Compiler/TMS320C6657: CGT V7.4.21 optimization issue.(use -O3 and -O2 will cause array result error)

Denny%20Yang99373

Expert 3805 points

Part Number: TMS320C6657

Tool/software: TI C/C++ Compiler

Hi all,

Customer report a CGT issue.

Attached is the project can run on C6657 EVM.

If use -O0 or -O1 the sig_out[255] is 0xBC, it's right.

If use -O2 or -O3, the sig_out[255] is 0xB5. it's wrong.

-O3 picture:

-O0 picture:

And this is the attached project. I have checked, the CGT V7.4.20 and CGT V8.1.0 also have this issue. please help me the debug it, thanks!

testUn.7z

BR,
Denny

over 8 years ago

0 AartiG over 8 years ago

TI__Guru**** 173310 points

Denny,

I will try to reproduce this issue and get back to you. In the meantime, could you try out CGT 8.1.4 to see if the results are the same?

You can install C6000 compiler v8.1.4 through CCS by going to menu Help->Check for Updates. After installing it, you can tell CCS to use that version of the compiler for build from within the Project Properties.

0 Archaeologist over 8 years ago

TI__Guru* 84225 points

When I run the program on Linux using gcc-5, it shows that sig_out[255] is 0x26, which does not agree with either answer. Are you sure 0xBC is the proper answer?

0 Denny%20Yang99373 over 8 years ago in reply to AartiG

TI__Expert 3805 points

Hi AaritG,

I have tried v8.1.4, it's same.

BR,
Denny

0 Denny%20Yang99373 over 8 years ago in reply to Archaeologist

TI__Expert 3805 points

Hi archaeologist,

Maybe you should set enough stack and heap size.

BR,
Denny

0 AartiG over 8 years ago in reply to Denny%20Yang99373

TI__Guru**** 173310 points

Denny,

From what I see (and per your screenshot as well), it is not just the value of sig_out[255] that is different, but all or at least many of the other sig_out values as well. Is that accurate?

Has it been verified that the values obtained with -o0/-o1 are the correct values?

0 Denny%20Yang99373 over 8 years ago in reply to AartiG

TI__Expert 3805 points

AartiG,

Yes, Not only sig_out[255] is different. Customer only use sig_out[255] now, so I make it as example.

It have been verified that -o0/o1 array has correct values.

BR,
Denny

0 AartiG over 8 years ago in reply to Denny%20Yang99373

TI__Guru**** 173310 points

Denny,

I filed this issue for analysis, the tracking number is CODEGEN-2346. Feel free to track its status using the SDOWP link in my signature (after giving some time for the link to get populated).