Merge pull request #473 from ISSOtm/shift_ub

Remove undefined behavior from shifts

test/asm/overflow.err

@@ -2,10 +2,8 @@ warning: overflow.asm(24): [-Wdiv]
     Division of min value by -1
 warning: overflow.asm(25): [-Wdiv]
     Division of min value by -1
-warning: overflow.asm(34): [-Wshift]
-    Left shift of negative value: -1
 warning: overflow.asm(35): [-Wshift]
-    Left shift of negative value: -1
+    Shifting negative value -1
 warning: overflow.asm(39): [-Wlarge-constant]
     Integer constant '4294967296' is too large
 warning: overflow.asm(42): [-Wlarge-constant]

test/asm/shift.asm

@@ -0,0 +1,27 @@
+test: macro
+	; Test the rpn system, as well as the linker...
+	dl \1 + zero
+
+	; ...as well as the constexpr system
+result\@ equ \1
+	printt "\1 = {result\@}\n"
+endm
+
+section "test", ROM0[0]
+
+	test 1 << 1
+	test 1 << 32
+	test 1 << 9001
+	test -1 << 1
+	test -1 << 32
+	test -1 << -9001
+
+	test -1 >> 1
+	test -1 >> 32
+	test -1 >> 9001
+	test -4 >> 1
+	test -4 >> 2
+	test -1 >> -9001
+
+SECTION "Zero", ROM0[0]
+zero:

test/asm/shift.err

@@ -0,0 +1,66 @@
+warning: shift.asm(13) -> shift.asm::test(3): [-Wshift-amount]
+    Shifting left by large amount 32
+warning: shift.asm(13) -> shift.asm::test(6): [-Wshift-amount]
+    Shifting left by large amount 32
+warning: shift.asm(14) -> shift.asm::test(3): [-Wshift-amount]
+    Shifting left by large amount 9001
+warning: shift.asm(14) -> shift.asm::test(6): [-Wshift-amount]
+    Shifting left by large amount 9001
+warning: shift.asm(15) -> shift.asm::test(3): [-Wshift]
+    Shifting negative value -1
+warning: shift.asm(16) -> shift.asm::test(3): [-Wshift]
+    Shifting negative value -1
+warning: shift.asm(16) -> shift.asm::test(3): [-Wshift-amount]
+    Shifting left by large amount 32
+warning: shift.asm(16) -> shift.asm::test(6): [-Wshift-amount]
+    Shifting left by large amount 32
+warning: shift.asm(17) -> shift.asm::test(3): [-Wshift-amount]
+    Shifting left by negative value: -9001
+warning: shift.asm(17) -> shift.asm::test(3): [-Wshift]
+    Shifting negative value -1
+warning: shift.asm(17) -> shift.asm::test(3): [-Wshift-amount]
+    Shifting right by large amount 9001
+warning: shift.asm(17) -> shift.asm::test(6): [-Wshift-amount]
+    Shifting left by negative amount -9001
+warning: shift.asm(17) -> shift.asm::test(6): [-Wshift-amount]
+    Shifting right by large amount 9001
+warning: shift.asm(19) -> shift.asm::test(3): [-Wshift]
+    Shifting negative value -1
+warning: shift.asm(19) -> shift.asm::test(6): [-Wshift]
+    Shifting negative value -1
+warning: shift.asm(20) -> shift.asm::test(3): [-Wshift]
+    Shifting negative value -1
+warning: shift.asm(20) -> shift.asm::test(3): [-Wshift-amount]
+    Shifting right by large amount 32
+warning: shift.asm(20) -> shift.asm::test(6): [-Wshift]
+    Shifting negative value -1
+warning: shift.asm(20) -> shift.asm::test(6): [-Wshift-amount]
+    Shifting right by large amount 32
+warning: shift.asm(21) -> shift.asm::test(3): [-Wshift]
+    Shifting negative value -1
+warning: shift.asm(21) -> shift.asm::test(3): [-Wshift-amount]
+    Shifting right by large amount 9001
+warning: shift.asm(21) -> shift.asm::test(6): [-Wshift]
+    Shifting negative value -1
+warning: shift.asm(21) -> shift.asm::test(6): [-Wshift-amount]
+    Shifting right by large amount 9001
+warning: shift.asm(22) -> shift.asm::test(3): [-Wshift]
+    Shifting negative value -4
+warning: shift.asm(22) -> shift.asm::test(6): [-Wshift]
+    Shifting negative value -4
+warning: shift.asm(23) -> shift.asm::test(3): [-Wshift]
+    Shifting negative value -4
+warning: shift.asm(23) -> shift.asm::test(6): [-Wshift]
+    Shifting negative value -4
+warning: shift.asm(24) -> shift.asm::test(3): [-Wshift-amount]
+    Shifting right by negative value: -9001
+warning: shift.asm(24) -> shift.asm::test(3): [-Wshift]
+    Shifting negative value -1
+warning: shift.asm(24) -> shift.asm::test(3): [-Wshift-amount]
+    Shifting left by large amount 9001
+warning: shift.asm(24) -> shift.asm::test(6): [-Wshift-amount]
+    Shifting right by negative amount -9001
+warning: shift.asm(24) -> shift.asm::test(6): [-Wshift]
+    Shifting negative value -1
+warning: shift.asm(24) -> shift.asm::test(6): [-Wshift-amount]
+    Shifting left by large amount 9001

test/asm/shift.out

@@ -0,0 +1,12 @@
+1 << 1 = $2
+1 << 32 = $0
+1 << 9001 = $0
+-1 << 1 = $FFFFFFFE
+-1 << 32 = $0
+-1 << -9001 = $FFFFFFFF
+-1 >> 1 = $FFFFFFFF
+-1 >> 32 = $FFFFFFFF
+-1 >> 9001 = $FFFFFFFF
+-4 >> 1 = $FFFFFFFE
+-4 >> 2 = $FFFFFFFF
+-1 >> -9001 = $0