diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1910b490..bb929106 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -236,18 +236,17 @@ foreach(flag ${Vc_ARCHITECTURE_FLAGS})
 endforeach()
 
 # add definition as expected in src/arch/simddetect.cpp
-set(AVX_OPT OFF)
-set(AVX2_OPT OFF)
-set(FMA_OPT OFF)
-set(SSE41_OPT OFF)
+set(HAVE_AVX OFF)
+set(HAVE_AVX2 OFF)
+set(HAVE_FMA OFF)
+set(HAVE_SSE4_1 OFF)
 set(MARCH_NATIVE_OPT OFF)
 foreach(flag ${_enable_vector_unit_list})  # from OptimizeForArchitecture()
     string(TOUPPER "${flag}" flag)
     string(REPLACE "\." "_" flag "${flag}")
-    set(simd_flags "${simd_flags} -D${flag}")
-    string(REPLACE "_" "" flag "${flag}")
-    if("${flag}" MATCHES "AVX|AVX2|FMA|SSE41")
-        set("${flag}_OPT" ON)
+    if("${flag}" MATCHES "AVX|AVX2|FMA|SSE4_1")
+        set(simd_flags "${simd_flags} -DHAVE_${flag}")
+        set("HAVE_${flag}" ON)
     endif()
 endforeach(flag)
 if (NOT MSVC)
@@ -306,10 +305,10 @@ message( STATUS "Linker options: ${CMAKE_EXE_LINKER_FLAGS} ${CMAKE_EXE_LINKER_FL
 message( STATUS "Install directory: ${CMAKE_INSTALL_PREFIX}")
 message( STATUS "Architecture flags: ${Vc_ARCHITECTURE_FLAGS}")
 message( STATUS "Vector unit list: ${_enable_vector_unit_list}")
-message( STATUS "AVX_OPT: ${AVX_OPT}")
-message( STATUS "AVX2_OPT: ${AVX2_OPT}")
-message( STATUS "FMA_OPT: ${FMA_OPT}")
-message( STATUS "SSE41_OPT: ${SSE41_OPT}")
+message( STATUS "HAVE_AVX: ${HAVE_AVX}")
+message( STATUS "HAVE_AVX2: ${HAVE_AVX2}")
+message( STATUS "HAVE_FMA: ${HAVE_FMA}")
+message( STATUS "HAVE_SSE4_1: ${HAVE_SSE4_1}")
 message( STATUS "MARCH_NATIVE_OPT: ${MARCH_NATIVE_OPT}")
 message( STATUS "simd_flags: ${simd_flags}")
 message( STATUS "--------------------------------------------------------")
@@ -383,22 +382,22 @@ list(APPEND arch_files
 )
 set_source_files_properties(${arch_files} PROPERTIES COMPILE_FLAGS "${simd_flags}")
 set_source_files_properties(src/arch/dotproduct.cpp PROPERTIES COMPILE_FLAGS "${MARCH_NATIVE_FLAGS} ${Vc_CXX_FLAGS}")
-if(AVX_OPT)
+if(HAVE_AVX)
    list(APPEND arch_files_opt src/arch/dotproductavx.cpp)
-   set_source_files_properties(src/arch/dotproductavx.cpp PROPERTIES COMPILE_FLAGS "-DAVX")
-endif(AVX_OPT)
-if(AVX2_OPT)
+   set_source_files_properties(src/arch/dotproductavx.cpp PROPERTIES COMPILE_FLAGS "-mavx")
+endif(HAVE_AVX)
+if(HAVE_AVX2)
    list(APPEND arch_files_opt src/arch/intsimdmatrixavx2.cpp)
-   set_source_files_properties(src/arch/intsimdmatrixavx2.cpp PROPERTIES COMPILE_FLAGS "-DAVX2")
-endif(AVX2_OPT)
-if(FMA_OPT)
+   set_source_files_properties(src/arch/intsimdmatrixavx2.cpp PROPERTIES COMPILE_FLAGS "-mavx2")
+endif(HAVE_AVX2)
+if(HAVE_FMA)
    list(APPEND arch_files_opt src/arch/dotproductfma.cpp)
    set_source_files_properties(src/arch/dotproductfma.cpp PROPERTIES COMPILE_FLAGS "-mfma")
-endif(FMA_OPT)
-if(SSE41_OPT)
+endif(HAVE_FMA)
+if(HAVE_SSE4_1)
    list(APPEND arch_files_opt src/arch/dotproductsse.cpp src/arch/intsimdmatrixsse.cpp)
-   set_source_files_properties(src/arch/dotproductsse.cpp src/arch/intsimdmatrixsse.cpp PROPERTIES COMPILE_FLAGS "-DSSE4_1 -msse4.1")
-endif(SSE41_OPT)
+   set_source_files_properties(src/arch/dotproductsse.cpp src/arch/intsimdmatrixsse.cpp PROPERTIES COMPILE_FLAGS "-msse4.1")
+endif(HAVE_SSE4_1)
 set_source_files_properties(${arch_files_opt} PROPERTIES COMPILE_FLAGS "${Vc_CXX_FLAGS}")
 
 file(GLOB tesseract_hdr
diff --git a/Makefile.am b/Makefile.am
index 444cf0fe..58146b4b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -150,19 +150,6 @@ libtesseract_la_LIBADD += libtesseract_textord.la
 libtesseract_la_LIBADD += libtesseract_viewer.la
 libtesseract_la_LIBADD += libtesseract_wordrec.la
 
-if AVX_OPT
-libtesseract_la_LIBADD += libtesseract_avx.la
-endif
-if AVX2_OPT
-libtesseract_la_LIBADD += libtesseract_avx2.la
-endif
-if FMA_OPT
-libtesseract_la_LIBADD += libtesseract_fma.la
-endif
-if SSE41_OPT
-libtesseract_la_LIBADD += libtesseract_sse.la
-endif
-
 libtesseract_la_LDFLAGS += -version-info $(GENERIC_LIBRARY_VERSION) $(NOUNDEFINED)
 
 # Rules for src/arch.
@@ -177,37 +164,8 @@ noinst_HEADERS += src/arch/intsimdmatrix.h
 noinst_HEADERS += src/arch/simddetect.h
 
 noinst_LTLIBRARIES += libtesseract_native.la
-if AVX_OPT
-noinst_LTLIBRARIES += libtesseract_avx.la
-endif
-if AVX2_OPT
-noinst_LTLIBRARIES += libtesseract_avx2.la
-endif
-if FMA_OPT
-noinst_LTLIBRARIES += libtesseract_fma.la
-endif
-if SSE41_OPT
-noinst_LTLIBRARIES += libtesseract_sse.la
-endif
 noinst_LTLIBRARIES += libtesseract_arch.la
 
-if AVX_OPT
-libtesseract_arch_la_CPPFLAGS += -DAVX
-libtesseract_avx_la_CXXFLAGS = -mavx
-endif
-if AVX2_OPT
-libtesseract_arch_la_CPPFLAGS += -DAVX2
-libtesseract_avx2_la_CXXFLAGS = -mavx2
-endif
-if FMA_OPT
-libtesseract_arch_la_CPPFLAGS += -DFMA
-libtesseract_fma_la_CXXFLAGS = -mfma
-endif
-if SSE41_OPT
-libtesseract_arch_la_CPPFLAGS += -DSSE4_1
-libtesseract_sse_la_CXXFLAGS = -msse4.1
-endif
-
 libtesseract_native_la_CXXFLAGS = -O3 -ffast-math
 if MARCH_NATIVE_OPT
 libtesseract_native_la_CXXFLAGS += -march=native -mtune=native
@@ -216,20 +174,32 @@ libtesseract_native_la_SOURCES = src/arch/dotproduct.cpp
 
 libtesseract_arch_la_SOURCES = src/arch/intsimdmatrix.cpp src/arch/simddetect.cpp
 
-if AVX_OPT
+if HAVE_AVX
+libtesseract_avx_la_CXXFLAGS = -mavx
 libtesseract_avx_la_SOURCES = src/arch/dotproductavx.cpp
+libtesseract_la_LIBADD += libtesseract_avx.la
+noinst_LTLIBRARIES += libtesseract_avx.la
 endif
 
-if AVX2_OPT
+if HAVE_AVX2
+libtesseract_avx2_la_CXXFLAGS = -mavx2
 libtesseract_avx2_la_SOURCES = src/arch/intsimdmatrixavx2.cpp
+libtesseract_la_LIBADD += libtesseract_avx2.la
+noinst_LTLIBRARIES += libtesseract_avx2.la
 endif
 
-if FMA_OPT
+if HAVE_FMA
+libtesseract_fma_la_CXXFLAGS = -mfma
 libtesseract_fma_la_SOURCES = src/arch/dotproductfma.cpp
+libtesseract_la_LIBADD += libtesseract_fma.la
+noinst_LTLIBRARIES += libtesseract_fma.la
 endif
 
-if SSE41_OPT
+if HAVE_SSE4_1
+libtesseract_sse_la_CXXFLAGS = -msse4.1
 libtesseract_sse_la_SOURCES = src/arch/dotproductsse.cpp src/arch/intsimdmatrixsse.cpp
+libtesseract_la_LIBADD += libtesseract_sse.la
+noinst_LTLIBRARIES += libtesseract_sse.la
 endif
 
 # Rules for src/ccmain.
diff --git a/configure.ac b/configure.ac
index 951c2491..0550e1c1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -125,16 +125,28 @@ AX_CHECK_COMPILE_FLAG([-Werror=unused-command-line-argument], [WERROR=-Werror=un
 ## Checks for supported compiler options.
 
 AX_CHECK_COMPILE_FLAG([-mavx], [avx=true], [avx=false], [$WERROR])
-AM_CONDITIONAL([AVX_OPT], ${avx})
+AM_CONDITIONAL([HAVE_AVX], ${avx})
+if $avx; then
+  AC_DEFINE([HAVE_AVX], [1], [Enable AVX instructions])
+fi
 
 AX_CHECK_COMPILE_FLAG([-mavx2], [avx2=true], [avx2=false], [$WERROR])
-AM_CONDITIONAL([AVX2_OPT], $avx2)
+AM_CONDITIONAL([HAVE_AVX2], $avx2)
+if $avx2; then
+  AC_DEFINE([HAVE_AVX2], [1], [Enable AVX2 instructions])
+fi
 
 AX_CHECK_COMPILE_FLAG([-mfma], [fma=true], [fma=false], [$WERROR])
-AM_CONDITIONAL([FMA_OPT], $fma)
+AM_CONDITIONAL([HAVE_FMA], $fma)
+if $fma; then
+  AC_DEFINE([HAVE_FMA], [1], [Enable FMA instructions])
+fi
 
 AX_CHECK_COMPILE_FLAG([-msse4.1], [sse41=true], [sse41=false], [$WERROR])
-AM_CONDITIONAL([SSE41_OPT], $sse41)
+AM_CONDITIONAL([HAVE_SSE4_1], $sse41)
+if $sse41; then
+  AC_DEFINE([HAVE_SSE4_1], [1], [Enable SSE 4.1 instructions])
+fi
 
 AX_CHECK_COMPILE_FLAG([-march=native], [arch_native=true], [arch_native=false], [$WERROR])
 AM_CONDITIONAL([MARCH_NATIVE_OPT], $arch_native)
diff --git a/src/arch/simddetect.cpp b/src/arch/simddetect.cpp
index b580fa1c..127764e0 100644
--- a/src/arch/simddetect.cpp
+++ b/src/arch/simddetect.cpp
@@ -15,6 +15,7 @@
 // limitations under the License.
 ///////////////////////////////////////////////////////////////////////
 
+#include "config_auto.h"     // for HAVE_AVX, ...
 #include <numeric>           // for std::inner_product
 #include "simddetect.h"
 #include "dotproduct.h"
@@ -22,7 +23,7 @@
 #include "params.h"   // for STRING_VAR
 #include "tprintf.h"  // for tprintf
 
-#if defined(AVX) || defined(AVX2) || defined(FMA) || defined(SSE4_1)
+#if defined(HAVE_AVX) || defined(HAVE_AVX2) || defined(HAVE_FMA) || defined(HAVE_SSE4_1)
 # define HAS_CPUID
 #endif
 
@@ -95,13 +96,13 @@ SIMDDetect::SIMDDetect() {
   if (__get_cpuid(1, &eax, &ebx, &ecx, &edx) != 0) {
     // Note that these tests all use hex because the older compilers don't have
     // the newer flags.
-#if defined(SSE4_1)
+#if defined(HAVE_SSE4_1)
     sse_available_ = (ecx & 0x00080000) != 0;
 #endif
-#if defined(FMA)
+#if defined(HAVE_FMA)
     fma_available_ = (ecx & 0x00001000) != 0;
 #endif
-#if defined(AVX)
+#if defined(HAVE_AVX)
     avx_available_ = (ecx & 0x10000000) != 0;
     if (avx_available_) {
       // There is supposed to be a __get_cpuid_count function, but this is all
@@ -121,19 +122,19 @@ SIMDDetect::SIMDDetect() {
   max_function_id = cpuInfo[0];
   if (max_function_id >= 1) {
     __cpuid(cpuInfo, 1);
-#if defined(SSE4_1)
+#if defined(HAVE_SSE4_1)
     sse_available_ = (cpuInfo[2] & 0x00080000) != 0;
 #endif
-#if defined(AVX) || defined(AVX2) || defined(FMA)
+#if defined(HAVE_AVX) || defined(HAVE_AVX2) || defined(HAVE_FMA)
     if ((cpuInfo[2] & 0x08000000) && ((_xgetbv(0) & 6) == 6)) {
       // OSXSAVE bit is set, XMM state and YMM state are fine.
-#if defined(FMA)
+#if defined(HAVE_FMA)
       fma_available_ = (cpuInfo[2] & 0x00001000) != 0;
 #endif
-#if defined(AVX)
+#if defined(HAVE_AVX)
       avx_available_ = (cpuInfo[2] & 0x10000000) != 0;
 #endif
-#if defined(AVX2)
+#if defined(HAVE_AVX2)
       if (max_function_id >= 7) {
         __cpuid(cpuInfo, 7);
         avx2_available_ = (cpuInfo[1] & 0x00000020) != 0;
@@ -152,17 +153,17 @@ SIMDDetect::SIMDDetect() {
   // Select code for calculation of dot product based on autodetection.
   if (false) {
     // This is a dummy to support conditional compilation.
-#if defined(AVX2)
+#if defined(HAVE_AVX2)
   } else if (avx2_available_) {
     // AVX2 detected.
     SetDotProduct(DotProductAVX, &IntSimdMatrix::intSimdMatrixAVX2);
 #endif
-#if defined(AVX)
+#if defined(HAVE_AVX)
   } else if (avx_available_) {
     // AVX detected.
     SetDotProduct(DotProductAVX, &IntSimdMatrix::intSimdMatrixSSE);
 #endif
-#if defined(SSE4_1)
+#if defined(HAVE_SSE4_1)
   } else if (sse_available_) {
     // SSE detected.
     SetDotProduct(DotProductSSE, &IntSimdMatrix::intSimdMatrixSSE);
@@ -184,25 +185,25 @@ void SIMDDetect::Update() {
     // Native optimized code selected by config variable.
     SetDotProduct(DotProductNative);
     dotproduct_method = "native";
-#if defined(AVX2)
+#if defined(HAVE_AVX2)
   } else if (!strcmp(dotproduct.c_str(), "avx2")) {
     // AVX2 selected by config variable.
     SetDotProduct(DotProductAVX, &IntSimdMatrix::intSimdMatrixAVX2);
     dotproduct_method = "avx2";
 #endif
-#if defined(AVX)
+#if defined(HAVE_AVX)
   } else if (!strcmp(dotproduct.c_str(), "avx")) {
     // AVX selected by config variable.
     SetDotProduct(DotProductAVX, &IntSimdMatrix::intSimdMatrixSSE);
     dotproduct_method = "avx";
 #endif
-#if defined(FMA)
+#if defined(HAVE_FMA)
   } else if (!strcmp(dotproduct.c_str(), "fma")) {
     // FMA selected by config variable.
     SetDotProduct(DotProductFMA, IntSimdMatrix::intSimdMatrix);
     dotproduct_method = "fma";
 #endif
-#if defined(SSE4_1)
+#if defined(HAVE_SSE4_1)
   } else if (!strcmp(dotproduct.c_str(), "sse")) {
     // SSE selected by config variable.
     SetDotProduct(DotProductSSE, &IntSimdMatrix::intSimdMatrixSSE);
@@ -217,10 +218,10 @@ void SIMDDetect::Update() {
     tprintf("Warning, ignoring unsupported config variable value: dotproduct=%s\n",
             dotproduct.c_str());
     tprintf("Support values for dotproduct: auto generic native"
-#if defined(AVX)
+#if defined(HAVE_AVX)
             " avx"
 #endif
-#if defined(SSE4_1)
+#if defined(HAVE_SSE4_1)
             " sse"
 #endif
             " std::inner_product.\n");
diff --git a/unittest/Makefile.am b/unittest/Makefile.am
index 0623848b..3037f649 100644
--- a/unittest/Makefile.am
+++ b/unittest/Makefile.am
@@ -271,11 +271,11 @@ intfeaturemap_test_LDADD = $(TRAINING_LIBS)
 intsimdmatrix_test_SOURCES = intsimdmatrix_test.cc
 intsimdmatrix_test_LDADD = $(TESS_LIBS)
 intsimdmatrix_test_CPPFLAGS = $(AM_CPPFLAGS)
-if AVX2_OPT
-intsimdmatrix_test_CPPFLAGS += -DAVX2
+if HAVE_AVX2
+intsimdmatrix_test_CPPFLAGS += -DHAVE_AVX2
 endif
-if SSE41_OPT
-intsimdmatrix_test_CPPFLAGS += -DSSE4_1
+if HAVE_SSE4_1
+intsimdmatrix_test_CPPFLAGS += -DHAVE_SSE4_1
 endif
 
 lang_model_test_SOURCES = lang_model_test.cc
diff --git a/unittest/intsimdmatrix_test.cc b/unittest/intsimdmatrix_test.cc
index 09326246..8ddd8998 100644
--- a/unittest/intsimdmatrix_test.cc
+++ b/unittest/intsimdmatrix_test.cc
@@ -98,7 +98,7 @@ TEST_F(IntSimdMatrixTest, C) {
 
 // Tests that the SSE implementation gets the same result as the vanilla.
 TEST_F(IntSimdMatrixTest, SSE) {
-#if defined(SSE4_1)
+#if defined(HAVE_SSE4_1)
   if (SIMDDetect::IsSSEAvailable()) {
     tprintf("SSE found! Continuing...");
   } else {
@@ -113,7 +113,7 @@ TEST_F(IntSimdMatrixTest, SSE) {
 
 // Tests that the AVX2 implementation gets the same result as the vanilla.
 TEST_F(IntSimdMatrixTest, AVX2) {
-#if defined(AVX2)
+#if defined(HAVE_AVX2)
   if (SIMDDetect::IsAVX2Available()) {
     tprintf("AVX2 found! Continuing...");
   } else {