topic Re: S32DS PowerPC 1.1: Serious linker bug in S32 Design Studio

S32DS PowerPC 1.1: Serious linker bug

bastian_schick — Fri, 17 Feb 2017 13:21:42 GMT

there is a bug in the linker doing symbol fixup.

I have following code:

e_lis r2,ext_label@ha

e_add2i. r2,ext_label@l

The generated opcodes are correct, but after linking (I guess it depend on the actual value of the label) I get (here it is 0xb0c):

e_lis r2, 0

e_add2i. r18,0x30c

----------------

The linker does simply replace the low-word of the opcode by "0xb0c", but the immediate is spread all over the opcode!

Re: S32DS PowerPC 1.1: Serious linker bug

bastian_schick — Fri, 17 Feb 2017 14:16:49 GMT

Another fix-up bug:

In my code, sc_modules is a 0x400000000 (internal RAM)

e_add2is r4,sc_modules@ha

The linker produces

e_add2is r4,0x2000

So far, PowerPC GCC for VLE is not really usable. :smileysad:

Re: S32DS PowerPC 1.1: Serious linker bug

jiri_kral — Mon, 20 Feb 2017 09:37:05 GMT

Hi,

thank you a lot for your discovery and report - I can confirm that this is a bug and for e_add2i. instruction is generated bad opcode (bad target register address). I'm going to create ticket for compiler team.

As a workaround you can use OR instruction instead ADD:

e_lis r4, ext_label@h
e_or2i r4, ext_label@l

Jiri

Re: S32DS PowerPC 1.1: Serious linker bug

bastian_schick — Mon, 20 Feb 2017 09:44:26 GMT

Hi Jiri,

thanks for filing this as a bug.

But e_or2i is no suitable replacement, as it does not set flags. Same for e_add16i

Cheers

Re: S32DS PowerPC 1.1: Serious linker bug

jiri_kral — Mon, 20 Feb 2017 12:37:19 GMT

Hi,

quick update - this bug will be fixed in next (ver 1.2) S32DS release - planned for the end of Q1 or beginning of the Q2.

Jiri

Re: S32DS PowerPC 1.1: Serious linker bug

bastian_schick — Tue, 21 Feb 2017 10:18:40 GMT

If the sources would be public available, I could maybe fix it myself.

I think S32DS and GCC should be separated.