Reland "[mlir] add support for verification in integration tests"

[gysit]

Summary

The patch extends the runner utils by verification methods that compare two memrefs. The methods compare the content of the two memrefs and print success if the data is identical up to a small numerical error. The methods are meant to simplify the development of integration tests that compare the results against a reference implementation (cf. the updates to the linalg matmul integration tests).

Originally landed in 5fa893c (https://reviews.llvm.org/D96326) and reverted in dd719fd due to a Windows build failure.

Changes:

• Remove the max function that requires the "algorithm" header on Windows
• Eliminate the truncation warning in the float specialization of verifyElem by using a float constant

[aartbik]

mlir/include/mlir/ExecutionEngine/RunnerUtils.h

219

Please document what verify means in this case (returning true/false, not verify-failing)

mlir/integration_test/Dialect/Linalg/CPU/benchmark_matmul.mlir

91

did you verify that such a CHECK never has false positives or negatives?
I often see a lot of stray numbers in the output, and just want to make sure this it not too brittle

[gysit]

mlir/integration_test/Dialect/Linalg/CPU/benchmark_matmul.mlir

91

Thank you for the comments.

Are you referring to the numerical aspect of the verification? Or to the single character check?

I verified for a few test cases that I get errors / no errors when I expect them (that's the reason why I introduced the ^ and $). The numerics should be fine for the use cases I have seen so far. The epsilon I chose is quite small compared to the machine epsilon meaning the verification should be sensitive. I believe that is what we want for now.

The best choice for unit testing is of course working with integers. That avoids potential numerical issues.

[aartbik]

mlir/integration_test/Dialect/Linalg/CPU/benchmark_matmul.mlir

91

I was indeed referring to the single character check (just because the output sometimes contains timestamps etc.). I may be overly pedantic but I remember being surprised in the past that a digit-based check actually passed when I did not expect it.

I noticed the ^ and $ so I suspect you gave it some thought, but just wanted to double check. That is why I would prefer some harder check on output (like PASS/FAIL or return code), but if this works, I am fine.

Thanks for confirming.

[gysit]

• address comments aartbik's comments
• return error by value

[gysit]

mlir/integration_test/Dialect/Linalg/CPU/benchmark_matmul.mlir

91

I understand the concern. But actually returning the number of errors is sometimes really useful. E.g. if you may be able to see that the values of one column row are entirely wrong. It is still possible to extend the test with an scf.if error != 0 then printFail to be on the safer side.

[aartbik]

lgtm, perhaps also ask @mehdi_amini to have a quick look, since he is busy refactoring our runner utils

[mehdi_amini]

In general I'm a bit worried that this directory is not well structured, but this addition is in line with the kind of things already in this file so I don't feel like there's a strong reason to hold on this.

[Kayjukh]

mlir/include/mlir/ExecutionEngine/RunnerUtils.h

248

nit: Could be condensed as return (delta <= epsilon * std::abs(expected));

288

This loop "feels wrong" to me because of the two occurrences of the errors variable, even though it seems to be correct when taking the time to think about it. If I'm not mistaken you could remove the errors argument to the function and always start from zero. This line would then become errors += verify(os, ..., strides + 1);, which makes more sense to me.

306

Would it make more sense to return a boolean indicating whether or not there were errors and update a reference argument accordingly? Otherwise, the fact that this function returns -1 if there are no errors should be clearly documented somewhere, as it can easily be overlooked.

[gysit]

• addressed Kayjukh's comments

[gysit]

mlir/include/mlir/ExecutionEngine/RunnerUtils.h

288

True this was confusion. I am now using a separate printCounter passed by reference. Another option would be to return the error count by reference but I currently prefer having a return value on all verify methods.

306

I went for documenting the -1 since I like the additional info provided by the return value.

[Kayjukh]

LGTM. Since @aartbik and @mehdi_amini seem to agree, I think you could land this patch.

mlir/include/mlir/ExecutionEngine/RunnerUtils.h

 #define MLIR_RUNNERUTILS_EXPORT __declspec(dllimport)
 #endif // mlir_runner_utils_EXPORTS
 #endif // MLIR_RUNNERUTILS_EXPORT
 #else
 #define MLIR_RUNNERUTILS_EXPORT
 #endif // _WIN32
 
 #include <assert.h>
+#include <cmath>
 #include <iostream>
 
 #include "mlir/ExecutionEngine/CRunnerUtils.h"
 
 template <typename T, typename StreamType>
 void printMemRefMetaData(StreamType &os, const DynamicMemRefType<T> &V) {
   os << "base@ = " << reinterpret_cast<void *>(V.data) << " rank = " << V.rank
      << " offset = " << V.offset;

 
 ////////////////////////////////////////////////////////////////////////////////
 // Templated instantiation follows.
 ////////////////////////////////////////////////////////////////////////////////
 namespace impl {
 template <typename T, int M, int... Dims>
 std::ostream &operator<<(std::ostream &os, const Vector<T, M, Dims...> &v);
 
-template <int... Dims> struct StaticSizeMult {
+template <int... Dims>
+struct StaticSizeMult {
   static constexpr int value = 1;
 };
 
-template <int N, int... Dims> struct StaticSizeMult<N, Dims...> {
+template <int N, int... Dims>
+struct StaticSizeMult<N, Dims...> {
   static constexpr int value = N * StaticSizeMult<Dims...>::value;
 };
 
 static inline void printSpace(std::ostream &os, int count) {
   for (int i = 0; i < count; ++i) {
     os << ' ';
   }
 }
 
-template <typename T, int M, int... Dims> struct VectorDataPrinter {
+template <typename T, int M, int... Dims>
+struct VectorDataPrinter {
   static void print(std::ostream &os, const Vector<T, M, Dims...> &val);
 };
 
 template <typename T, int M, int... Dims>
 void VectorDataPrinter<T, M, Dims...>::print(std::ostream &os,
                                              const Vector<T, M, Dims...> &val) {
   static_assert(M > 0, "0 dimensioned tensor");
   static_assert(sizeof(val) == M * StaticSizeMult<Dims...>::value * sizeof(T),
void printMemRef(StridedMemRefType<T, N> &M) {
   printMemRef(DynamicMemRefType<T>(M));
 }
 
 template <typename T>
 void printMemRef(UnrankedMemRefType<T> &M) {
   std::cout << "Unranked Memref ";
   printMemRef(DynamicMemRefType<T>(M));
 }
+
+/// Verify the results of two computations are equivalent up to a small
+/// numerical error.
+template <typename T>
+struct MemRefDataVerifier {
+  /// Maximum number of errors printed by the verifier.
+  static constexpr int errorLimit = 10;
+
+  /// Verify the relative difference of the values is smaller than epsilon.
+  static bool verifyRelErrorSmallerThan(T actual, T expected, T epsilon);
+
+  /// Verify the values are equivalent (integers) or are close (floating-point).
+  static bool verifyElem(T actual, T expected);
+
+  /// Verify the data element-by-element.
+  static void verify(std::ostream &os, T *actualBasePtr, T *expectedBasePtr,
+                     int64_t dim, int64_t offset, const int64_t *sizes,
+                     const int64_t *strides, int64_t &errors);
+};
+
+template <typename T>
+bool MemRefDataVerifier<T>::verifyRelErrorSmallerThan(T actual, T expected,
+                                                      T epsilon) {
+  // Return an error if one of the values is infinite or NaN.
+  if (!std::isfinite(actual) || !std::isfinite(expected))
+    return false;
+  // Return true if the relative error is smaller than epsilon.
+  T delta = std::abs(actual - expected);
+  if (delta > epsilon * std::abs(expected))
+    return false;
+  return true;
+}
+
+template <typename T>
+bool MemRefDataVerifier<T>::verifyElem(T actual, T expected) {
+  return actual == expected;
+}
+
+template <>
+inline bool MemRefDataVerifier<double>::verifyElem(double actual,
+                                                   double expected) {
+  return verifyRelErrorSmallerThan(actual, expected, 1e-12);
+}
+
+template <>
+inline bool MemRefDataVerifier<float>::verifyElem(float actual,
+                                                  float expected) {
+  return verifyRelErrorSmallerThan(actual, expected, 1e-6f);
+}
+
+template <typename T>
+void MemRefDataVerifier<T>::verify(std::ostream &os, T *actualBasePtr,
+                                   T *expectedBasePtr, int64_t dim,
+                                   int64_t offset, const int64_t *sizes,
+                                   const int64_t *strides, int64_t &errors) {
+  // Verify the elements at the current offset.
+  if (dim == 0) {
+    if (!verifyElem(actualBasePtr[offset], expectedBasePtr[offset])) {
+      if (errors < errorLimit) {
+        os << actualBasePtr[offset] << " != " << expectedBasePtr[offset]
+           << " offset = " << offset << "\n";
+      } else if (errors == errorLimit) {
+        os << "...\n";
+      }
+      errors++;
+    }
+    return;
+  }
+  // Iterate the current dimension and verify recursively.
+  for (int64_t i = 0; i < sizes[0]; ++i) {
+    verify(os, actualBasePtr, expectedBasePtr, dim - 1, offset + i * strides[0],
+           sizes + 1, strides + 1, errors);
+  }
+}
+
+/// Verify the equivalence of two dynamic memrefs.
+template <typename T>
+int64_t verifyMemRef(const DynamicMemRefType<T> &actual,
+                     const DynamicMemRefType<T> &expected) {
+  // Check the shapes of the MemRefs match.
+  for (int64_t i = 0; i < actual.rank; ++i) {
+    if (expected.rank != actual.rank || actual.offset != expected.offset ||
+        actual.sizes[i] != expected.sizes[i] ||
+        actual.strides[i] != expected.strides[i]) {
+      printMemRefMetaData(std::cerr, actual);
+      printMemRefMetaData(std::cerr, expected);
+      return -1;
+    }
+  }
+  // Count the errors and print the verification result.
+  int64_t errors = 0;
+  MemRefDataVerifier<T>::verify(std::cerr, actual.basePtr, expected.basePtr,
+                                actual.rank, actual.offset, actual.sizes,
+                                actual.strides, errors);
+  return errors;
+}
+
+/// Verify the equivalence of two unranked memrefs.
+template <typename T>
+int64_t verifyMemRef(UnrankedMemRefType<T> &actual,
+                     UnrankedMemRefType<T> &expected) {
+  return verifyMemRef(DynamicMemRefType<T>(actual),
+                      DynamicMemRefType<T>(expected));
+}
+
 } // namespace impl
 
 ////////////////////////////////////////////////////////////////////////////////
 // Currently exposed C API.
 ////////////////////////////////////////////////////////////////////////////////
 extern "C" MLIR_RUNNERUTILS_EXPORT void
 _mlir_ciface_print_memref_i8(UnrankedMemRefType<int8_t> *M);
 extern "C" MLIR_RUNNERUTILS_EXPORT void

 _mlir_ciface_print_memref_3d_f32(StridedMemRefType<float, 3> *M);
 extern "C" MLIR_RUNNERUTILS_EXPORT void
 _mlir_ciface_print_memref_4d_f32(StridedMemRefType<float, 4> *M);
 
 extern "C" MLIR_RUNNERUTILS_EXPORT void
 _mlir_ciface_print_memref_vector_4x4xf32(
     StridedMemRefType<Vector2D<4, 4, float>, 2> *M);
 
+extern "C" MLIR_RUNNERUTILS_EXPORT int64_t _mlir_ciface_verifyMemRefI32(
+    UnrankedMemRefType<int32_t> *actual, UnrankedMemRefType<int32_t> *expected);
+extern "C" MLIR_RUNNERUTILS_EXPORT int64_t _mlir_ciface_verifyMemRefF32(
+    UnrankedMemRefType<float> *actual, UnrankedMemRefType<float> *expected);
+extern "C" MLIR_RUNNERUTILS_EXPORT int64_t _mlir_ciface_verifyMemRefF64(
+    UnrankedMemRefType<double> *actual, UnrankedMemRefType<double> *expected);
+
+extern "C" MLIR_RUNNERUTILS_EXPORT int64_t verifyMemRefI32(int64_t rank,
+                                                           void *actualPtr,
+                                                           void *expectedPtr);
+extern "C" MLIR_RUNNERUTILS_EXPORT int64_t verifyMemRefF32(int64_t rank,
+                                                           void *actualPtr,
+                                                           void *expectedPtr);
+extern "C" MLIR_RUNNERUTILS_EXPORT int64_t verifyMemRefF64(int64_t rank,
+                                                           void *actualPtr,
+                                                           void *expectedPtr);
+
 #endif // EXECUTIONENGINE_RUNNERUTILS_H_

mlir/integration_test/Dialect/Linalg/CPU/benchmark_matmul.mlir

 // RUN: export M=24 && export K=64 && export N=192 && export ITERS=10 && \
 // RUN: cat %s | sed 's@${M}@'"$M"'@g'| sed 's@${K}@'"$K"'@g' | sed 's@${N}@'"$N"'@g'| sed 's@${ITERS}@'"$ITERS"'@g'| \
-// RUN: mlir-opt -test-linalg-codegen-strategy="anchor-op=linalg.matmul register-tile-sizes=12,32,16 vectorize" | \
+// RUN: mlir-opt -test-linalg-codegen-strategy="anchor-func=matmul anchor-op=linalg.matmul register-tile-sizes=12,32,16 vectorize" | \
 // RUN: mlir-opt -test-linalg-codegen-strategy="anchor-op=linalg.fill register-tile-sizes=4,32 vectorize" | \
 // RUN: mlir-opt -test-linalg-codegen-strategy="anchor-op=linalg.copy register-tile-sizes=4,32 vectorize" | \
 
 // RUN: mlir-opt -canonicalize -convert-vector-to-scf -lower-affine -convert-linalg-to-loops | \
 // RUN: mlir-opt -canonicalize -convert-scf-to-std -convert-vector-to-llvm -convert-std-to-llvm | \
 // RUN: mlir-cpu-runner -O3 -e main -entry-point-result=void \
 // Activate to dump assembly
 // R_UN:   -dump-object-file -object-filename=/tmp/a.o \
+// RUN:   -shared-libs=%mlir_integration_test_dir/libmlir_runner_utils%shlibext \
 // RUN:   -shared-libs=%mlir_integration_test_dir/libmlir_c_runner_utils%shlibext | \
 // Use tee to both print to stderr and FileCheck
 // RUN: tee -a /dev/stderr | FileCheck %s
 
 
 !elem_type_a = type f32
 !elem_type_b = type f32
 !elem_type_c = type f32
scf.for %arg0 = %c0 to %iters step %c1 {
     %z = constant 0.0 : !elem_type_c
     linalg.fill(%C, %z) : !row_major_C, !elem_type_c
     call @matmul(%A, %B, %C) : (!row_major_A, !row_major_B, !row_major_C) -> ()
   }
   %t_end_matmul = call @rtclock() : () -> f64
   %tmatmul = subf %t_end_matmul, %t_start_matmul: f64
   call @print_perf(%iters, %tmatmul) : (index, f64) -> ()
 
-  %res = load %C[%c0, %c0]: !row_major_C
-  // CHECK: 64
-  vector.print %res: f32
+  // CHECK: {{^0$}}
+  %C_ref = alloc() : !row_major_C
+  linalg.fill(%C_ref, %v0) : !row_major_C, !elem_type_c
+  linalg.matmul ins(%A, %B : !row_major_A, !row_major_B)
+    outs(%C_ref: !row_major_C)
+  %act = memref_cast %C : !row_major_C to memref<*xf32>
+  %exp = memref_cast %C_ref : !row_major_C to memref<*xf32>
+  %errors = call @verifyMemRefF32(%act, %exp) : (memref<*xf32>, memref<*xf32>) -> i64
+  vector.print %errors : i64
+  dealloc %C_ref : !row_major_C
 
   dealloc %A : !row_major_A
   dealloc %B : !row_major_B
   dealloc %C : !row_major_C
 
   return
 }
 
 func private @rtclock() -> f64
+func private @verifyMemRefF32(memref<*xf32>, memref<*xf32>) -> i64 attributes { llvm.emit_c_interface }
 
 // TODO: init with random, run and check output.
 // func private @fill_random_f32(memref<*xf32>)

mlir/integration_test/Dialect/Linalg/CPU/benchmark_matmul_column_major.mlir

 // RUN: export M=24 && export K=64 && export N=192 && export ITERS=10 && \
 // RUN: cat %s | sed 's@${M}@'"$M"'@g'| sed 's@${K}@'"$K"'@g' | sed 's@${N}@'"$N"'@g'| sed 's@${ITERS}@'"$ITERS"'@g'| \
-// RUN: mlir-opt -test-linalg-codegen-strategy="anchor-op=linalg.matmul_column_major register-tile-sizes=16,0,32 vectorize" | \
+// RUN: mlir-opt -test-linalg-codegen-strategy="anchor-func=matmul_column_major anchor-op=linalg.matmul_column_major register-tile-sizes=16,0,32 vectorize" | \
 // RUN: mlir-opt -test-linalg-codegen-strategy="anchor-op=linalg.fill register-tile-sizes=4,16 vectorize" | \
 
 // TODO: linalg.copy vectorization in the presence of permutation map fails. Enable when addressed.
 // RUN: mlir-opt -test-linalg-codegen-strategy="anchor-op=linalg.copy register-tile-sizes=4,16 vectorize" | \
 
 // RUN: mlir-opt -canonicalize -convert-vector-to-scf -lower-affine -convert-linalg-to-loops | \
 // RUN: mlir-opt -canonicalize -convert-scf-to-std -convert-vector-to-llvm -convert-std-to-llvm | \
 // RUN: mlir-cpu-runner -O3 -e main -entry-point-result=void \
 // Activate to dump assembly
 // R_UN:   -dump-object-file -object-filename=/tmp/a.o \
+// RUN:   -shared-libs=%mlir_integration_test_dir/libmlir_runner_utils%shlibext \
 // RUN:   -shared-libs=%mlir_integration_test_dir/libmlir_c_runner_utils%shlibext | \
 // Use tee to both print to stderr and FileCheck
 // RUN: tee -a /dev/stderr | FileCheck %s
 
 !elem_type_a = type f32
 !elem_type_b = type f32
 !elem_type_c = type f32
 !row_major_A = type memref<${M}x${K}x!elem_type_a>
scf.for %arg0 = %c0 to %iters step %c1 {
     // be easy.
     linalg.fill(%cC, %f0) : !column_major_C, !elem_type_c
     call @matmul_column_major(%cA, %cB, %cC) : (!column_major_A, !column_major_B, !column_major_C) -> ()
   }
   %t_end_matmul_column_major = call @rtclock() : () -> f64
   %tmatmul_column_major = subf %t_end_matmul_column_major, %t_start_matmul_column_major: f64
   call @print_perf(%iters, %tmatmul_column_major) : (index, f64) -> ()
 
-  %res = load %cC[%c0, %c0]: !column_major_C
-  // CHECK: 64
-  vector.print %res: !elem_type_c
+  // CHECK: {{^0$}}
+  %cC_ref = alloc() : !column_major_C
+  linalg.fill(%cC_ref, %f0) : !column_major_C, !elem_type_c
+  linalg.matmul_column_major ins(%cA, %cB : !column_major_A, !column_major_B)
+    outs(%cC_ref: !column_major_C)
+  %act = memref_cast %cC : !column_major_C to memref<*xf32>
+  %exp = memref_cast %cC_ref : !column_major_C to memref<*xf32>
+  %errors = call @verifyMemRefF32(%act, %exp) : (memref<*xf32>, memref<*xf32>) -> i64
+  vector.print %errors : i64
+  dealloc %cC_ref : !column_major_C
 
   dealloc %cA : !column_major_A
   dealloc %cB : !column_major_B
   dealloc %cC : !column_major_C
 
   return
 }
 
 func private @rtclock() -> f64
+func private @verifyMemRefF32(memref<*xf32>, memref<*xf32>) -> i64 attributes { llvm.emit_c_interface }
 
 // TODO: init with random, run and check output.
 // func private @fill_random_f32(memref<*xf32>)

mlir/integration_test/Dialect/Linalg/CPU/benchmark_matmul_column_major_as_row_major.mlir

 // RUN: export M=24 && export K=64 && export N=192 && export ITERS=10 && \
 // RUN: cat %s | sed 's@${M}@'"$M"'@g'| sed 's@${K}@'"$K"'@g' | sed 's@${N}@'"$N"'@g'| sed 's@${ITERS}@'"$ITERS"'@g'| \
-// RUN: mlir-opt -test-linalg-codegen-strategy="anchor-op=linalg.matmul_column_major register-tile-sizes=16,0,32 vectorize" | \
-// RUN: mlir-opt -test-linalg-codegen-strategy="anchor-op=linalg.matmul register-tile-sizes=12,32,16 vectorize" | \
+// RUN: mlir-opt -test-linalg-codegen-strategy="anchor-func=matmul_column_major_as_row_major anchor-op=linalg.matmul_column_major register-tile-sizes=16,0,32 vectorize" | \
+// RUN: mlir-opt -test-linalg-codegen-strategy="anchor-func=matmul_column_major_as_row_major anchor-op=linalg.matmul register-tile-sizes=12,32,16 vectorize" | \
 // RUN: mlir-opt -test-linalg-codegen-strategy="anchor-op=linalg.fill register-tile-sizes=4,16 vectorize" | \
 
 // TODO: linalg.copy vectorization in the presence of permutation map fails. Enable when addressed.
 // R_UN: mlir-opt -test-linalg-codegen-strategy="anchor-op=linalg.copy register-tile-sizes=4,16 vectorize" | \
 
 // RUN: mlir-opt -canonicalize -convert-vector-to-scf -lower-affine -convert-linalg-to-loops | \
 // RUN: mlir-opt -canonicalize -convert-scf-to-std -convert-vector-to-llvm -convert-std-to-llvm | \
 // RUN: mlir-cpu-runner -O3 -e main -entry-point-result=void \
 // Activate to dump assembly
 // R_UN:   -dump-object-file -object-filename=/tmp/a.o \
+// RUN:   -shared-libs=%mlir_integration_test_dir/libmlir_runner_utils%shlibext \
 // RUN:   -shared-libs=%mlir_integration_test_dir/libmlir_c_runner_utils%shlibext | \
 // Use tee to both print to stderr and FileCheck
 // RUN: tee -a /dev/stderr | FileCheck %s
 
 !elem_type_a = type f32
 !elem_type_b = type f32
 !elem_type_c = type f32
 !row_major_A = type memref<${M}x${K}x!elem_type_a>
scf.for %arg0 = %c0 to %iters step %c1 {
     call @matmul_column_major_as_row_major(%cA, %cB, %cC, %A, %B, %C) :
       (!column_major_A, !column_major_B, !column_major_C,
        !row_major_A, !row_major_B, !row_major_C) -> ()
   }
   %t_end_matmul_column_major_as_row_major = call @rtclock() : () -> f64
   %tmatmul_column_major_as_row_major = subf %t_end_matmul_column_major_as_row_major, %t_start_matmul_column_major_as_row_major: f64
   call @print_perf(%iters, %tmatmul_column_major_as_row_major) : (index, f64) -> ()
 
-  %res = load %cC[%c0, %c0]: !column_major_C
-  // CHECK: 64
-  vector.print %res: !elem_type_c
-  %res2 = load %C[%c0, %c0]: !row_major_C
-  // CHECK: 64
-  vector.print %res2: !elem_type_c
+  // CHECK: {{^0$}}
+  %cC_ref = alloc() : !column_major_C
+  linalg.fill(%cC_ref, %f0) : !column_major_C, !elem_type_c
+  linalg.matmul_column_major ins(%cA, %cB : !column_major_A, !column_major_B)
+    outs(%cC_ref: !column_major_C)
+  %act1 = memref_cast %cC : !column_major_C to memref<*xf32>
+  %exp1 = memref_cast %cC_ref : !column_major_C to memref<*xf32>
+  %errors1 = call @verifyMemRefF32(%act1, %exp1) : (memref<*xf32>, memref<*xf32>) -> i64
+  vector.print %errors1 : i64
+  dealloc %cC_ref : !column_major_C
+
+  // CHECK: {{^0$}}
+  %C_ref = alloc() : !row_major_C
+  linalg.fill(%C_ref, %f0) : !row_major_C, !elem_type_c
+  linalg.matmul ins(%A, %B : !row_major_A, !row_major_B)
+    outs(%C_ref: !row_major_C)
+  %act2 = memref_cast %C : !row_major_C to memref<*xf32>
+  %exp2 = memref_cast %C_ref : !row_major_C to memref<*xf32>
+  %errors2 = call @verifyMemRefF32(%act2, %exp2) : (memref<*xf32>, memref<*xf32>) -> i64
+  vector.print %errors2 : i64
+  dealloc %C_ref : !row_major_C
 
   dealloc %A : !row_major_A
   dealloc %B : !row_major_B
   dealloc %C : !row_major_C
 
   dealloc %cA : !column_major_A
   dealloc %cB : !column_major_B
   dealloc %cC : !column_major_C
 
   return
 }
 
 func private @rtclock() -> f64
+func private @verifyMemRefF32(memref<*xf32>, memref<*xf32>) -> i64 attributes { llvm.emit_c_interface }
 
 // TODO: init with random, run and check output.
 // func private @fill_random_f32(memref<*xf32>)

mlir/integration_test/Dialect/Linalg/CPU/benchmark_matmul_i8_i8_i32.mlir

 // RUN: export M=24 && export K=64 && export N=192 && export ITERS=10 && \
 // RUN: cat %s | sed 's@${M}@'"$M"'@g'| sed 's@${K}@'"$K"'@g' | sed 's@${N}@'"$N"'@g'| sed 's@${ITERS}@'"$ITERS"'@g'| \
 // RUN: mlir-opt -test-linalg-codegen-strategy="anchor-func=matmul anchor-op=linalg.matmul_i8_i8_i32 register-tile-sizes=12,32,16 vectorize" | \
 // RUN: mlir-opt -test-linalg-codegen-strategy="anchor-func=matmul anchor-op=linalg.fill register-tile-sizes=4,32 vectorize" | \
 // RUN: mlir-opt -test-linalg-codegen-strategy="anchor-func=matmul anchor-op=linalg.copy register-tile-sizes=4,32 vectorize" | \
 // RUN: mlir-opt -canonicalize -convert-vector-to-scf -lower-affine -convert-linalg-to-loops | \
 
 // RUN: mlir-opt -canonicalize -convert-scf-to-std -convert-vector-to-llvm -convert-std-to-llvm -mlir-disable-threading | \
 // RUN: mlir-cpu-runner -O3 -e main -entry-point-result=void \
 // Activate to dump assembly
 // R_UN:   -dump-object-file -object-filename=/tmp/a.o \
+// RUN:   -shared-libs=%mlir_integration_test_dir/libmlir_runner_utils%shlibext \
 // RUN:   -shared-libs=%mlir_integration_test_dir/libmlir_c_runner_utils%shlibext | \
 // Use tee to both print to stderr and FileCheck
 // RUN: tee -a /dev/stderr | FileCheck %s
 
 
 !elem_type_a = type i8
 !elem_type_b = type i8
 !elem_type_c = type i32
scf.for %arg0 = %c0 to %iters step %c1 {
     // be easy.
     linalg.fill(%C, %v0) : !row_major_C, !elem_type_c
     call @matmul(%A, %B, %C) : (!row_major_A, !row_major_B, !row_major_C) -> ()
   }
   %t_end_matmul = call @rtclock() : () -> f64
   %tmatmul = subf %t_end_matmul, %t_start_matmul: f64
   call @print_perf(%iters, %tmatmul) : (index, f64) -> ()
 
-  %res = load %C[%c0, %c0]: !row_major_C
-  // CHECK: 64
-  vector.print %res: !elem_type_c
+  // CHECK: {{^0$}}
+  %C_ref = alloc() : !row_major_C
+  linalg.fill(%C_ref, %v0) : !row_major_C, !elem_type_c
+  linalg.matmul_i8_i8_i32 ins(%A, %B : !row_major_A, !row_major_B)
+    outs(%C_ref: !row_major_C)
+  %res = memref_cast %C : !row_major_C to memref<*xi32>
+  %exp = memref_cast %C_ref : !row_major_C to memref<*xi32>
+  %errors = call @verifyMemRefI32(%res, %exp) : (memref<*xi32>, memref<*xi32>) -> i64
+  vector.print %errors : i64
+  dealloc %C_ref : !row_major_C
 
   dealloc %A : !row_major_A
   dealloc %B : !row_major_B
   dealloc %C : !row_major_C
 
   return
 }
 
 func private @rtclock() -> f64
+func private @verifyMemRefI32(memref<*xi32>, memref<*xi32>) -> i64 attributes { llvm.emit_c_interface }
 
 // TODO: init with random, run and check output.
 // func private @fill_random_f32(memref<*xf32>)

mlir/lib/ExecutionEngine/RunnerUtils.cpp

 extern "C" void
 _mlir_ciface_print_memref_3d_f32(StridedMemRefType<float, 3> *M) {
   impl::printMemRef(*M);
 }
 extern "C" void
 _mlir_ciface_print_memref_4d_f32(StridedMemRefType<float, 4> *M) {
   impl::printMemRef(*M);
 }
+
+extern "C" int64_t
+_mlir_ciface_verifyMemRefI32(UnrankedMemRefType<int32_t> *actual,
+                             UnrankedMemRefType<int32_t> *expected) {
+  return impl::verifyMemRef(*actual, *expected);
+}
+
+extern "C" int64_t
+_mlir_ciface_verifyMemRefF32(UnrankedMemRefType<float> *actual,
+                             UnrankedMemRefType<float> *expected) {
+  return impl::verifyMemRef(*actual, *expected);
+}
+
+extern "C" int64_t
+_mlir_ciface_verifyMemRefF64(UnrankedMemRefType<double> *actual,
+                             UnrankedMemRefType<double> *expected) {
+  return impl::verifyMemRef(*actual, *expected);
+}
+
+extern "C" int64_t verifyMemRefI32(int64_t rank, void *actualPtr,
+                                   void *expectedPtr) {
+  UnrankedMemRefType<int32_t> actualDesc = {rank, actualPtr};
+  UnrankedMemRefType<int32_t> expectedDesc = {rank, expectedPtr};
+  return _mlir_ciface_verifyMemRefI32(&actualDesc, &expectedDesc);
+}
+
+extern "C" int64_t verifyMemRefF32(int64_t rank, void *actualPtr,
+                                   void *expectedPtr) {
+  UnrankedMemRefType<float> actualDesc = {rank, actualPtr};
+  UnrankedMemRefType<float> expectedDesc = {rank, expectedPtr};
+  return _mlir_ciface_verifyMemRefF32(&actualDesc, &expectedDesc);
+}
+
+extern "C" int64_t verifyMemRefF64(int64_t rank, void *actualPtr,
+                                   void *expectedPtr) {
+  UnrankedMemRefType<double> actualDesc = {rank, actualPtr};
+  UnrankedMemRefType<double> expectedDesc = {rank, expectedPtr};
+  return _mlir_ciface_verifyMemRefF64(&actualDesc, &expectedDesc);
+}