[Mlir-commits] [mlir] [MLIR][NVVM] Add support for converting fp4/6/8 to fp16x2 (PR #162439)

[Srinivasa Ravi]

================
@@ -1855,6 +1855,55 @@ def NVVM_ConvertBF16x2ToF8x2Op : NVVM_Op<"convert.bf16x2.to.f8x2"> {
   }];
 }
 
+class NVVM_ConvertToFP16x2Op_Base <string srcType, Type srcArgType, string dstType>
+: NVVM_Op<"convert." # srcType # "x2.to." # !tolower(dstType) # "x2"> {
+  let summary = "Convert a pair of " # srcType # " inputs to " # !tolower(dstType) # "x2";
+  let description = [{
+    This Op converts the given }] # srcType # [{ inputs in a }] #
+    !if(!eq(srcType, "f4"), "packed i8", "i8x2 vector") # [{ to }] #
+    !tolower(dstType) # [{.
+
+    The result `dst` is represented as a vector of }] # !tolower(dstType) # [{ elements.
+    }] #
+    !if(!eq(dstType, "F16"),
+    [{The `relu` attribute, when set, lowers to the '.relu' variant of 
+    the cvt instruction."}], "") # [{
+    
+    [For more information, see PTX ISA](https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#data-movement-and-conversion-instructions-cvt)
+  }];
+  let results = (outs VectorOfLengthAndType<[2], [!cast<Type>(dstType)]>:$dst);
+  let arguments = !if(!eq(dstType, "F16"),
+    (ins srcArgType:$src,
+         DefaultValuedAttr<BoolAttr, "false">:$relu,
+         TypeAttr:$srcType),
+    (ins srcArgType:$src,
+         TypeAttr:$srcType));
+  let assemblyFormat = "$src attr-dict `:` type($src) `(` $srcType `)` `->` type($dst)";
+  let hasVerifier = 1;
+
+  let extraClassDeclaration = [{
+    static IDArgPair
+    getIntrinsicIDAndArgs(Operation &op, LLVM::ModuleTranslation &mt, 
+                          llvm::IRBuilderBase &builder);
+  }];
+
+  string llvmBuilder = [{
+    auto [intId, args] =
+    NVVM::Convert}] # !toupper(srcType) # [{x2To}] # dstType # 
+      [{x2Op::getIntrinsicIDAndArgs(*op, moduleTranslation, builder);
+    $dst = createIntrinsicCall(builder, intId, args);
+  }];
+}
+
+def NVVM_ConvertF8x2ToF16x2Op :
+  NVVM_ConvertToFP16x2Op_Base<"f8", VectorOfLengthAndType<[2], [I8]>, "F16">;
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Wolfram70 wrote:

Yeah, we'd have to do some string truncation in that case which I think will not be as clean as it currently.

https://github.com/llvm/llvm-project/pull/162439