How does GCC4 transform GIMPLE IR to SSA?

How does GCC4 transform GIMPLE IR to SSA?

[QiangHuang]

Hi all:

I'm trying to understand GCC 4 as part of my research,especially the
SSA form in this compiler.I have read some literatures about SSA
form,and get the ouput in the form of SSA from GCC.

But for more details,I need to know the exact procedures how GIMPLE
form is transformed into SSA.Thus, I wonder that if someone could show
me the transformation flow or something related.

Thanks in advance.

Re: How does GCC4 transform GIMPLE IR to SSA?

[Diego Novillo]

On 03/23/08 10:09, QiangHuang wrote:

> But for more details,I need to know the exact procedures how GIMPLE
> form is transformed into SSA.Thus, I wonder that if someone could show
> me the transformation flow or something related.

There are tutorials, presentations and articles on GCC internals in the 
GCC wiki, http://gcc.gnu.org/wiki/GettingStarted

The source code for the SSA renamer is tree-into-ssa.c.  Note that GCC 
uses two SSA forms, the traditional rewriting form for scalars and a 
non-rewriting factored use-def chains for memory variables.  Both are 
implemented in tree-into-ssa.c.

I recommend that you read about virtual operands and memory SSA 
representation in the articles and tutorials.


Diego.