Fix AVX2 cpuid checks

At the moment test_cpu_runtime_detection_AVX2.cxx is compiled with
-mavx2 to allow it to use the intrinsics; however the compiler jumps
at the chance to use newer instructions outside the actual test;
in my case using AVX in the string manipulation in addTestsToSuite
when my CPU doesn't actually have AVX.

Swing the actual check into a separate file and only compile that
with the extra flag.

We probably need the same change for the SSE* checks as well.

Change-Id: I1683231932fff264a87c96ac95ac1d24b921163a
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/103075
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

3 files changed, 78 insertions, 35 deletions

diff --git a/tools/qa/cppunit/test_cpu_runtime_detection_AVX2.cxx b/tools/qa/cppunit/test_cpu_runtime_detection_AVX2.cxx
index 0c98f2fc8c98..5a3a1ee26638 100644
--- a/tools/qa/cppunit/test_cpu_runtime_detection_AVX2.cxx
+++ b/tools/qa/cppunit/test_cpu_runtime_detection_AVX2.cxx
@@ -8,8 +8,7 @@
  */
 
 #include <tools/simdsupport.hxx>
-
-#ifdef LO_AVX2_AVAILABLE
+#include "test_cpu_runtime_detection_x86_checks.hxx"
 
 #include <cppunit/TestAssert.h>
 #include <cppunit/TestFixture.h>
@@ -23,7 +22,6 @@ namespace
 class CpuRuntimeDetection_AVX2 : public CppUnit::TestFixture
 {
 public:
-    void checkAVX2();
     void testCpuRuntimeDetection();
 
     CPPUNIT_TEST_SUITE(CpuRuntimeDetection_AVX2);
@@ -33,43 +31,13 @@ public:
 
 void CpuRuntimeDetection_AVX2::testCpuRuntimeDetection()
 {
-    // can only run if this function if CPU supports AVX2
+    // can only run this function if CPU supports AVX2
     if (cpuid::isCpuInstructionSetSupported(cpuid::InstructionSetFlags::AVX2))
-        checkAVX2();
-}
-
-void CpuRuntimeDetection_AVX2::checkAVX2()
-{
-    __m256i a = _mm256_set_epi64x(1, 4, 8, 3);
-    __m256i b = _mm256_set_epi64x(2, 1, 1, 5);
-    __m256i c = _mm256_xor_si256(a, b);
-
-    sal_Int64 values[4];
-    _mm256_storeu_si256(reinterpret_cast<__m256i*>(&values), c);
-
-    CPPUNIT_ASSERT_EQUAL(sal_Int64(6), values[0]);
-    CPPUNIT_ASSERT_EQUAL(sal_Int64(9), values[1]);
-    CPPUNIT_ASSERT_EQUAL(sal_Int64(5), values[2]);
-    CPPUNIT_ASSERT_EQUAL(sal_Int64(3), values[3]);
-
-    __m256i d = _mm256_set_epi64x(3, 5, 1, 0);
-
-    __m256i result = _mm256_cmpeq_epi64(d, c);
-
-    // Compare equals
-    sal_Int64 compare[4];
-    _mm256_storeu_si256(reinterpret_cast<__m256i*>(&compare), result);
-
-    CPPUNIT_ASSERT_EQUAL(sal_Int64(0), compare[0]);
-    CPPUNIT_ASSERT_EQUAL(sal_Int64(0), compare[1]);
-    CPPUNIT_ASSERT_EQUAL(sal_Int64(-1), compare[2]);
-    CPPUNIT_ASSERT_EQUAL(sal_Int64(-1), compare[3]);
+        CpuRuntimeDetectionX86Checks::checkAVX2();
 }
 
 CPPUNIT_TEST_SUITE_REGISTRATION(CpuRuntimeDetection_AVX2);
 
 } // end anonymous namespace
 
-#endif
-
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/tools/qa/cppunit/test_cpu_runtime_detection_AVX2_check.cxx b/tools/qa/cppunit/test_cpu_runtime_detection_AVX2_check.cxx
new file mode 100644
index 000000000000..b5948223752c
--- /dev/null
+++ b/tools/qa/cppunit/test_cpu_runtime_detection_AVX2_check.cxx
@@ -0,0 +1,54 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <sal/types.h>
+#include <tools/simdsupport.hxx>
+
+#include <cppunit/TestAssert.h>
+#include <cppunit/TestFixture.h>
+#include <cppunit/extensions/HelperMacros.h>
+#include <cppunit/plugin/TestPlugIn.h>
+
+#include "test_cpu_runtime_detection_x86_checks.hxx"
+
+/* WARNING: This file is compiled with AVX2 support, don't call
+ * any function without checking cpuid to check the CPU can actually
+ * handle it.
+ */
+void CpuRuntimeDetectionX86Checks::checkAVX2()
+{
+#ifdef LO_AVX2_AVAILABLE
+    __m256i a = _mm256_set_epi64x(1, 4, 8, 3);
+    __m256i b = _mm256_set_epi64x(2, 1, 1, 5);
+    __m256i c = _mm256_xor_si256(a, b);
+
+    sal_Int64 values[4];
+    _mm256_storeu_si256(reinterpret_cast<__m256i*>(&values), c);
+
+    CPPUNIT_ASSERT_EQUAL(sal_Int64(6), values[0]);
+    CPPUNIT_ASSERT_EQUAL(sal_Int64(9), values[1]);
+    CPPUNIT_ASSERT_EQUAL(sal_Int64(5), values[2]);
+    CPPUNIT_ASSERT_EQUAL(sal_Int64(3), values[3]);
+
+    __m256i d = _mm256_set_epi64x(3, 5, 1, 0);
+
+    __m256i result = _mm256_cmpeq_epi64(d, c);
+
+    // Compare equals
+    sal_Int64 compare[4];
+    _mm256_storeu_si256(reinterpret_cast<__m256i*>(&compare), result);
+
+    CPPUNIT_ASSERT_EQUAL(sal_Int64(0), compare[0]);
+    CPPUNIT_ASSERT_EQUAL(sal_Int64(0), compare[1]);
+    CPPUNIT_ASSERT_EQUAL(sal_Int64(-1), compare[2]);
+    CPPUNIT_ASSERT_EQUAL(sal_Int64(-1), compare[3]);
+#endif
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/tools/qa/cppunit/test_cpu_runtime_detection_x86_checks.hxx b/tools/qa/cppunit/test_cpu_runtime_detection_x86_checks.hxx
new file mode 100644
index 000000000000..94396bf6285d
--- /dev/null
+++ b/tools/qa/cppunit/test_cpu_runtime_detection_x86_checks.hxx
@@ -0,0 +1,21 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#ifndef INCLUDE_TOOLS_QA_CPPUNIT_TEST_CPU_RUNTIME_DETECTION_X86_CHECKS_H
+#define INCLUDE_TOOLS_QA_CPPUNIT_TEST_CPU_RUNTIME_DETECTION_X86_CHECKS_H
+
+class CpuRuntimeDetectionX86Checks
+{
+public:
+    static void checkAVX2();
+};
+
+#endif
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */