Canonicalization
Implement the
IRCanonicalize component that transforms
IntermediateRepresentation expressions into canonical form. The component can be found in directory
ir/ of the
TigerTrans package. The component can be invoked using the
%.cir target in the make-rules.
Lifting Functions
During translation nested function declarations where left in place and translated to the
LET construct. Since addition of
static links to functions makes functions independent of their
static position, their declarations can be lifted to top-level.
Lifting can be done nicely using
collect-split. See module
list-set in the
StrategoLibrary?.
Linearize Expressions
Extend module
IRCanonicalize with transformation rules for linearizing an
IntermediateRepresentation expression and define a strategy to apply the linearization rules.
The result of linearization is a flat list of statements.
Beware for non-termination of
CALL lifting. What is a good strategy?
By first simplifying expressions using simple constant folding rules, better results can
sometimes be obtained. Be aware that no side effects should be removed or reordered by simplification.
Basic Blocks
Divide the list of statements of a
PROC into a list of
basic blocks.
Traces
Reorder the basic blocks into traces.
Make sure that each conditional jump (
CJUMP) is followed by its false label. If necessary rephrase the condition such that this is the case.
Call Space
After canonicalization compute the call space, i.e., the maximum number of arguments of any function called (directly) within the body of a function. This number is needed to compute the size of the
stack frame. The number should be stored in the
CALL parameter of the
PROC fragment of the function. (Use collect
Format Checker
In order to check the result of canonicalization, define a
FormatChecker (using
RecursivePattern) that describes
intermediate representation expressions in canonical form in module
CIRFormat.