[MLIR][NVVM] Add lg2.approx.f and lg2.approx.ftz.f ops to NVVM dialect

Author: SwarnaDharshiniS

mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td

@@ -449,7 +449,7 @@ def NVVM_RcpApproxFtzF32Op : NVVM_IntrOp<"rcp.approx.ftz.f", [Pure], 1> {
   let assemblyFormat = "$arg attr-dict `:` type($res)";
 }
 
-def NVVM_ex2ApproxFtzF32Op : NVVM_IntrOp<"ex2.approx.ftz.f", [Pure], 1> {
+def NVVM_lg2ApproxF32Op : NVVM_IntrOp<"lg2.approx.f", [Pure], 1> {
   let arguments = (ins F32:$arg);
   let results = (outs F32:$res);
   let assemblyFormat = "$arg attr-dict `:` type($res)";

mlir/test/Dialect/LLVMIR/nvvm.mlir

@@ -36,15 +36,15 @@ func.func @nvvm_rcp(%arg0: f32) -> f32 {
   llvm.return %0 : f32
 }
 
-// CHECK-LABEL: @nvvm_ex2
-func.func @nvvm_ex2(%arg0: f32) -> f32 {
-  // CHECK: nvvm.ex2.approx.ftz.f %arg0 : f32
-  %0 = nvvm.ex2.approx.ftz.f %arg0 : f32
+// CHECK-LABEL: @nvvm_lg2_f32
+func.func @nvvm_lg2_f32(%arg0: f32) -> f32 {
+  // CHECK: nvvm.lg2.approx.f %arg0 : f32
+  %0 = nvvm.lg2.approx.f %arg0 : f32
   llvm.return %0 : f32
 }
 
-// CHECK-LABEL: @nvvm_lg2
-func.func @nvvm_lg2(%arg0: f32) -> f32 {
+// CHECK-LABEL: @nvvm_lg2_ftz_f32
+func.func @nvvm_lg2_ftz_f32(%arg0: f32) -> f32 {
   // CHECK: nvvm.lg2.approx.ftz.f %arg0 : f32
   %0 = nvvm.lg2.approx.ftz.f %arg0 : f32
   llvm.return %0 : f32