diff --git a/compiler_and_linker/unsorted/InterferenceGraph.c b/compiler_and_linker/unsorted/InterferenceGraph.c
index cc78a63..99f4512 100644
--- a/compiler_and_linker/unsorted/InterferenceGraph.c
+++ b/compiler_and_linker/unsorted/InterferenceGraph.c
@@ -38,7 +38,7 @@ static void buildinterferencematrix(void) {
     PCode *instr; // r29
     UInt32 *vec; // r28
     PCodeArg *op;
-    long reg;
+    int reg;
     UInt32 i;
     UInt32 j;
 
@@ -76,7 +76,7 @@ static void buildinterferencematrix(void) {
             for (op = instr->args, i = instr->argCount; i--; op++) {
                 if (PC_OP_IS_READ_ANY_REGISTER(op, coloring_class)) {
                     reg = op->data.reg.reg;
-                    if (bitvectorgetbit(reg, vec) == 0)
+                    if (bitvectorgetbit(op->data.reg.reg, vec) == 0)
                         op->data.reg.effect |= Effect4;
                     bitvectorsetbit(reg, vec);
                 }
diff --git a/compiler_and_linker/unsorted/PCodeAssembly.c b/compiler_and_linker/unsorted/PCodeAssembly.c
index 2c87ce3..0455d77 100644
--- a/compiler_and_linker/unsorted/PCodeAssembly.c
+++ b/compiler_and_linker/unsorted/PCodeAssembly.c
@@ -1297,7 +1297,6 @@ static void insertlongbranches(SInt32 mask) {
 
 SInt32 optimizefinalbranches(SInt32 codesize) {
     PCodeBlock *block;
-    PCodeBlock *block2;
     PCode *instr;
     SInt32 offset;
     int changed;
@@ -1337,9 +1336,9 @@ SInt32 optimizefinalbranches(SInt32 codesize) {
                 continue;
             }
 
-            if ((instr->op == PC_BT || instr->op == PC_BF) && instr->args[0].kind == PCOp_LABEL) {
-                block2 = instr->block;
-                label = instr->args[0].data.label.label;
+            if ((instr->op == PC_BT || instr->op == PC_BF) && instr->args[2].kind == PCOp_LABEL) {
+                PCodeBlock *block2 = instr->block;
+                label = instr->args[2].data.label.label;
                 target = targetinstruction(label);
 
                 if (label->block->codeOffset == (offset + 4)) {
@@ -1414,8 +1413,8 @@ SInt32 optimizefinalbranches(SInt32 codesize) {
                 !(PCODE_FLAG_SET_T(instr) & (fSideEffects | fLink))
                 )
             {
-                block2 = instr->block;
-                label = instr->args[2].data.label.label;
+                PCodeBlock *block2 = instr->block;
+                label = instr->args[3].data.label.label;
                 target = targetinstruction(label);
 
                 if (label->block->codeOffset == (offset + 4)) {
@@ -1449,7 +1448,7 @@ SInt32 optimizefinalbranches(SInt32 codesize) {
                             ) {
                             if ((val & 30) == 4)
                                 instr->args[0].data.imm.value = val | 12;
-                            else
+                            else if ((val & 30) == 12)
                                 instr->args[0].data.imm.value = val & 23;
                             instr->op = PC_BCLR;
                             instr->argCount = 3;
@@ -1470,7 +1469,7 @@ SInt32 optimizefinalbranches(SInt32 codesize) {
                             ) {
                             if ((val & 30) == 4)
                                 instr->args[0].data.imm.value = val | 12;
-                            else
+                            else if ((val & 30) == 12)
                                 instr->args[0].data.imm.value = val & 23;
                             instr->op = PC_BCCTR;
                             instr->argCount = 3;
diff --git a/compiler_and_linker/unsorted/Switch.c b/compiler_and_linker/unsorted/Switch.c
index 3b9d246..e0c99a0 100644
--- a/compiler_and_linker/unsorted/Switch.c
+++ b/compiler_and_linker/unsorted/Switch.c
@@ -335,8 +335,9 @@ static void generate_tree(ENode *expr) {
 static Object *create_switch_table(void) {
     Object *obj;
     ObjectList *list;
-    CaseRange *currange;
     UInt32 *outptr;
+    CaseRange *currange;
+    SInt32 size;
     CInt64 value;
 
     obj = galloc(sizeof(Object));
@@ -357,8 +358,9 @@ static Object *create_switch_table(void) {
     createIndirect(obj, 0, 0);
     obj->type = TYPE(&void_ptr);
 
-    obj->u.data.u.switchtable.size = CInt64_GetULong(&range) + 1;
-    obj->u.data.u.switchtable.data = lalloc(4 * obj->u.data.u.switchtable.size);
+    size = CInt64_GetULong(&range) + 1;
+    obj->u.data.u.switchtable.size = size;
+    obj->u.data.u.switchtable.data = lalloc(4 * size);
 
     currange = caseranges;
     outptr = (UInt32 *) obj->u.data.u.switchtable.data;
@@ -379,10 +381,10 @@ static Object *create_switch_table(void) {
 
 static void generate_table(ENode *expr, SwitchInfo *info) {
     Object *table;
+    SwitchCase *curcase;
     short reg;
     short reg2;
     short reg3;
-    SwitchCase *curcase;
     Operand op1;
     Operand op2;
 
@@ -406,14 +408,12 @@ static void generate_table(ENode *expr, SwitchInfo *info) {
     reg = op1.reg;
     if (CInt64_NotEqual(first, cint64_zero)) {
         SInt32 value;
-        SInt32 valueext;
         reg = ALLOC_GPR();
         value = -CInt64_GetULong(&first);
-        valueext = (SInt16) value;
-        if (value != valueext) {
+        if (!FITS_IN_SHORT(value)) {
             emitpcode(PC_ADDIS, reg, op1.reg, 0, HIGH_PART(value));
             if (value)
-                emitpcode(PC_ADDI, reg, reg, 0, valueext);
+                emitpcode(PC_ADDI, reg, reg, 0, LOW_PART(value));
         } else {
             emitpcode(PC_ADDI, reg, op1.reg, 0, value);
         }
@@ -427,7 +427,7 @@ static void generate_table(ENode *expr, SwitchInfo *info) {
         emitpcode(PC_CMPLI, 0, reg, CInt64_GetULong(&range));
     }
 
-    branch_conditional(0, EGREATER, 0, defaultlabel);
+    branch_conditional(0, EGREATER, 1, defaultlabel);
     if (table->toc) {
         op2.optype = OpndType_Symbol;
         op2.object = table->toc;
@@ -438,8 +438,7 @@ static void generate_table(ENode *expr, SwitchInfo *info) {
     }
 
     if (op2.optype != OpndType_GPR) {
-        reg2 = ALLOC_GPR();
-        Coerce_to_register(&op2, TYPE(&void_ptr), reg2);
+        Coerce_to_register(&op2, TYPE(&void_ptr), reg2 = ALLOC_GPR());
     }
 
     if (op2.optype != OpndType_GPR) {
diff --git a/includes/compiler/PCode.h b/includes/compiler/PCode.h
index 97f652d..d914748 100644
--- a/includes/compiler/PCode.h
+++ b/includes/compiler/PCode.h
@@ -11,8 +11,8 @@
 #define FLAG_SET_T(flags) (((flags) & (fIsBranch | fIsCall)) ? (flags) : 0)
 #define FLAG_SET_F(flags) (((flags) & (fIsBranch | fIsCall)) ? 0 : (flags))
 
-#define PCODE_FLAG_SET_T(pcode) (((pcode)->flags & (fIsBranch | fIsCall)) ? (pcode)->flags : 0)
-#define PCODE_FLAG_SET_F(pcode) (((pcode)->flags & (fIsBranch | fIsCall)) ? 0 : (pcode)->flags)
+#define PCODE_FLAG_SET_T(pcode) ((((PCode *) (pcode))->flags & (fIsBranch | fIsCall)) ? ((PCode *) (pcode))->flags : 0)
+#define PCODE_FLAG_SET_F(pcode) ((((PCode *) (pcode))->flags & (fIsBranch | fIsCall)) ? 0 : ((PCode *) (pcode))->flags)
 
 enum {
     EffectRead = 1,