[sdcc-devel] [ sdcc-Bugs-1068154 ] unsigned multiplication 8bit x 8bit --> 16 bit fails

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Bugs item #1068154, was opened at 2004-11-17 17:40
Message generated for change (Comment added) made by tecodev
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=100599&aid=1068154&group_id=599

Category: pic16 target
Group: None
Status: Open
Resolution: None
Priority: 5
Submitted By: ccsporters (tecodev)
Assigned to: Nobody/Anonymous (nobody)
Summary: unsigned multiplication 8bit x 8bit --> 16 bit fails

Initial Comment:
Mutliplication of two 8 bit numbers with a desired
16/32 bit result fails to initialize/assign to the
higher result bytes.
This also causes failures when accessing (2
dimensional) arrays like:

<code>
typedef unsigned char byte;

byte large_data[3][4] = {
  {1,2,3,4}, {6,7,8,9}, {8,7,6,5}
};

byte demo1 (byte a, byte b) {
  return large_data[a][b];
}

int main () {
  demo1(2,4);
}
</code>

The errors are located in genarith.c,
pic16_genUMult8XLit_8() and are resolved (hopefully) by
the attached patch.

Raphael Neider


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>Comment By: ccsporters (tecodev)
Date: 2004-11-17 18:03

Message:
Logged In: YES 
user_id=1115835

My last patch had a typo -- new fix available...

Raphael Neider

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

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=100599&aid=1068154&group_id=599