Re: java/1159

[green at gcc dot gnu dot org]

The following reply was made to PR java/1159; it has been noted by GNATS.

From: green@gcc.gnu.org
To: apbianco@gcc.gnu.org, bryce@albatross.co.nz, gcc-gnats@gcc.gnu.org
Cc:  
Subject: Re: java/1159
Date: 23 Dec 2000 20:09:32 -0000

 Synopsis: Source parser miscompiles loops when using "-O"
 
 State-Changed-From-To: open->analyzed
 State-Changed-By: green
 State-Changed-When: Sat Dec 23 12:09:32 2000
 State-Changed-Why:
     You can work around this bug by compiling with -fno-defer-pop.
     
     The defer-pop docs say:
     Always pop the arguments to each function call as soon as that function
     returns.  For machines which must pop arguments after a function call,
     the compiler normally lets arguments accumulate on the stack for several
     function calls and pops them all at once.
     
     
     Compare "gcj -O0 -fdefer-pops -S Loop.java" with
     "gcj -O0 -fno-defer-pops -S Loop.java".
     If you look at the asm code for the method calls within 
     our loop, you'll see that we're popping the stack twice (once after each function call, and the second time at the end of the loop)!
 
 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view&pr=1159&database=gcc