Re: ARM constant folding bug?

2007-08-03 Thread Jonathan S. Shapiro
On Fri, 2007-08-03 at 10:34 -0700, Nathan Froyd wrote: > On Fri, Aug 03, 2007 at 06:24:06PM +0100, Paul Brook wrote: > > On Friday 03 August 2007, Jonathan S. Shapiro wrote: > > > Then it seems very curious that the constant folding should fail on this > > > platform.

Link start address

2007-08-03 Thread Jonathan S. Shapiro
This is probably a question that should be directed to the binutils list. We need to set the default link start address used by ld. Unfortunately ld doesn't have a nice porting guide like GCC does. :-) Actually, we need to choose one of two possible start addresses based on command line options t

Re: ARM constant folding bug?

2007-08-03 Thread Jonathan S. Shapiro
On Fri, 2007-08-03 at 12:46 -0400, Daniel Jacobowitz wrote: > On Fri, Aug 03, 2007 at 05:24:28PM +0100, Dave Korn wrote: > > I'm a bit surprised too. But it occurs to me that the ARM, unlike the > > i386 > > and m68k, is bi-endian. Perhaps you can't actually know which mode it's > > running in

Re: GCC compile models -- theory of operation?

2007-08-03 Thread Jonathan S. Shapiro
Ian: Thanks for the explanation of eh-frame-header. All of what you say makes sense. Before I dig in to this, is the eh-frame-header stuff documented somewhere? If so I should read that as well. shap

RE: ARM constant folding bug?

2007-08-03 Thread Jonathan S. Shapiro
On Fri, 2007-08-03 at 17:24 +0100, Dave Korn wrote: > > I am not surprised that there is different behavior for different > > targets, but I am very surprised that *this* behavior is different. This > > optimization ought to be happening in the mid-end, and it ought to be > > entirely machine inde

ARM constant folding bug?

2007-08-03 Thread Jonathan S. Shapiro
This is observed on gcc-3.4.6. It may be a known issue, and/or it may be fixed in later compilers. For bringup purposes, I wrote an inline assembly hack to get the cross compiler to tell me whether the target is little/big endian. The code fragment is: const unsigned long ul = 0x04030201llu;

Re: GCC compile models -- theory of operation?

2007-08-03 Thread Jonathan S. Shapiro
First, thanks to Dave and Daniel for taking the time to reply. On Fri, 2007-08-03 at 11:06 -0400, Daniel Jacobowitz wrote: > crtbeginT.o is used for -static; crtbegin.o is used without -static. > I don't recall why they have to be different. So far as we can tell from looking at the linux versio

RE: GCC compile models -- theory of operation?

2007-08-03 Thread Jonathan S. Shapiro
On Fri, 2007-08-03 at 15:58 +0100, Dave Korn wrote: > On 03 August 2007 15:48, Jonathan S. Shapiro wrote: > > > 2. Is there a simple way to configure the compiler so that the default > > compilation model (in the absence of command-line directives) is > > --static? If n

GCC compile models -- theory of operation?

2007-08-03 Thread Jonathan S. Shapiro
We're targeting a new OS with GCC. I've done some of these before, but I've run into one issue I don't recognize, and a second that I have obviously messed up. I have looked at "Using and Porting" and "GCC Internals". The answers may be there, but I did not find them -- pointers welcome. 1. Versi