To: vim_dev@googlegroups.com Subject: Patch 8.2.5004 Fcc: outbox From: Bram Moolenaar Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit ------------ Patch 8.2.5004 Problem: Right shift on negative number does not work as documented. Solution: Use a uvarnumber_T type cast. Files: runtime/doc/eval.txt, src/eval.c, src/vim9expr.c, src/vim9execute.c, src/charset.c, src/testdir/test_expr.vim *** ../vim-8.2.5003/runtime/doc/eval.txt 2022-05-22 19:13:45.496327034 +0100 --- runtime/doc/eval.txt 2022-05-22 20:14:04.001311133 +0100 *************** *** 1138,1146 **** *E1282* *E1283* The "<<" and ">>" operators can be used to perform bitwise left or right shift of the left operand by the number of bits specified by the right operand. The ! operands must be positive numbers. The topmost bit (sign bit) is always ! cleared for ">>". If the right operand (shift amount) is more than the ! maximum number of bits in a number (|v:numbersize|) the result is zero. expr6 and expr7 *expr6* *expr7* *E1036* *E1051* --- 1138,1147 ---- *E1282* *E1283* The "<<" and ">>" operators can be used to perform bitwise left or right shift of the left operand by the number of bits specified by the right operand. The ! operands are used as positive numbers. When shifting right with ">>" the ! topmost bit (somtimes called the sign bit) is cleared. If the right operand ! (shift amount) is more than the maximum number of bits in a number ! (|v:numbersize|) the result is zero. expr6 and expr7 *expr6* *expr7* *E1036* *E1051* *************** *** 1417,1422 **** --- 1418,1427 ---- Decimal, Hexadecimal (starting with 0x or 0X), Binary (starting with 0b or 0B) and Octal (starting with 0, 0o or 0O). + Assuming 64 bit numbers are used (see |v:numbersize|) an unsigned number is + truncated to 0x7fffffffffffffff or 9223372036854775807. You can use -1 to get + 0xffffffffffffffff. + *floating-point-format* Floating point numbers can be written in two forms: *** ../vim-8.2.5003/src/eval.c 2022-05-22 19:13:45.496327034 +0100 --- src/eval.c 2022-05-22 19:20:46.928504419 +0100 *************** *** 3091,3102 **** rettv->vval.v_number = rettv->vval.v_number << var2.vval.v_number; else - { rettv->vval.v_number = ! rettv->vval.v_number >> var2.vval.v_number; ! // clear the topmost sign bit ! rettv->vval.v_number &= ~((uvarnumber_T)1 << MAX_LSHIFT_BITS); ! } } clear_tv(&var2); --- 3091,3098 ---- rettv->vval.v_number = rettv->vval.v_number << var2.vval.v_number; else rettv->vval.v_number = ! (uvarnumber_T)rettv->vval.v_number >> var2.vval.v_number; } clear_tv(&var2); *** ../vim-8.2.5003/src/vim9expr.c 2022-05-22 19:13:45.500327035 +0100 --- src/vim9expr.c 2022-05-22 19:25:26.640619364 +0100 *************** *** 2719,2729 **** else if (type == EXPR_LSHIFT) tv1->vval.v_number = tv1->vval.v_number << tv2->vval.v_number; else ! { ! tv1->vval.v_number = tv1->vval.v_number >> tv2->vval.v_number; ! // clear the topmost sign bit ! tv1->vval.v_number &= ~((uvarnumber_T)1 << MAX_LSHIFT_BITS); ! } clear_tv(tv2); --ppconst->pp_used; } --- 2719,2726 ---- else if (type == EXPR_LSHIFT) tv1->vval.v_number = tv1->vval.v_number << tv2->vval.v_number; else ! tv1->vval.v_number = ! (uvarnumber_T)tv1->vval.v_number >> tv2->vval.v_number; clear_tv(tv2); --ppconst->pp_used; } *** ../vim-8.2.5003/src/vim9execute.c 2022-05-22 19:13:45.500327035 +0100 --- src/vim9execute.c 2022-05-22 19:21:57.620533615 +0100 *************** *** 4096,4107 **** case EXPR_RSHIFT: if (arg2 > MAX_LSHIFT_BITS) res = 0; else ! { ! res = arg1 >> arg2; ! // clear the topmost sign bit ! res &= ~((uvarnumber_T)1 ! << MAX_LSHIFT_BITS); ! } break; default: break; } --- 4096,4102 ---- case EXPR_RSHIFT: if (arg2 > MAX_LSHIFT_BITS) res = 0; else ! res = (uvarnumber_T)arg1 >> arg2; break; default: break; } *** ../vim-8.2.5003/src/charset.c 2022-05-21 20:16:51.003567195 +0100 --- src/charset.c 2022-05-22 19:57:32.935030889 +0100 *************** *** 2002,2007 **** --- 2002,2008 ---- } else { + // prevent a larg unsigned number to become negative if (un > VARNUM_MAX) un = VARNUM_MAX; *nptr = (varnumber_T)un; *** ../vim-8.2.5003/src/testdir/test_expr.vim 2022-05-22 19:13:45.500327035 +0100 --- src/testdir/test_expr.vim 2022-05-22 19:48:17.396918194 +0100 *************** *** 958,963 **** --- 958,965 ---- call assert_equal(0, 0 >> 4) call assert_equal(0, 999999 >> 100) call assert_equal(0, 999999 << 100) + call assert_equal(-1, -1 >> 0) + call assert_equal(-1, -1 << 0) VAR a = 8 VAR b = 2 call assert_equal(2, a >> b) *************** *** 976,981 **** --- 978,992 ---- for i in range(0, v:numbersize - 2) LET val = and(val, invert(1 << i)) endfor + #" -1 has all the bits set + call assert_equal(-2, -1 << 1) + call assert_equal(-4, -1 << 2) + call assert_equal(-8, -1 << 3) + if v:numbersize == 64 + call assert_equal(0x7fffffffffffffff, -1 >> 1) + call assert_equal(0x3fffffffffffffff, -1 >> 2) + call assert_equal(0x1fffffffffffffff, -1 >> 3) + endif call assert_equal(0, val) #" multiple operators call assert_equal(16, 1 << 2 << 2) *** ../vim-8.2.5003/src/version.c 2022-05-22 19:13:45.500327035 +0100 --- src/version.c 2022-05-22 19:26:47.328652290 +0100 *************** *** 736,737 **** --- 736,739 ---- { /* Add new patch number below this line */ + /**/ + 5004, /**/ -- hundred-and-one symptoms of being an internet addict: 267. You get an extra phone line so you can get phone calls. /// Bram Moolenaar -- Bram@Moolenaar.net -- http://www.Moolenaar.net \\\ /// \\\ \\\ sponsor Vim, vote for features -- http://www.Vim.org/sponsor/ /// \\\ help me help AIDS victims -- http://ICCF-Holland.org ///