, and will hopefully be replaced by something better as we get the IR-based path working). Getting the switch from `__intrinsic` to `__intrinsic_op` working required shuffling around some code in `emit.cpp` that handles looking up those modifiers and emitting builtin operations appropriately during cross-compilation. Depending on where we go with things, a possible extension of this approach is to allow multiple operands to `__intrinsic_op` so that the first specifies the opcode, and then the rest are literal arguments to specify "sub-ops." This could help us handle stuff like texture-fetch operations without an explosion in the number of opcodes. I still need to think about whether this is a good idea or not. --- source/slang/modifier-defs.h | 34 +++++++++++++++------------------- 1 file changed, 15 insertions(+), 19 deletions(-) (limited to 'source/slang/modifier-defs.h') diff --git a/source/slang/modifier-defs.h b/source/slang/modifier-defs.h index d7d0391e4..9a16a0bdd 100644 --- a/source/slang/modifier-defs.h +++ b/source/slang/modifier-defs.h @@ -25,32 +25,28 @@ SIMPLE_MODIFIER(Exported); #undef SIMPLE_MODIFIER -// Base class for modifiers that mark something as "intrinsic" -// and thus lacking a direct implementation in the language. -ABSTRACT_SYNTAX_CLASS(IntrinsicModifierBase, Modifier) -END_SYNTAX_CLASS() - -// A modifier that marks something as one of a small set of -// truly intrinsic operations that the compiler knows about -// directly. -SYNTAX_CLASS(IntrinsicOpModifier, IntrinsicModifierBase) +// A modifier that marks something as an operation that +// has a one-to-one translation to the IR, and thus +// has no direct definition in the high-level language. +// +SYNTAX_CLASS(IntrinsicOpModifier, Modifier) -// token that names the intrinsic op -FIELD(Token, opToken) + // token that names the intrinsic op + FIELD(Token, opToken) -// The opcode for the intrinsic operation -FIELD_INIT(IntrinsicOp, op, IntrinsicOp::Unknown) + // The opcode for the intrinsic operation + FIELD_INIT(IROp, op, kIROp_Nop) END_SYNTAX_CLASS() // A modifier that marks something as an intrinsic function, // for some subset of targets. -SYNTAX_CLASS(TargetIntrinsicModifier, IntrinsicModifierBase) -// Token that names the target that the operation -// is an intrisic for. -FIELD(Token, targetToken) +SYNTAX_CLASS(TargetIntrinsicModifier, Modifier) + // Token that names the target that the operation + // is an intrisic for. + FIELD(Token, targetToken) -// A custom definition for the operation -FIELD(Token, definitionToken) + // A custom definition for the operation + FIELD(Token, definitionToken) END_SYNTAX_CLASS() // A modifier to tag something as an intrinsic that requires -- cgit v1.2.3