Re: compiler warnings on the buildfarm

Alvaro Herrera wrote:
> Stefan showed me via Jabber this warning:
> 
> /tmp/ccM7MfqX.s: Assembler messages:
> /tmp/ccM7MfqX.s:703: Warning: 00000003fffffffc shortened to 00000000fffffffc
> /tmp/ccM7MfqX.s:738: Warning: 00000003fffffffc shortened to 00000000fffffffc
> 
> He says that this comes from trgm_op.c file.  I don't get the warning
> myself obviously, so I started guessing.
> 
> 3FFFFFFFC = 1111111111111111111111111111111100
>  FFFFFFFC =   11111111111111111111111111111100
> 
> So the upper 2 bits are being lost (the second number is 32 bits wide).
> 
> The only thing that I think is related is the usage of VARSIZE().  It
> looks like 0x3FFFFFFF (actual constant in the toast code) is shift two
> bits left.  I can see no such operation though.

The shift is in postgres.h, SET_VARSIZE_4B. I have no idea where that 
warning is coming from, though. What's the real source behind "ccM7MfqX.s"?

--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com