tree to rtl conversion optimizations

[Jim Wilson]

Johnny Huynh wrote:
Sorry if this sounds like a simple question, but I'm not too good at
tracing through all the source yet. During the conversion from tree to
RTL, there seems to be an optimizing step that determines whether
operands should be placed (-O0) in memory and accessed via an offset, or
(-O2) simply placed in registers.
See the optimize test in expand_decl in stmt.c.

The compiler should still work fine if you disable this, so that all 
local variables end up in stack slots.

There might be other places in the code that are putting variables into 
pseudo regs.
--
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com