Fixing bug in RSHIFT.

common/base_tests.fs

@@ -129,3 +129,12 @@ e: test-?dup
   0 ?dup 0 =assert
   depth 0 =assert
 ;e
+
+e: test-lshift
+  $1234 4 lshift $12340 =assert
+;e
+
+e: test-rshift
+  $1234 4 rshift $123 =assert
+  -1 cell 8 * 1- rshift 1 =assert
+;e

common/opcodes.h

@@ -82,7 +82,7 @@ typedef struct {
                     tos = (ucell_t) w / (ucell_t) tos) \
   X("*/MOD", SSMOD, SSMOD_FUNC) \
   Y(LSHIFT, tos = (*sp-- << tos)) \
-  Y(RSHIFT, tos = (*sp-- >> tos)) \
+  Y(RSHIFT, tos = (((ucell_t) *sp--) >> tos)) \
   Y(AND, tos &= *sp--) \
   Y(OR, tos |= *sp--) \
   Y(XOR, tos ^= *sp--) \