#2851 Operation order SDCC 3.8.0

[Alexey Grachov]

pos=0;
buf[pos++] = 1;

SDCC 3.6.0 gives buf[0] = 1 as result
SDCC 3.8.0 gives buf[1] = 1 as result

[Philipp Klaus Krause]

I tried to reproduce this using current SDCC [r10753] using the stm8 and pic14 backends, but couldn't. I tried:

unsigned char pos, *buf;

void f(void)
{
  pos=0;
  buf[pos++] = 1;
}

Please provide a compileable reproducer for this issue.

Philipp

[Maarten Brock]

I have also tried mcs51 and could not reproduce.

[Alexey Grachov]

Here is my code.
Changes made in eeprom.c
Build with build.sh
Results (from top to bottom):

1. sdcc 3.6.0 // ORIGINAL
2. sdcc 3.8.0 // ORIGINAL
3. sdcc 3.8.0 // FIRST
4. sdcc 3.8.0 // FIRST + SECOND
   

[Philipp Klaus Krause]

I can reproduce the issue in current SDCC. The issue also affects backends other than pic14 (I tried stm8).
I have extracted the affected function into the attached file.

Philipp

P.S.: I made a mistake. The code for stm8, mcs51 and z80 looks good. I don't know about pic14.