[mlir] Fix unused-variable warnings

This patch fixes warnings of the form:

  mlir/lib/Conversion/VectorToGPU/VectorToGPU.cpp:320:19: error:
  unused variable 'result' [-Werror,-Wunused-variable]

Author: kazutakahirata

mlir/include/mlir/Query/Matcher/SliceMatchers.h

@@ -114,6 +114,7 @@ bool BackwardSliceMatcher<Matcher>::matches(
   };
   LogicalResult result = getBackwardSlice(rootOp, &backwardSlice, options);
   assert(result.succeeded() && "expected backward slice to succeed");
+  (void)result;
   return options.inclusive ? backwardSlice.size() > 1
                            : backwardSlice.size() >= 1;
 }

mlir/lib/Analysis/SliceAnalysis.cpp

@@ -180,6 +180,7 @@ mlir::getSlice(Operation *op, const BackwardSliceOptions &backwardSliceOptions,
     LogicalResult result =
         getBackwardSlice(currentOp, &backwardSlice, backwardSliceOptions);
     assert(result.succeeded());
+    (void)result;
     slice.insert_range(backwardSlice);
 
     // Compute and insert the forwardSlice starting from currentOp.
@@ -204,6 +205,7 @@ static bool dependsOnCarriedVals(Value value,
   };
   LogicalResult result = getBackwardSlice(value, &slice, sliceOptions);
   assert(result.succeeded());
+  (void)result;
 
   // Check that none of the operands of the operations in the backward slice are
   // loop iteration arguments, and neither is the value itself.

mlir/lib/Conversion/VectorToGPU/VectorToGPU.cpp

@@ -320,6 +320,7 @@ getSliceContract(Operation *op,
     LogicalResult result =
         getBackwardSlice(currentOp, &backwardSlice, backwardSliceOptions);
     assert(result.succeeded() && "expected a backward slice");
+    (void)result;
     slice.insert_range(backwardSlice);
 
     // Compute and insert the forwardSlice starting from currentOp.

mlir/lib/Dialect/Linalg/Transforms/HoistPadding.cpp

@@ -126,11 +126,13 @@ static void computeBackwardSlice(tensor::PadOp padOp,
   for (Value v : valuesDefinedAbove) {
     LogicalResult result = getBackwardSlice(v, &backwardSlice, sliceOptions);
     assert(result.succeeded() && "expected a backward slice");
+    (void)result;
   }
   // Then, add the backward slice from padOp itself.
   LogicalResult result =
       getBackwardSlice(padOp.getOperation(), &backwardSlice, sliceOptions);
   assert(result.succeeded() && "expected a backward slice");
+  (void)result;
 }
 
 //===----------------------------------------------------------------------===//

mlir/lib/Dialect/NVGPU/TransformOps/NVGPUTransformOps.cpp

@@ -293,6 +293,7 @@ static void getPipelineStages(
     if (stage0Ops.contains(&op)) {
       LogicalResult result = getBackwardSlice(&op, &dependencies, options);
       assert(result.succeeded() && "expected a backward slice");
+      (void)result;
     }
   }
 

mlir/lib/Dialect/SCF/Transforms/TileUsingInterface.cpp

@@ -1774,6 +1774,7 @@ checkAssumptionForLoop(Operation *loopOp, Operation *consumerOp,
   for (auto operand : consumerOp->getOperands()) {
     LogicalResult result = getBackwardSlice(operand, &slice, options);
     assert(result.succeeded() && "expected a backward slice");
+    (void)result;
   }
 
   if (!slice.empty()) {

mlir/lib/Transforms/Utils/RegionUtils.cpp

@@ -1096,6 +1096,7 @@ LogicalResult mlir::moveOperationDependencies(RewriterBase &rewriter,
   llvm::SetVector<Operation *> slice;
   LogicalResult result = getBackwardSlice(op, &slice, options);
   assert(result.succeeded() && "expected a backward slice");
+  (void)result;
 
   // If the slice contains `insertionPoint` cannot move the dependencies.
   if (slice.contains(insertionPoint)) {
@@ -1162,6 +1163,7 @@ LogicalResult mlir::moveValueDefinitions(RewriterBase &rewriter,
   for (auto value : prunedValues) {
     LogicalResult result = getBackwardSlice(value, &slice, options);
     assert(result.succeeded() && "expected a backward slice");
+    (void)result;
   }
 
   // If the slice contains `insertionPoint` cannot move the dependencies.

mlir/test/lib/Dialect/Affine/TestVectorizationUtils.cpp

@@ -157,6 +157,7 @@ void VectorizerTestPass::testBackwardSlicing(llvm::raw_ostream &outs) {
     LogicalResult result =
         getBackwardSlice(m.getMatchedOperation(), &backwardSlice);
     assert(result.succeeded() && "expected a backward slice");
+    (void)result;
     outs << "\nmatched: " << *m.getMatchedOperation()
          << " backward static slice: ";
     for (auto *op : backwardSlice)

mlir/test/lib/IR/TestSlicing.cpp

@@ -43,6 +43,7 @@ static LogicalResult createBackwardSliceFunction(Operation *op,
   options.omitUsesFromAbove = false;
   LogicalResult result = getBackwardSlice(op, &slice, options);
   assert(result.succeeded() && "expected a backward slice");
+  (void)result;
   for (Operation *slicedOp : slice)
     builder.clone(*slicedOp, mapper);
   builder.create<func::ReturnOp>(loc);