Incorrect processing of arithmetic (SETA) expresions when overflow occurs

[jyganci]

The z390 processing of arithmetic expressions does not properly handle conditions when arithmetic overflow occurs. Following examples of the form (1) set LCLA symbol &A to initial valid value (2) Attempt to set &A to invalid value (3) MNOTE the final value of &A. Both HLASM and z390 results are shown for four examples.

Note the two arithmetic overflows and the two multiplicatoin overflows in HLASM. No errors in z390.

HLASM
                                      49 *************************
                                      50 * &A SET TO 0
                                      51 *
                                      52 &A       SETA  1
                                      53 *
                                      54 *&A      SETA  2147483647+3
                                      55 &A       SETA  2147483647+3
 ** ASMA075E Arithmetic overflow
                                      56 &SA      SETC  SIGNED(&A)
                                      57          MNOTE '&&A=&SA'
                                        +&A=0
                                      58 *
                                      59 &A       SETA  1
                                      60 *
                                      61 *&A      SETA  -2147483648-3
                                      62 &A       SETA  -2147483648-3
 ** ASMA075E Arithmetic overflow
                                      63 &SA      SETC  SIGNED(&A)
                                      64          MNOTE '&&A=&SA'
                                        +&A=0
                                      65 *
                                      66 *************************
                                      67 * &A SET TO 1
                                      68 *
                                      69 &A       SETA  2
                                      70 *
                                      71 *&A      SETA  2*2147483647
                                      72 &A       SETA  2*2147483647
 ** ASMA103E Multiplication overflow; default product=1 - OPENC
                                      73 &SA      SETC  SIGNED(&A)
                                      74          MNOTE '&&A=&SA'
                                        +&A=1
                                      75 *
                                      76 *************************
                                      77 * &A SET TO -2
                                      78 *
                                      79 &A       SETA  1
                                      80 *
                                      81 *&A      SETA  2*1024*1024*1024-3
                                      82 &A       SETA  2*1024*1024*1024-3
 ** ASMA103E Multiplication overflow; default product=1 - OPENC
                                      83 &SA      SETC  SIGNED(&A)
                                      84          MNOTE '&&A=&SA'
                                        +&A=-2
                                      85 *
                                      86 *************************

z390
000000                                      (1/49)39 *************************
000000                                      (1/50)40 * &A SET TO 0
000000                                      (1/51)41 *
000000                                      (1/53)42 *
000000                                      (1/54)43 *&A      SETA  2147483647+3
000000                                      (1/57)44          MNOTE '&A=-2147483646'
000000                                      (1/58)45 *
000000                                      (1/60)46 *
000000                                      (1/61)47 *&A      SETA  -2147483648-3
000000                                      (1/64)48          MNOTE '&A=2147483645'
000000                                      (1/65)49 *
000000                                      (1/66)50 *************************
000000                                      (1/67)51 * &A SET TO 1
000000                                      (1/68)52 *
000000                                      (1/70)53 *
000000                                      (1/71)54 *&A      SETA  2*2147483647
000000                                      (1/74)55          MNOTE '&A=-2'
000000                                      (1/75)56 *
000000                                      (1/76)57 *************************
000000                                      (1/77)58 * &A SET TO -2
000000                                      (1/78)59 *
000000                                      (1/80)60 *
000000                                      (1/81)61 *&A      SETA  2*1024*1024*1024-3
000000                                      (1/84)62          MNOTE '&A=2147483645'
000000                                      (1/85)63 *
000000                                      (1/86)64 *************************

Two existing z390 regression tests, rt/mlc/TESTDC1.MLC and rt/mlc/TESTASC1.MLC have tests that currently do not produce errors but should if z390 is corrected to match HLASM behavior. Comments about this problem appear in the source of the 2 programs.

The code in mz390.java (and possibly az390.java) should correctly process arithmetic expressions, detecting and reporting any overflow errors.