Support ARM compilation with Subzero.

CMakeLists.txt

@@ -49,10 +49,18 @@ else()
     message(FATAL_ERROR "Platform is not supported")
 endif()
 
-if(CMAKE_SIZEOF_VOID_P EQUAL 8)
-    set(ARCH "x86_64")
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "arm" OR CMAKE_SYSTEM_PROCESSOR MATCHES "aarch")
+    if(CMAKE_SIZEOF_VOID_P EQUAL 8)
+        set(ARCH "aarch64")
+    else()
+        set(ARCH "arm")
+    endif()
 else()
+    if(CMAKE_SIZEOF_VOID_P EQUAL 8)
+        set(ARCH "x86_64")
+    else()
         set(ARCH "x86")
+    endif()
 endif()
 
 ###########################################################
@@ -591,25 +599,35 @@ if(${REACTOR_BACKEND} STREQUAL "Subzero")
         ${SUBZERO_DIR}/src/IceRNG.cpp
         ${SUBZERO_DIR}/src/IceSwitchLowering.cpp
         ${SUBZERO_DIR}/src/IceTargetLowering.cpp
-        ${SUBZERO_DIR}/src/IceTargetLoweringX86.cpp
         ${SUBZERO_DIR}/src/IceThreading.cpp
         ${SUBZERO_DIR}/src/IceTimerTree.cpp
         ${SUBZERO_DIR}/src/IceTypes.cpp
         ${SUBZERO_DIR}/src/IceVariableSplitting.cpp
     )
 
-    if(CMAKE_SIZEOF_VOID_P EQUAL 8)
+    if(ARCH STREQUAL "x86_64")
         list(APPEND SUBZERO_LIST
+            ${SUBZERO_DIR}/src/IceTargetLoweringX86.cpp
             ${SUBZERO_DIR}/src/IceInstX8664.cpp
             ${SUBZERO_DIR}/src/IceTargetLoweringX8664.cpp
         )
         set(SUBZERO_TARGET X8664)
-    else()
+    elseif(ARCH STREQUAL "x86")
         list(APPEND SUBZERO_LIST
+            ${SUBZERO_DIR}/src/IceTargetLoweringX86.cpp
             ${SUBZERO_DIR}/src/IceInstX8632.cpp
             ${SUBZERO_DIR}/src/IceTargetLoweringX8632.cpp
         )
         set(SUBZERO_TARGET X8632)
+    elseif(ARCH STREQUAL "arm")
+        list(APPEND SUBZERO_LIST
+            ${SUBZERO_DIR}/src/IceAssemblerARM32.cpp
+            ${SUBZERO_DIR}/src/IceInstARM32.cpp
+            ${SUBZERO_DIR}/src/IceTargetLoweringARM32.cpp
+        )
+        set(SUBZERO_TARGET ARM32)
+    else()
+        message(FATAL_ERROR "Architecture '${ARCH}' not supported by Subzero")
     endif()
 
     file(GLOB_RECURSE SUBZERO_DEPENDENCIES_LIST

src/Reactor/SubzeroReactor.cpp

@@ -230,6 +230,7 @@ namespace sw
 			}
 		}
 
+		#if defined(__i386__)
 			switch(relocation.getType())
 			{
 			case R_386_NONE:
@@ -245,6 +246,30 @@ namespace sw
 				assert(false && "Unsupported relocation type");
 				return nullptr;
 			}
+		#elif defined(__arm__)
+			switch(relocation.getType())
+			{
+			case R_ARM_NONE:
+				// No relocation
+				break;
+			case R_ARM_MOVW_ABS_NC:
+				{
+					uint32_t thumb = 0;   // Calls to Thumb code not supported.
+					uint32_t lo = (uint32_t)symbolValue | thumb;
+					*patchSite = (*patchSite & 0xFFF0F000) | ((lo & 0xF000) << 4) | (lo & 0x0FFF);
+				}
+				break;
+			case R_ARM_MOVT_ABS:
+				{
+					uint32_t hi = (uint32_t)(symbolValue) >> 16;
+					*patchSite = (*patchSite & 0xFFF0F000) | ((hi & 0xF000) << 4) | (hi & 0x0FFF);
+				}
+				break;
+			default:
+				assert(false && "Unsupported relocation type");
+				return nullptr;
+			}
+		#endif
 
 		return symbolValue;
 	}
@@ -286,6 +311,7 @@ namespace sw
 			}
 		}
 
+		#if defined(__x86_64__)
 			switch(relocation.getType())
 			{
 			case R_X86_64_NONE:
@@ -304,6 +330,7 @@ namespace sw
 				assert(false && "Unsupported relocation type");
 				return nullptr;
 			}
+		#endif
 
 		return symbolValue;
 	}
@@ -319,7 +346,15 @@ namespace sw
 
 		// Expect ELF bitness to match platform
 		assert(sizeof(void*) == 8 ? elfHeader->getFileClass() == ELFCLASS64 : elfHeader->getFileClass() == ELFCLASS32);
-		assert(sizeof(void*) == 8 ? elfHeader->e_machine == EM_X86_64 : elfHeader->e_machine == EM_386);
+		#if defined(__i386__)
+			assert(sizeof(void*) == 4 && elfHeader->e_machine == EM_386);
+		#elif defined(__x86_64__)
+			assert(sizeof(void*) == 8 && elfHeader->e_machine == EM_X86_64);
+		#elif defined(__arm__)
+			assert(sizeof(void*) == 4 && elfHeader->e_machine == EM_ARM);
+		#else
+			#error "Unsupported platform"
+		#endif
 
 		SectionHeader *sectionHeader = (SectionHeader*)(elfImage + elfHeader->e_shoff);
 		void *entry = nullptr;
@@ -479,12 +514,18 @@ namespace sw
 		Ice::ClFlags &Flags = Ice::ClFlags::Flags;
 		Ice::ClFlags::getParsedClFlags(Flags);
 
+		#if defined(__arm__)
+			Flags.setTargetArch(Ice::Target_ARM32);
+			Flags.setTargetInstructionSet(Ice::ARM32InstructionSet_HWDivArm);
+		#else   // x86
 			Flags.setTargetArch(sizeof(void*) == 8 ? Ice::Target_X8664 : Ice::Target_X8632);
+			Flags.setTargetInstructionSet(CPUID::SSE4_1 ? Ice::X86InstructionSet_SSE4_1 : Ice::X86InstructionSet_SSE2);
+		#endif
 		Flags.setOutFileType(Ice::FT_Elf);
 		Flags.setOptLevel(Ice::Opt_2);
 		Flags.setApplicationBinaryInterface(Ice::ABI_Platform);
-		Flags.setTargetInstructionSet(CPUID::SSE4_1 ? Ice::X86InstructionSet_SSE4_1 : Ice::X86InstructionSet_SSE2);
-		Flags.setVerbose(false ? Ice::IceV_All : Ice::IceV_None);
+		Flags.setVerbose(false ? Ice::IceV_Most : Ice::IceV_None);
+		Flags.setDisableHybridAssembly(true);
 
 		static llvm::raw_os_ostream cout(std::cout);
 		static llvm::raw_os_ostream cerr(std::cerr);