Add ARMv6 fallback to jit (it doesn't have MOVW/MOVT)

Common/ArmABI.cpp

@@ -76,30 +76,6 @@ void ARMXEmitter::ARMABI_PopAllCalleeSavedRegsAndAdjustStack() {
 	POP(4, R0, R1, R2, R3);
 }
 
-void ARMXEmitter::ARMABI_MOVI2R(ARMReg reg, u32 val)
-{
-	Operand2 op2;
-	bool inverse;
-	if (TryMakeOperand2_AllowInverse(val, op2, &inverse)) {
-		if (!inverse)
-			MOV(reg, op2);
-		else
-			MVN(reg, op2);
-	} else {
-		MOVW(reg, val);
-		if(val & 0xFFFF0000) 
-			MOVT(reg, val, true);
-	}
-}
-// Moves IMM to memory location
-void ARMXEmitter::ARMABI_MOVI2M(Operand2 op, Operand2 val)
-{
-	// This moves imm to a memory location
-	MOVW(R14, val); MOVT(R14, val, true);
-	MOVW(R12, op); MOVT(R12, op, true);
-	STR(R12, R14); // R10 is what we want to store
-}
-
 const char *conditions[] = {"EQ", "NEQ", "CS", "CC", "MI", "PL", "VS", "VC", "HI", "LS", "GE", "LT", "GT", "LE", "AL" };      
 static void ShowCondition(u32 cond)
 {

Common/ArmCPUDetect.cpp

@@ -41,6 +41,7 @@ char *GetCPUString()
 			continue;
 		cpu_string = buf + sizeof(marker) - 1;
 		cpu_string = strndup(cpu_string, strlen(cpu_string) - 1); // Strip the newline
+		// INFO_LOG(BOOT, "CPU: %s", cpu_string);
 		break;
 	}
 	return cpu_string;
@@ -150,6 +151,13 @@ void CPUInfo::Detect()
 	bFP = false;
 	bASIMD = false;
 #endif
+// On android, we build a separate library for ARMv7 so this is fine.
+// TODO: Check for ARMv7 on other platforms.
+#if defined(__ARM_ARCH_7A__)
+	bArmV7 = true;
+#else
+	bArmV7 = false;
+#endif
 }
 
 // Turn the cpu info into a string we can show

Common/ArmEmitter.cpp

@@ -78,6 +78,44 @@ bool TryMakeOperand2_AllowNegation(s32 imm, Operand2 &op2, bool *negated)
 	}
 }
 
+void ARMXEmitter::ARMABI_MOVI2R(ARMReg reg, u32 val)
+{
+	Operand2 op2;
+	bool inverse;
+	if (TryMakeOperand2_AllowInverse(val, op2, &inverse)) {
+		if (!inverse)
+			MOV(reg, op2);
+		else
+			MVN(reg, op2);
+	} else {
+		if (cpu_info.bArmV7) {
+			// ARMv7 - can use MOVT/MOVW, best choice
+			MOVW(reg, val & 0xFFFF);
+			if(val & 0xFFFF0000)
+				MOVT(reg, val, true);
+		} else {
+			// ARMv6 - fallback sequence.
+			// TODO: Optimize further. Can for example choose negation etc.
+			// Literal pools is another way to do this but much more complicated
+			// so I can't really be bothered for an outdated CPU architecture like ARMv6.
+			bool first = true;
+			int shift = 16;
+			for (int i = 0; i < 4; i++) {
+				if (val & 0xFF) {
+					if (first) {
+						MOV(reg, Operand2((u8)val, (u8)(shift & 0xF)));
+						first = false;
+					} else {
+						ORR(reg, reg, Operand2((u8)val, (u8)(shift & 0xF)));
+					}
+				}
+				shift -= 4;
+				val >>= 8;
+			}
+		}
+	}
+}
+
 void ARMXEmitter::QuickCallFunction(ARMReg reg, void *func) {
 	ARMABI_MOVI2R(reg, (u32)(func));
 	BL(reg);

Common/ArmEmitter.h

@@ -481,8 +481,6 @@ public:
 	void ARMABI_PushAllCalleeSavedRegsAndAdjustStack(); 
 	void ARMABI_PopAllCalleeSavedRegsAndAdjustStack(); 
 	void ARMABI_MOVI2R(ARMReg reg, u32 val);
-	void ARMABI_MOVI2M(Operand2 op, Operand2 val);
-	void ARMABI_MOVI2M(u32 addr, Operand2 val);
 	void ARMABI_ShowConditions();
 	void ARMABI_Return();
 

Common/CPUDetect.h

@@ -71,6 +71,8 @@ struct CPUInfo
 	bool bVFPv4;
 	bool bIDIVa;
 	bool bIDIVt;
+	bool bArmV7;  // enable MOVT, MOVW etc
+
 	// ARMv8 specific
 	bool bFP;
 	bool bASIMD;