[llvm-branch-commits] [DirectX] Add resource handling to the DXIL pretty printer (PR #104448)

[Justin Bogner via llvm-branch-commits]

================
@@ -10,23 +10,235 @@
 #include "DXILResourceAnalysis.h"
 #include "DirectX.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/Analysis/DXILResource.h"
 #include "llvm/IR/PassManager.h"
+#include "llvm/InitializePasses.h"
 #include "llvm/Pass.h"
+#include "llvm/Support/FormatAdapters.h"
 #include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
 
-static void prettyPrintResources(raw_ostream &OS,
+static constexpr StringRef getRCName(dxil::ResourceClass RC) {
----------------
bogner wrote:

This generates noticeably worse code because of the hash table lookup and also introduces a static initializer, which should really be avoided. It is possible to do something similar with a static table, but you need to break the abstraction of the enum a bit to do that and adding static asserts to make sure it's correct undoes most of the potential clarity it adds.

I suppose we could do something like this to couple the names, but I'm not entirely sold that the usability hit is worth it:
```c++
struct ResourceClassNameInfo {
  const StringRef Name;
  const StringRef Prefix;
};

static constexpr ResourceClassNameInfo getRCNameInfo(dxil::ResourceClass RC) {
  switch (RC) {
  case dxil::ResourceClass::SRV:
    return {"SRV", "t"};
  case dxil::ResourceClass::UAV:
    return {"UAV", "u"};
  case dxil::ResourceClass::CBuffer:
    return {"cbuffer", "cb"};
  case dxil::ResourceClass::Sampler:
    return {"sampler", "s"};
  }
  llvm_unreachable("covered switch");
}
```

https://github.com/llvm/llvm-project/pull/104448