duskos

commit 3c2d8e25bd89d32c7312fcd5bc7328d87157b2c4
parent d15f3d5b34d43f255136f897ee0cde301c9dc30f
Author: Virgil Dupras <hsoft@hardcoded.net>
Date:   Sun, 13 Nov 2022 13:27:50 -0500

cc: fix bug in pointer arithmetics

Diffstat:
M
fs/cc/vm/commonhi.fs
 | 
1
+
M
fs/tests/cc/cc.fs
 | 
1
+
M
fs/tests/cc/test.c
 | 
5
+++++

3 files changed, 7 insertions(+), 0 deletions(-)
diff --git a/fs/cc/vm/commonhi.fs b/fs/cc/vm/commonhi.fs
@@ -52,6 +52,7 @@ ARIOPCNT wordtbl constops ( n n -- n )
 \ vm-, is special because it handles the special "pointer-pointer" situation.
 : vm-, _ptrariadj vmop :typeptr? vmop^ :typeptr? and if
     vmop :*arisz typesize>pow2 1 ( - ) _ariop, ( shr ) vmop :>>n
+    TYPE_INT to vmop type
     else 1 ( - ) _ariop, then ;
 
 : _assignop, vmop :isconst? not _assert assignop, ;
diff --git a/fs/tests/cc/cc.fs b/fs/tests/cc/cc.fs
@@ -32,6 +32,7 @@ exprparens 9 #eq
 cnoop ( no result! ) scnt 0 #eq
 42 ptrari 50 #eq
 42 50 ptrari2 2 #eq
+42 50 ptrari3 46 #eq
 array 52 #eq
 global 1234 #eq
 globalinc 1236 #eq
diff --git a/fs/tests/cc/test.c b/fs/tests/cc/test.c
@@ -127,6 +127,11 @@ int* ptrari(int *x) {
 int ptrari2(int *lo, int *hi) {
     return hi-lo;
 }
+// when subtracting 2 pointers, the result is considered a scalar for the
+// remainder of the expression.
+int* ptrari3(int *lo, int *hi) {
+    return lo+((hi-lo)/2);
+}
 int array() {
     int a[3] = {42, 12, 2};
     return *a + a[1] - *(a+2);