[clang] [llvm] [HLSL][DXIL][SPIRV] Create llvm dot intrinsic and use for HLSL (PR #102872)

[Greg Roth via cfe-commits]

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@@ -18470,22 +18470,14 @@ llvm::Value *CodeGenFunction::EmitScalarOrConstFoldImmArg(unsigned ICEArguments,
   return Arg;
 }
 
-Intrinsic::ID getDotProductIntrinsic(QualType QT, int elementCount) {
-  if (QT->hasFloatingRepresentation()) {
-    switch (elementCount) {
-    case 2:
-      return Intrinsic::dx_dot2;
-    case 3:
-      return Intrinsic::dx_dot3;
-    case 4:
-      return Intrinsic::dx_dot4;
-    }
-  }
-  if (QT->hasSignedIntegerRepresentation())
-    return Intrinsic::dx_sdot;
-
-  assert(QT->hasUnsignedIntegerRepresentation());
-  return Intrinsic::dx_udot;
+// Return dot product intrinsic that corresponds to the QT scalar type
+Intrinsic::ID getDotProductIntrinsic(QualType QT) {
+  if (QT->isFloatingType())
+    return Intrinsic::fdot;
+  if (QT->isSignedIntegerType())
+    return Intrinsic::sdot;
----------------
pow2clk wrote:

Justin's proposal didn't say explicitly, but linked to the [HLSL documentation ](https://learn.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-dot), which explicitly includes integers. In the discussion, there was an [explicit request](https://discourse.llvm.org/t/rfc-all-the-math-intrinsics/78294/3) for integer versions that no one disapproved of there. 

https://github.com/llvm/llvm-project/pull/102872