[Mlir-commits] [mlir] [mlir][emitc] Add 'emitc.switch' op to the dialect (PR #102331)

[Simon Camphausen]

================
@@ -1302,5 +1302,86 @@ def EmitC_SubscriptOp : EmitC_Op<"subscript", []> {
   let assemblyFormat = "$value `[` $indices `]` attr-dict `:` functional-type(operands, results)";
 }
 
+def EmitC_SwitchOp : EmitC_Op<"switch", [RecursiveMemoryEffects,
+    SingleBlockImplicitTerminator<"emitc::YieldOp">,
+    DeclareOpInterfaceMethods<RegionBranchOpInterface,
+                              ["getRegionInvocationBounds",
+                               "getEntrySuccessorRegions"]>]> {
+  let summary = "Switch operation";
+  let description = [{
+    The `emitc.switch` is a control-flow operation that branches to one of
+    the given regions based on the values of the argument and the cases.
+    The operand to a switch operation is a opaque, integral or pointer
+    wide types.
+
+    The operation always has a "default" region and any number of case regions
+    denoted by integer constants. Control-flow transfers to the case region
+    whose constant value equals the value of the argument. If the argument does
+    not equal any of the case values, control-flow transfer to the "default"
+    region.
+
+    The operation does not return any value. Moreover, case regions must be
+    explicitly terminated using the `emitc.yield` operation. Default region is
+    yielded implicitly.
+
+    Example:
+
+    ```mlir
+    // Example:
+    emitc.switch %0 : i32
+    case 2: {
+      %1 = emitc.call_opaque "func_b" () : () -> i32
+      emitc.yield
+    }
+    case 5: {
+      %2 = emitc.call_opaque "func_a" () : () -> i32
+      emitc.yield
+    }
+    default: {
+      %3 = "emitc.variable"(){value = 42.0 : f32} : () -> f32
+      emitc.call_opaque "func2" (%3) : (f32) -> ()
+    }
+
+    // Output:
+    switch (v1) {
+    case (2): {
+      int32_t v2 = func_b();
+      break;
+    }
+    case (5): {
----------------
simon-camp wrote:

nit: Remove the parentheses around the case values.

https://github.com/llvm/llvm-project/pull/102331