Merge pull request #366 from dbrotz/fix-313

Fix signed integer overflow issues

test/asm/overflow.asm

@@ -0,0 +1,42 @@
+SECTION "sec", ROM0
+
+print_x: MACRO
+	printv x
+	printt "\n"
+ENDM
+
+x = 2147483647
+x = x + 1
+	dl 2147483647+1
+	print_x
+
+x = -2147483648
+x = x - 1
+	dl -2147483648-1
+	print_x
+
+x = -2147483648
+x = x * -1
+	dl -2147483648 * -1
+	print_x
+
+x = -2147483648
+x = x / -1
+	dl -2147483648 / -1
+	print_x
+
+x = -2147483648
+x = x % -1
+	dl -2147483648 % -1
+	print_x
+
+x = -1
+x = x << 1
+	dl -1 << 1
+	print_x
+
+x = 4294967295
+x = 4294967296
+
+x = `33333333
+x = `333333333

test/asm/overflow.out

@@ -0,0 +1,18 @@
+warning: overflow.asm(24):
+    Division of min value by -1
+warning: overflow.asm(25):
+    Division of min value by -1
+warning: overflow.asm(34):
+    Left shift of negative value: -1
+warning: overflow.asm(35):
+    Left shift of negative value: -1
+warning: overflow.asm(39):
+    Integer constant '4294967296' is too large
+warning: overflow.asm(42):
+    Graphics constant '`333333333' is too long
+$80000000
+$7FFFFFFF
+$80000000
+$80000000
+$0
+$FFFFFFFE

test/asm/overflow.out.pipe

@@ -0,0 +1,18 @@
+warning: -(24):
+    Division of min value by -1
+warning: -(25):
+    Division of min value by -1
+warning: -(34):
+    Left shift of negative value: -1
+warning: -(35):
+    Left shift of negative value: -1
+warning: -(39):
+    Integer constant '4294967296' is too large
+warning: -(42):
+    Graphics constant '`333333333' is too long
+$80000000
+$7FFFFFFF
+$80000000
+$80000000
+$0
+$FFFFFFFE