[llvm-branch-commits] [clang] [llvm] [HLSL][RootSignature] Add parsing of floats for StaticSampler (PR #140181)

[Justin Bogner via llvm-branch-commits]

================
@@ -711,6 +734,35 @@ std::optional<Register> RootSignatureParser::parseRegister() {
   return Reg;
 }
 
+std::optional<float> RootSignatureParser::parseFloatParam() {
+  assert(CurToken.TokKind == TokenKind::pu_equal &&
+         "Expects to only be invoked starting at given keyword");
+  // Consume sign modifier
+  bool Signed =
+      tryConsumeExpectedToken({TokenKind::pu_plus, TokenKind::pu_minus});
+  bool Negated = Signed && CurToken.TokKind == TokenKind::pu_minus;
+
+  // DXC will treat a postive signed integer as unsigned
+  if (!Negated && tryConsumeExpectedToken(TokenKind::int_literal)) {
+    auto UInt = handleUIntLiteral();
+    if (!UInt.has_value())
+      return std::nullopt;
+    return (float)UInt.value();
----------------
bogner wrote:

Better to use a function-style cast (that is, `float(UInt.value())`) rather than a C-style cast here (and later in this function). In general it's better to use C++'s casts over C-style casts, as they're a lot more specific about what types of conversion are expected.

https://github.com/llvm/llvm-project/pull/140181