add SPIR-V GLSL extended Round op

[mravishankar]

Thanks! Can we also add some tests for the operation here and serialization roundtrip tests here. This is in keeping with the procedure to add new op here

[haoyouab]

add tests and serialization roundtrip tests for SPIR-V GLSL Round op

[haoyouab]

Hi, I'm a first-time contributor. Just an ask about the landing/pushing process. Is there anyone who's gonna push this commit for me cause I don't have access?

[antiagainst]

Sure thing. Happy to do that. Thanks for the contribution!

mlir/include/mlir/Dialect/SPIRV/SPIRVGLSLOps.td

let description = [{
     %2 = spv.GLSL.Floor %0 : f32
     %3 = spv.GLSL.Floor %1 : vector<3xf16>
     ```
   }];
 }
 
 // -----
 
+def SPV_GLSLRoundOp: SPV_GLSLUnaryArithmeticOp<"Round", 1, SPV_Float> {
+  let summary = "Rounds to the whole number";
+
+  let description = [{
+    Result is the value equal to the nearest whole number.
+
+    The operand x must be a scalar or vector whose component type is
+    floating-point.
+
+    Result Type and the type of x must be the same type. Results are computed
+    per component.
+
+    <!-- End of AutoGen section -->
+    ```
+    float-scalar-vector-type ::= float-type |
+                                 `vector<` integer-literal `x` float-type `>`
+    floor-op ::= ssa-id `=` `spv.GLSL.Round` ssa-use `:`
+                float-scalar-vector-type
+    ```
+    #### Example:
+
+    ```mlir
+    %2 = spv.GLSL.Round %0 : f32
+    %3 = spv.GLSL.Round %1 : vector<3xf16>
+    ```
+  }];
+}
+
+// -----
+
 def SPV_GLSLInverseSqrtOp : SPV_GLSLUnaryArithmeticOp<"InverseSqrt", 32, SPV_Float> {
   let summary = "Reciprocal of sqrt(operand)";
 
   let description = [{
     Result is the reciprocal of sqrt x. Result is undefined if x <= 0.
 
     The operand x must be a scalar or vector whose component type is
     floating-point.

mlir/test/Dialect/SPIRV/Serialization/glsl-ops.mlir

spv.func @fmul(%arg0 : f32, %arg1 : f32) "None" {
     // CHECK: {{%.*}} = spv.GLSL.Atan {{%.*}} : f32
     %8 = spv.GLSL.Atan %arg0 : f32
     // CHECK: {{%.*}} = spv.GLSL.Sinh {{%.*}} : f32
     %9 = spv.GLSL.Sinh %arg0 : f32
     // CHECK: {{%.*}} = spv.GLSL.Cosh {{%.*}} : f32
     %10 = spv.GLSL.Cosh %arg0 : f32
     // CHECK: {{%.*}} = spv.GLSL.Pow {{%.*}} : f32
     %11 = spv.GLSL.Pow %arg0, %arg1 : f32
+    // CHECK: {{%.*}} = spv.GLSL.Round {{%.*}} : f32
+    %12 = spv.GLSL.Round %arg0 : f32
     spv.Return
   }
 }

mlir/test/Dialect/SPIRV/glslops.mlir

 func @powvec(%arg0 : vector<3xf16>, %arg1 : vector<3xf16>) -> () {
   // CHECK: spv.GLSL.Pow {{%.*}}, {{%.*}} : vector<3xf16>
   %2 = spv.GLSL.Pow %arg0, %arg1 : vector<3xf16>
   return
 }
 
 // -----
 
+//===----------------------------------------------------------------------===//
+// spv.GLSL.Round
+//===----------------------------------------------------------------------===//
+
+func @round(%arg0 : f32) -> () {
+  // CHECK: spv.GLSL.Round {{%.*}} : f32
+  %2 = spv.GLSL.Round %arg0 : f32
+  return
+}
+
+func @roundvec(%arg0 : vector<3xf16>) -> () {
+  // CHECK: spv.GLSL.Round {{%.*}} : vector<3xf16>
+  %2 = spv.GLSL.Round %arg0 : vector<3xf16>
+  return
+}