C2000 Optimization Option brings some problem

It is not unusual that the assembly output is different in those two cases.  I don't see how those two assembly sequences can compute a different result.

But to do better analysis, we need a test case which allows us to generate the same assembly.  Please send in the preprocessed form of the source file which contains this code.  Indicate, in the preprocessed file, the location of the problem lines.  And show all the build options exactly as the compiler sees them.

Thanks and regards,

-George

The line by line analysis of the left assembly code reveals that it has a problem.

iTest102 = pTraceData[cntTest*2 - 2];

is translated into

        MOVW      DP,#_cntTest           ;(1)
        MOV       AL,@_cntTest            ; (2)
        ADD       AL,#32767                 ; (3) 
        MOVU      ACC,AL                    ;(4)
        LSL       ACC,1                          ; (5)
        ADDL      XAR4,ACC                 ;(6)
        MOVW      DP,#_iTest102          ;(7)
        MOV       AH,*+XAR4[0]            ; (8)
        MOV       @_iTest102,AH         ; (9)

XAR4 is used as the address of pTraceData[cntTest*2 -2].

Originally, XAR4 has the value of the address of pTraceData[0].

By ADDL XAR4,ACC, XAR4 is supposed to have the address of pTraceData[cntTest*2 -2].

But from the following analysis, it shows that XAR4 has a wrong value.

At (4), ACC = cntTest + 32767

At (5), ACC = (cntTest + 32767)<<1

At (6), XAR4 = &pTraceData[0] + (cntTest + 32767)<<1

But, (cntTest + 32767)<<1 is different from cntTest*2 - 2, which is the programmed in the C code.

(cntTest+32767)<<1 = (cntTest+0x7fff)<<1 = (cntTest + 0x8000 – 1)*2 = cntTest*2 -2 + 0x10000 , which is incorrect,

Is there a compiler which fixes this bug or any workaround?

Compile options are

Options=--preproc_only --preproc_with_compile Option -k -o3 --symdebug:coff -q -pr -pdv -pden -pds9 -pds190 -pds188 -fr".\Release" -i".\include" -i"C:\ti\c2000\cgtools_311\include" -d"LARGE_MODEL" -ml -v28

Here's the preprocessed C code and the assembly code.

int iArray10[10];
unsigned int iIdx;
int iValTest1;

void test()
{
iValTest1 = iArray10[iIdx*2 -2];
}

;***************************************************************
;* TMS320C2000 C/C++ Codegen                         PC v6.4.9 *
;* Date/Time created: Tue May 03 09:45:00 2016                 *
;***************************************************************
 .compiler_opts --float_support=softlib --hll_source=on --mem_model:code=flat --mem_model:data=large --object_format=coff --quiet --silicon_version=28 --symdebug:coff
FP .set XAR2
 .file "test.c"
 .global _iIdx
_iIdx: .usect ".ebss",1,1,0
 .sym _iIdx,_iIdx, 14, 2, 16
 .global _iValTest1
_iValTest1: .usect ".ebss",1,1,0
 .sym _iValTest1,_iValTest1, 4, 2, 16
 .global _iArray10
_iArray10: .usect ".ebss",10,1,0
 .sym _iArray10,_iArray10, 52, 2, 160,, 10
; D:\setup\TI\CCS\ti-cgt-c2000_6.4.9\bin\opt2000.exe C:\\Users\\ewlee\\AppData\\Local\\Temp\\044362 C:\\Users\\ewlee\\AppData\\Local\\Temp\\044364
; D:\setup\TI\CCS\ti-cgt-c2000_6.4.9\bin\ac2000.exe -@C:\\Users\\ewlee\\AppData\\Local\\Temp\\0443612
 .sect ".text"
 .clink
 .global _test
 .sym _test,_test, 32, 2, 0
 .func 13

;***************************************************************
;* FNAME: _test                         FR SIZE:   0           *
;*                                                             *
;* FUNCTION ENVIRONMENT                                        *
;*                                                             *
;* FUNCTION PROPERTIES                                         *
;*                            0 Parameter,  0 Auto,  0 SOE     *
;***************************************************************

_test:
        MOVW      DP,#_iIdx             ; [CPU_U]
        CLRC      SXM                   ; [CPU_]
 .line 3
        MOV       AL,@_iIdx             ; [CPU_] |15|
        MOVL      XAR4,#_iArray10       ; [CPU_U] |15|
        ADD       AL,#32767             ; [CPU_] |15|
        MOV       ACC,AL << 1           ; [CPU_] |15|
        ADDL      XAR4,ACC              ; [CPU_] |15|
        MOV       AL,*+XAR4[0]          ; [CPU_] |15|
        MOV       @_iValTest1,AL        ; [CPU_] |15|
        LRETR     ; [CPU_]
        ; return occurs ; []
 .endfunc 16,000000000h,0

;***************************************************************
;* TYPE INFORMATION                                            *
;***************************************************************