[mlir][spirv] Enable validation of selection and phi tests (#166794)

Some of the test cases are failing as they introduce unstructured
control flow. It would be good to catch this in MLIR, but I am not sure
it is currently feasible. We could enforce the conditional branch to
always be in `spirv.mlir.selection` however from my perspective it will
break our downstream project as we rely on unstructured control flow,
i.e., the control flow graph is structured but we do not use
`spirv.mlir.selection` and `spirv.mlir.loop` as they do not currently
support early exists. It seems that the support for early exists is
slowly coming into MLIR so we probably can revise what is being enforced
regarding control flow ops in the future.

Author: IgWod-IMG

mlir/test/Target/SPIRV/phi.mlir

@@ -1,5 +1,10 @@
 // RUN: mlir-translate -no-implicit-module -split-input-file -test-spirv-roundtrip %s | FileCheck %s
 
+// RUN: %if spirv-tools %{ rm -rf %t %}
+// RUN: %if spirv-tools %{ mkdir %t %}
+// RUN: %if spirv-tools %{ mlir-translate --no-implicit-module --serialize-spirv --split-input-file --spirv-save-validation-files-with-prefix=%t/module %s %}
+// RUN: %if spirv-tools %{ spirv-val %t %}
+
 // Test branch with one block argument
 
 spirv.module Logical GLSL450 requires #spirv.vce<v1.0, [Shader], []> {
@@ -295,15 +300,26 @@ spirv.module Logical GLSL450 requires #spirv.vce<v1.0, [Shader], []> {
     %true = spirv.Constant true
     %zero = spirv.Constant 0 : i32
     %one = spirv.Constant 1 : i32
+    spirv.mlir.selection {
 // CHECK:   spirv.BranchConditional %{{.*}}, ^[[true1:.*]](%{{.*}}, %{{.*}} : i32, i32), ^[[false1:.*]]
-    spirv.BranchConditional %true, ^true1(%zero, %zero: i32, i32), ^false1
+      spirv.BranchConditional %true, ^true1(%zero, %zero: i32, i32), ^false1
 // CHECK: [[true1]](%{{.*}}: i32, %{{.*}}: i32)
-  ^true1(%arg0: i32, %arg1: i32):
-    spirv.Return
+    ^true1(%arg0: i32, %arg1: i32):
+      spirv.Return
 // CHECK: [[false1]]:
-  ^false1:
+    ^false1:
+      spirv.Return
+    ^merge:
+      spirv.mlir.merge
+    }
+
+    spirv.Return
+  }
+
+  spirv.func @main() -> () "None" {
     spirv.Return
   }
+  spirv.EntryPoint "GLCompute" @main
 }
 
 // -----
@@ -314,15 +330,26 @@ spirv.module Logical GLSL450 requires #spirv.vce<v1.0, [Shader], []> {
     %true = spirv.Constant true
     %zero = spirv.Constant 0 : i32
     %one = spirv.Constant 1 : i32
+    spirv.mlir.selection {
 // CHECK:   spirv.BranchConditional %{{.*}}, ^[[true1:.*]], ^[[false1:.*]](%{{.*}}, %{{.*}} : i32, i32)
-    spirv.BranchConditional %true, ^true1, ^false1(%zero, %zero: i32, i32)
+      spirv.BranchConditional %true, ^true1, ^false1(%zero, %zero: i32, i32)
 // CHECK: [[true1]]:
-  ^true1:
-    spirv.Return
+    ^true1:
+      spirv.Return
 // CHECK: [[false1]](%{{.*}}: i32, %{{.*}}: i32):
-  ^false1(%arg0: i32, %arg1: i32):
+    ^false1(%arg0: i32, %arg1: i32):
+      spirv.Return
+    ^merge:
+      spirv.mlir.merge
+    }
+
+    spirv.Return
+  }
+
+  spirv.func @main() -> () "None" {
     spirv.Return
   }
+  spirv.EntryPoint "GLCompute" @main
 }
 
 // -----
@@ -333,13 +360,24 @@ spirv.module Logical GLSL450 requires #spirv.vce<v1.0, [Shader], []> {
     %true = spirv.Constant true
     %zero = spirv.Constant 0 : i32
     %one = spirv.Constant 1 : i32
+    spirv.mlir.selection {
 // CHECK:   spirv.BranchConditional %{{.*}}, ^[[true1:.*]](%{{.*}} : i32), ^[[false1:.*]](%{{.*}}, %{{.*}} : i32, i32)
-    spirv.BranchConditional %true, ^true1(%one: i32), ^false1(%zero, %zero: i32, i32)
+      spirv.BranchConditional %true, ^true1(%one: i32), ^false1(%zero, %zero: i32, i32)
 // CHECK: [[true1]](%{{.*}}: i32):
-  ^true1(%arg0: i32):
-    spirv.Return
+    ^true1(%arg0: i32):
+      spirv.Return
 // CHECK: [[false1]](%{{.*}}: i32, %{{.*}}: i32):
-  ^false1(%arg1: i32, %arg2: i32):
+    ^false1(%arg1: i32, %arg2: i32):
+      spirv.Return
+    ^merge:
+      spirv.mlir.merge
+    }
+
     spirv.Return
   }
+
+  spirv.func @main() -> () "None" {
+    spirv.Return
+  }
+  spirv.EntryPoint "GLCompute" @main
 }

mlir/test/Target/SPIRV/selection.mlir

@@ -1,5 +1,10 @@
 // RUN: mlir-translate -no-implicit-module -test-spirv-roundtrip -split-input-file %s | FileCheck %s
 
+// RUN: %if spirv-tools %{ rm -rf %t %}
+// RUN: %if spirv-tools %{ mkdir %t %}
+// RUN: %if spirv-tools %{ mlir-translate --no-implicit-module --serialize-spirv --split-input-file --spirv-save-validation-files-with-prefix=%t/module %s %}
+// RUN: %if spirv-tools %{ spirv-val %t %}
+
 // Selection with both then and else branches
 
 spirv.module Logical GLSL450 requires #spirv.vce<v1.0, [Shader], []> {
@@ -136,19 +141,31 @@ spirv.module Logical GLSL450 requires #spirv.vce<v1.0, [Shader], []> {
 
 // CHECK-NEXT:    spirv.Load "Function" %[[VAR]]
     %cond = spirv.Load "Function" %var : i1
+    spirv.mlir.selection {
 //      CHECK:    spirv.BranchConditional %1, ^[[THEN1:.+]](%{{.+}} : i32), ^[[ELSE1:.+]](%{{.+}}, %{{.+}} : i32, i32)
-    spirv.BranchConditional %cond, ^then1(%one: i32), ^else1(%zero, %zero: i32, i32)
+      spirv.BranchConditional %cond, ^then1(%one: i32), ^else1(%zero, %zero: i32, i32)
 
 // CHECK-NEXT:  ^[[THEN1]](%{{.+}}: i32):
 // CHECK-NEXT:    spirv.Return
-  ^then1(%arg0: i32):
-    spirv.Return
+    ^then1(%arg0: i32):
+      spirv.Return
 
 // CHECK-NEXT:  ^[[ELSE1]](%{{.+}}: i32, %{{.+}}: i32):
 // CHECK-NEXT:    spirv.Return
-  ^else1(%arg1: i32, %arg2: i32):
+    ^else1(%arg1: i32, %arg2: i32):
+      spirv.Return
+    ^merge:
+      spirv.mlir.merge
+    }
+
     spirv.Return
   }
+
+  spirv.func @main() -> () "None" {
+    spirv.Return
+  }
+  spirv.EntryPoint "GLCompute" @main
+  spirv.ExecutionMode @main "LocalSize", 1, 1, 1
 }
 
 // -----