diff --git a/regamedll/build.gradle b/regamedll/build.gradle
index 4e46ebce..3486ce33 100644
--- a/regamedll/build.gradle
+++ b/regamedll/build.gradle
@@ -24,6 +24,7 @@ import org.apache.commons.compress.archivers.ArchiveInputStream
 
 apply plugin: 'cpp'
 apply plugin: IccCompilerPlugin
+apply plugin: GccCompilerPlugin
 apply plugin: RegamedllPlayTestPlugin
 apply plugin: gradlecpp.CppUnitTestPlugin
 
@@ -59,11 +60,11 @@ void createIntergrationTestTask(NativeBinarySpec b) {
 		testDemos = project.configurations.regamedll_tests
 		testFor = b
 
-		//inputs/outputs for up-to-date check
+		// inputs/outputs for up-to-date check
 		inputs.files testDemos.files
 		outputs.dir regamedllTestLogs
 
-		//dependencies on test executable
+		// dependencies on test executable
 		if (unitTestTask) {
 			dependsOn unitTestTask
 		}
@@ -90,6 +91,7 @@ void postEvaluate(NativeBinarySpec b) {
 
 void setupToolchain(NativeBinarySpec b)
 {
+	boolean useGcc = project.hasProperty("useGcc")
 	boolean unitTestExecutable = b.component.name.endsWith('_tests')
 	boolean regamedllFixes = b.flavor.name.contains('regamedllFixes')
 
@@ -127,10 +129,13 @@ void setupToolchain(NativeBinarySpec b)
 	}
 	else if (cfg instanceof GccToolchainConfig)
 	{
-		cfg.compilerOptions.pchConfig = new GccToolchainConfig.PrecompilerHeaderOptions(
-			enabled: true,
-			pchSourceSet: 'regamedll_pch'
-		);
+		if (!useGcc)
+		{
+			cfg.compilerOptions.pchConfig = new GccToolchainConfig.PrecompilerHeaderOptions(
+				enabled: true,
+				pchSourceSet: 'regamedll_pch'
+			);
+		}
 
 		cfg.compilerOptions.languageStandard = 'c++14'
 		cfg.defines([
@@ -145,8 +150,22 @@ void setupToolchain(NativeBinarySpec b)
 			'_access' : 'access'
 		])
 
-		cfg.linkerOptions.args '-no-opt-class-analysis'
-		cfg.compilerOptions.args '-Qoption,cpp,--treat_func_as_string_literal_cpp', '-g0', '-fno-rtti', '-fno-exceptions'
+		if (useGcc) {
+			// Produce code optimized for the most common IA32/AMD64/EM64T processors.
+			// As new processors are deployed in the marketplace, the behavior of this option will change.
+			cfg.compilerOptions.args '-mtune=generic', '-msse3', '-Wno-write-strings', '-Wno-invalid-offsetof', '-fpermissive', '-fno-devirtualize'
+		} else {
+			cfg.compilerOptions.args '-Qoption,cpp,--treat_func_as_string_literal_cpp'
+
+			// Not use c++ class hierarchy for analyze and resolve C++ virtual function calls at compile time.
+			//
+			// Example issue:
+			// Expected: FF .. call dword ptr + offset, pEntity->Spawn();
+			// Got:      E8 .. call CBaseEntity::Spawn();
+			cfg.linkerOptions.args '-qno-opt-class-analysis'
+		}
+
+		cfg.compilerOptions.args '-g0', '-fno-rtti', '-fno-exceptions'
 		cfg.projectLibpath(project, '/lib/linux32')
 		cfg.extraLibs 'dl', 'm', 'stdc++', 'aelf32'
 	}
@@ -243,7 +262,10 @@ model {
 	toolChains {
 		visualCpp(VisualCpp) {
 		}
-		icc(Icc) {
+		if (project.hasProperty("useGcc")) {
+			gcc(Gcc)
+		} else {
+			icc(Icc)
 		}
 	}
 
diff --git a/regamedll/common/mathlib.h b/regamedll/common/mathlib.h
index 52723986..410d1de9 100644
--- a/regamedll/common/mathlib.h
+++ b/regamedll/common/mathlib.h
@@ -29,7 +29,7 @@
 #pragma once
 
 #ifdef PLAY_GAMEDLL
-// NOTE: In some cases we need high precision of floating-point,
+// NOTE: In some cases we need high precision of floating-point,
 // so use double instead of float, otherwise unittest will fail
 typedef double real_t;
 #else
@@ -85,6 +85,7 @@ const T& clamp(const T& a, const T& min, const T& max) { return (a > max) ? max
 #define clamp(val, min, max) (((val) > (max)) ? (max) : (((val) < (min)) ? (min) : (val)))
 #endif // __cplusplus
 
+#ifdef HAVE_SSE
 inline float M_sqrt(float value) {
 	return _mm_cvtss_f32(_mm_sqrt_ss(_mm_load_ss(&value)));
 }
@@ -93,12 +94,14 @@ inline double M_sqrt(double value) {
 	auto v = _mm_load_sd(&value);
 	return _mm_cvtsd_f64(_mm_sqrt_sd(v, v));
 }
+#endif
 
 template<typename T>
 inline double M_sqrt(T value) {
 	return sqrt(value);
 }
 
+#ifdef HAVE_SSE
 inline float M_min(float a, float b) {
 	return _mm_cvtss_f32(_mm_min_ss(_mm_load_ss(&a), _mm_load_ss(&b)));
 }
@@ -106,12 +109,14 @@ inline float M_min(float a, float b) {
 inline double M_min(double a, double b) {
 	return _mm_cvtsd_f64(_mm_min_sd(_mm_load_sd(&a), _mm_load_sd(&b)));
 }
+#endif
 
 template<typename T>
 inline T M_min(T a, T b) {
 	return min(a, b);
 }
 
+#ifdef HAVE_SSE
 inline float M_max(float a, float b) {
 	return _mm_cvtss_f32(_mm_max_ss(_mm_load_ss(&a), _mm_load_ss(&b)));
 }
@@ -119,12 +124,14 @@ inline float M_max(float a, float b) {
 inline double M_max(double a, double b) {
 	return _mm_cvtsd_f64(_mm_max_sd(_mm_load_sd(&a), _mm_load_sd(&b)));
 }
+#endif
 
 template<typename T>
 inline T M_max(T a, T b) {
 	return max(a, b);
 }
 
+#ifdef HAVE_SSE
 inline float M_clamp(float a, float min, float max) {
 	return _mm_cvtss_f32(_mm_min_ss(_mm_max_ss(_mm_load_ss(&a), _mm_load_ss(&min)), _mm_load_ss(&max)));
 }
@@ -132,6 +139,7 @@ inline float M_clamp(float a, float min, float max) {
 inline double M_clamp(double a, double min, double max) {
 	return _mm_cvtsd_f64(_mm_min_sd(_mm_max_sd(_mm_load_sd(&a), _mm_load_sd(&min)), _mm_load_sd(&max)));
 }
+#endif
 
 template<typename T>
 inline T M_clamp(T a, T min, T max) {
diff --git a/regamedll/dlls/animation.cpp b/regamedll/dlls/animation.cpp
index 78b3ff67..e8f0ab0f 100644
--- a/regamedll/dlls/animation.cpp
+++ b/regamedll/dlls/animation.cpp
@@ -527,7 +527,7 @@ C_DLLEXPORT int Server_GetBlendingInterface(int version, struct sv_blending_inte
 	return 1;
 }
 
-#ifdef REGAMEDLL_FIXES // SSE2 version
+#if defined(REGAMEDLL_FIXES) && defined(HAVE_SSE) // SSE2 version
 void AngleQuaternion(vec_t *angles, vec_t *quaternion)
 {
 	static const ALIGN16_BEG size_t ps_signmask[4] ALIGN16_END = { 0x80000000, 0, 0x80000000, 0 };
diff --git a/regamedll/dlls/player.cpp b/regamedll/dlls/player.cpp
index e4325422..e54521a7 100644
--- a/regamedll/dlls/player.cpp
+++ b/regamedll/dlls/player.cpp
@@ -8296,6 +8296,9 @@ void CBasePlayer::ClientCommand(const char *cmd, const char *arg1, const char *a
 
 	auto pEntity = ENT(pev);
 
+#ifdef NO_AMXX_HACKS // a1ba: not needed for non-x86 port
+	::ClientCommand_(pEntity);
+#else // NO_AMXX_HACKS
 	// NOTE: force __cdecl to allow cstrike amxx module to hook ClientCommand
 #if defined _MSC_VER || defined __INTEL_COMPILER
 	__asm
@@ -8307,13 +8310,13 @@ void CBasePlayer::ClientCommand(const char *cmd, const char *arg1, const char *a
 #else
 	asm volatile (
 		"pushl %0\n\t"
-		"call %1\n\t"
-		"addl %%esp, $4\n\t"
-		::
-		"g" (pEntity),
-		"g" (ClientCommand_),
+		"call *%1\n\t"
+		"addl $4, %%esp\n\t"
+		: /* no outputs */
+		: "g" (pEntity), "g" (ClientCommand_)
 	);
 #endif // _MSC_VER || defined __INTEL_COMPILER
+#endif // NO_AMXX_HACKS
 
 	UseBotArgs = false;
 }
diff --git a/regamedll/dlls/saverestore.cpp b/regamedll/dlls/saverestore.cpp
index 3a03b562..0522ce8f 100644
--- a/regamedll/dlls/saverestore.cpp
+++ b/regamedll/dlls/saverestore.cpp
@@ -160,6 +160,28 @@ void EntvarsKeyvalue(entvars_t *pev, KeyValueData *pkvd)
 	}
 }
 
+const int CSaveRestoreBuffer::m_Sizes[] =
+{
+	sizeof(float),     // FIELD_FLOAT
+	sizeof(int),       // FIELD_STRING
+	sizeof(int),       // FIELD_ENTITY
+	sizeof(int),       // FIELD_CLASSPTR
+	sizeof(int),       // FIELD_EHANDLE
+	sizeof(int),       // FIELD_entvars_t
+	sizeof(int),       // FIELD_EDICT
+	sizeof(float) * 3, // FIELD_VECTOR
+	sizeof(float) * 3, // FIELD_POSITION_VECTOR
+	sizeof(int *),     // FIELD_POINTER
+	sizeof(int),       // FIELD_INTEGER
+	sizeof(int *),     // FIELD_FUNCTION
+	sizeof(int),       // FIELD_BOOLEAN
+	sizeof(short),     // FIELD_SHORT
+	sizeof(char),      // FIELD_CHARACTER
+	sizeof(float),     // FIELD_TIME
+	sizeof(int),       // FIELD_MODELNAME
+	sizeof(int),       // FIELD_SOUNDNAME
+};
+
 CSaveRestoreBuffer::CSaveRestoreBuffer()
 {
 	m_pData = nullptr;
diff --git a/regamedll/dlls/saverestore.h b/regamedll/dlls/saverestore.h
index be5d429c..8da3fdb5 100644
--- a/regamedll/dlls/saverestore.h
+++ b/regamedll/dlls/saverestore.h
@@ -85,26 +85,7 @@ public:
 	unsigned short TokenHash(const char *pszToken);
 
 protected:
-	static constexpr int m_Sizes[] = {
-		sizeof(float),     // FIELD_FLOAT
-		sizeof(int),       // FIELD_STRING
-		sizeof(int),       // FIELD_ENTITY
-		sizeof(int),       // FIELD_CLASSPTR
-		sizeof(int),       // FIELD_EHANDLE
-		sizeof(int),       // FIELD_entvars_t
-		sizeof(int),       // FIELD_EDICT
-		sizeof(float) * 3, // FIELD_VECTOR
-		sizeof(float) * 3, // FIELD_POSITION_VECTOR
-		sizeof(int *),     // FIELD_POINTER
-		sizeof(int),       // FIELD_INTEGER
-		sizeof(int *),     // FIELD_FUNCTION
-		sizeof(int),       // FIELD_BOOLEAN
-		sizeof(short),     // FIELD_SHORT
-		sizeof(char),      // FIELD_CHARACTER
-		sizeof(float),     // FIELD_TIME
-		sizeof(int),       // FIELD_MODELNAME
-		sizeof(int),       // FIELD_SOUNDNAME
-	};
+	static const int m_Sizes[];
 
 	SAVERESTOREDATA *m_pData;
 	void BufferRewind(int size);
diff --git a/regamedll/dlls/util.h b/regamedll/dlls/util.h
index 3066eecc..90465823 100644
--- a/regamedll/dlls/util.h
+++ b/regamedll/dlls/util.h
@@ -323,7 +323,8 @@ inline T *UTIL_FindEntityInSphere(T *pStartEntity, const Vector &vecCenter, floa
 	pentEntity = FIND_ENTITY_IN_SPHERE(pentEntity, vecCenter, flRadius);
 	if (!FNullEnt(pentEntity))
 	{
-		return (T *)CBaseEntity::Instance(pentEntity);
+		// a1ba: can't use CBaseEntity::Instance here, because circular dependency in cbase.h
+		return GET_PRIVATE<T>(pentEntity);
 	}
 
 	return nullptr;
diff --git a/regamedll/engine/osconfig.h b/regamedll/engine/osconfig.h
index f9bc5835..1077e7d1 100644
--- a/regamedll/engine/osconfig.h
+++ b/regamedll/engine/osconfig.h
@@ -47,6 +47,12 @@
 #include <deque>
 #include <functional>
 
+// enable SSE code only if it's enabled in compiler options
+#if defined(__SSE__) || defined(__SSE2__) || defined(_M_IX86_FP) || defined(_M_AMD64) || defined(_M_X64)
+	// #error "SSE enabled"
+	#define HAVE_SSE
+#endif
+
 #ifdef _WIN32 // WINDOWS
 	#define WIN32_LEAN_AND_MEAN // Exclude rarely-used stuff from Windows headers
 	#include <windows.h>
@@ -87,9 +93,10 @@
 #include <fstream>
 #include <iomanip>
 
+#ifdef HAVE_SSE
 #include <smmintrin.h>
 #include <xmmintrin.h>
-
+#endif // HAVE_SSE
 
 #ifdef _WIN32 // WINDOWS
 	// Define __func__ on VS less than 2015
@@ -97,6 +104,8 @@
 		#define __func__ __FUNCTION__
 	#endif
 
+	// We'll not use __func__ on windows because we want 'A::foo' instead of 'foo'
+	#define __FUNC__ __FUNCTION__
 	#define _CRT_SECURE_NO_WARNINGS
 	#define WIN32_LEAN_AND_MEAN
 
@@ -151,6 +160,7 @@
 	typedef unsigned int UNINT32;
 
 	#define FASTCALL
+	#define __FUNC__ __func__
 	#define CDECL __attribute__ ((cdecl))
 	#define STDCALL __attribute__ ((stdcall))
 	#define HIDDEN __attribute__((visibility("hidden")))
diff --git a/regamedll/regamedll/hookchains_impl.cpp b/regamedll/regamedll/hookchains_impl.cpp
index 2ba024ce..f9a98228 100644
--- a/regamedll/regamedll/hookchains_impl.cpp
+++ b/regamedll/regamedll/hookchains_impl.cpp
@@ -49,11 +49,11 @@ bool AbstractHookChainRegistry::findHook(void* hookFunc) const
 void AbstractHookChainRegistry::addHook(void* hookFunc, int priority)
 {
 	if (!hookFunc) {
-		Sys_Error("%s: Parameter hookFunc can't be a nullptr", __func__);
+		Sys_Error("%s: Parameter hookFunc can't be a nullptr", __FUNC__);
 	}
 
 	if (findHook(hookFunc)) {
-		Sys_Error("%s: The same handler can't be used twice on the hookchain.", __func__);
+		Sys_Error("%s: The same handler can't be used twice on the hookchain.", __FUNC__);
 	}
 
 	for (auto i = 0; i < MAX_HOOKS_IN_CHAIN; i++)
@@ -72,7 +72,7 @@ void AbstractHookChainRegistry::addHook(void* hookFunc, int priority)
 	}
 
 	if (m_NumHooks >= MAX_HOOKS_IN_CHAIN) {
-		Sys_Error("%s: MAX_HOOKS_IN_CHAIN limit hit", __func__);
+		Sys_Error("%s: MAX_HOOKS_IN_CHAIN limit hit", __FUNC__);
 	}
 
 	m_NumHooks++;
diff --git a/regamedll/regamedll/hookchains_impl.h b/regamedll/regamedll/hookchains_impl.h
index 96452b4a..f3a4a7af 100644
--- a/regamedll/regamedll/hookchains_impl.h
+++ b/regamedll/regamedll/hookchains_impl.h
@@ -54,7 +54,7 @@ public:
 	IHookChainImpl(void** hooks, origfunc_t orig) : m_Hooks(hooks), m_OriginalFunc(orig)
 	{
 		if (orig == nullptr && !is_void(orig))
-			Sys_Error("%s: Non-void HookChain without original function.", __func__);
+			Sys_Error("%s: Non-void HookChain without original function.", __FUNC__);
 	}
 
 	virtual ~IHookChainImpl() {}
@@ -90,7 +90,7 @@ public:
 	IHookChainClassImpl(void** hooks, origfunc_t orig) : m_Hooks(hooks), m_OriginalFunc(orig)
 	{
 		if (orig == nullptr && !is_void(orig))
-			Sys_Error("%s: Non-void HookChain without original function.", __func__);
+			Sys_Error("%s: Non-void HookChain without original function.", __FUNC__);
 	}
 
 	virtual ~IHookChainClassImpl() {}
@@ -126,7 +126,7 @@ public:
 	IHookChainClassEmptyImpl(void** hooks, origfunc_t orig, t_class *object) : m_Hooks(hooks), m_OriginalFunc(orig), m_Object(object)
 	{
 		if (orig == nullptr && !is_void(orig))
-			Sys_Error("%s: Non-void HookChain without original function.", __func__);
+			Sys_Error("%s: Non-void HookChain without original function.", __FUNC__);
 	}
 
 	virtual ~IHookChainClassEmptyImpl() {}
diff --git a/regamedll/regamedll/precompiled.h b/regamedll/regamedll/precompiled.h
index f3799aea..2b9aa3df 100644
--- a/regamedll/regamedll/precompiled.h
+++ b/regamedll/regamedll/precompiled.h
@@ -34,7 +34,9 @@
 #include "basetypes.h"
 
 #include "archtypes.h"
+#ifdef HAVE_SSE
 #include "sse_mathfun.h"
+#endif
 #include "asmlib.h"
 
 #include "MemPool.h"
diff --git a/regamedll/regamedll/sse_mathfun.cpp b/regamedll/regamedll/sse_mathfun.cpp
index 3e59aa8f..52f9b5ac 100644
--- a/regamedll/regamedll/sse_mathfun.cpp
+++ b/regamedll/regamedll/sse_mathfun.cpp
@@ -31,6 +31,8 @@ misrepresented as being the original software.
 
 #include "precompiled.h"
 
+#ifdef HAVE_SSE
+
 /* natural logarithm computed for 4 simultaneous float
 return NaN for x <= 0
 */
@@ -445,3 +447,4 @@ void sincos_ps(v4sf x, v4sf *s, v4sf *c) {
 	*s = _mm_xor_ps(xmm1, sign_bit_sin);
 	*c = _mm_xor_ps(xmm2, sign_bit_cos);
 }
+#endif // HAVE_SSE
diff --git a/shared.gradle b/shared.gradle
index e9690f20..c25cc848 100644
--- a/shared.gradle
+++ b/shared.gradle
@@ -8,6 +8,7 @@ import org.gradle.nativeplatform.toolchain.VisualCpp
 
 apply from: 'shared_msvc.gradle'
 apply from: 'shared_icc.gradle'
+apply from: 'shared_gcc.gradle'
 
 rootProject.ext.createToolchainConfig = { NativeBinarySpec bin ->
 	BinaryKind binaryKind
@@ -37,6 +38,10 @@ rootProject.ext.createToolchainConfig = { NativeBinarySpec bin ->
 	{
 		return rootProject.createIccConfig(releaseBuild, binaryKind)
 	}
+	else if (bin.toolChain instanceof Gcc)
+	{
+		return rootProject.createGccConfig(releaseBuild, binaryKind)
+	}
 	else
 	{
 		throw new RuntimeException("Unknown native toolchain: ${bin.toolChain.class.name}")
diff --git a/shared_gcc.gradle b/shared_gcc.gradle
new file mode 100644
index 00000000..03654bc8
--- /dev/null
+++ b/shared_gcc.gradle
@@ -0,0 +1,55 @@
+import org.doomedsociety.gradlecpp.cfg.BinaryKind
+import org.doomedsociety.gradlecpp.gcc.GccToolchainConfig
+import org.doomedsociety.gradlecpp.gcc.OptimizationLevel
+
+rootProject.ext.createGccConfig = { boolean release, BinaryKind binKind ->
+	GccToolchainConfig cfg
+	if (release) {
+		cfg = new GccToolchainConfig(
+				compilerOptions: new GccToolchainConfig.CompilerOptions(
+						optimizationLevel: OptimizationLevel.LEVEL_3,
+						stackProtector: false,
+						noBuiltIn: true,
+						positionIndependentCode: false,
+						extraDefines: [
+							'_GLIBCXX_USE_CXX11_ABI': 0,
+						]
+				),
+
+				linkerOptions: new GccToolchainConfig.LinkerOptions(
+						stripSymbolTable: false,
+						staticLibGcc: false,
+						staticLibStdCpp: false,
+				),
+
+				librarianOptions: new GccToolchainConfig.LibrarianOptions(
+
+				)
+		)
+	} else {
+		//debug
+		cfg = new GccToolchainConfig(
+				compilerOptions: new GccToolchainConfig.CompilerOptions(
+						optimizationLevel: OptimizationLevel.DISABLE,
+						stackProtector: true,
+						noBuiltIn: true,
+						extraDefines: [
+							'_GLIBCXX_USE_CXX11_ABI': 0,
+						]
+				),
+
+				linkerOptions: new GccToolchainConfig.LinkerOptions(
+						stripSymbolTable: false,
+						staticLibGcc: false,
+						staticLibStdCpp: false,
+				),
+
+				librarianOptions: new GccToolchainConfig.LibrarianOptions(
+
+				)
+		)
+	}
+
+	cfg.singleDefines('LINUX', '_LINUX')
+	return cfg
+}
diff --git a/shared_icc.gradle b/shared_icc.gradle
index afa5aaec..424750f9 100644
--- a/shared_icc.gradle
+++ b/shared_icc.gradle
@@ -60,5 +60,6 @@ rootProject.ext.createIccConfig = { boolean release, BinaryKind binKind ->
 		)
 	}
 
+	cfg.singleDefines('LINUX', '_LINUX')
 	return cfg
 }