Implement non member function atomic texture support (#4544)

* Implement non member function atomic texture support texture_buffer and texture1d

Fixes: #4538
Related to: #4291, fixes `tests/compute/atomics-buffer.slang`

Texture objects cannot use `__getMetalAtomicRef` to cast objects into atomic value type. [Texture objects mandate use of member functions](https://developer.apple.com/metal/Metal-Shading-Language-Specification.pdf#Texture%20Functions). The implementation is as follows:
* We can detect texture object usage through checking for an `IRImageSubscript` Operation. `__isTextureAccess()` was added to evaluate if we have an `IRImageSubscript` operation at compile time (before `static_assert`). `__isTextureAccess()` only checks if we are targeting Metal.
* We have all parameter data needed to call a texture atomic function embedded inside `IRImageSubscript`. `__extractTextureFromTextureAccess()` and `__extractCoordFromTextureAccess()` was added to extract this data for use with Metal atomics.

Note:
* Metal documentation has various incorrect details (function names)
* Since we currently hardcode metal versions for compiling, the Metal compiler version was changed to target `Metal 3.1` (`slang-gcc-compiler-util.cpp`)
* textures do not permit atomic float operations

* add fallthrough attribute + fix bug with 'exchange instead of xor' + fix warning bug

* incorrect function name fix

* missing filecheck

* disable atomics-buffer.slang compute test since GFX issue causing it to fail

* Array support for metal interlockedAtomic and proper verification of texture with interlockedAtomic functions

* Array support for metal interlockedAtomic
* proper verification of texture with interlockedAtomic functions
note: had to seperate many functions to allow forceInlining to run

* missing getOperand(0)

* push atomic fix for metal

* fix atomic syntax for metal and hlsl emitting extra brackets (breaks tests)

* test changes and meta changes

1. max is 8 rw textures with metal because Metal has this limit. Split up tests to not hit this limit
2. added back `[0]`...,`T` to test since this legalizes metal atomic intrinsic

* macro'ify some of the atomic code

1. addresses review
2. makes code easier to modify in the future (rather than sifting through 1000 lines we can just look at ~10-30

* fix test 'check'

* missing float support due to macro

* add functions macro generates, `InternalAtomicOperationInfo`

---------

Co-authored-by: Yong He <yonghe@outlook.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/source/slang/slang-emit-c-like.cpp b/source/slang/slang-emit-c-like.cpp
index 66ee12ca6..7ce2c7900 100644
--- a/source/slang/slang-emit-c-like.cpp
+++ b/source/slang/slang-emit-c-like.cpp
@@ -2566,10 +2566,15 @@ void CLikeSourceEmitter::defaultEmitInstExpr(IRInst* inst, const EmitOpInfo& inO
         emitOperand(inst->getOperand(1), rightSide(outerPrec, prec));
         break;
     }
+
+    case kIROp_ImageSubscript:
+        // We should have legalized ImageSubscript before emit for metal targets
+        if (isMetalTarget(this->getTargetReq()))
+            getSink()->diagnose(inst, Diagnostics::unimplemented, "kIROp_ImageSubscript is unimplemented for Metal, expected legalization beforehand");
+        [[fallthrough]];
     case kIROp_GetElement:
     case kIROp_MeshOutputRef:
     case kIROp_GetElementPtr:
-    case kIROp_ImageSubscript:
         // HACK: deal with translation of GLSL geometry shader input arrays.
         if(auto decoration = inst->getOperand(0)->findDecoration<IRGLSLOuterArrayDecoration>())
         {