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Issues in compiling PASC into SPARC assembly. Predefined subroutines. Write them in C

Issues in compiling PASC into SPARC assembly. Predefined subroutines. Write them in C Compile them with GCC or CC Code generation must following the CC calling convention %o0: first argument %o1: second argument See lib.c and t1.s. Memory allocation:

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Issues in compiling PASC into SPARC assembly. Predefined subroutines. Write them in C

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  1. Issues in compiling PASC into SPARC assembly. • Predefined subroutines. • Write them in C • Compile them with GCC or CC • Code generation must following the CC calling convention • %o0: first argument • %o1: second argument • See lib.c and t1.s

  2. Memory allocation: • Global variables: just allocation a chunk of memory • Augment the symbol table to include offsets. • You can associate the symbol with its location. • Still need to use offset to deal with arrays and records. • Accessing the variables: see t2.pasc • Local variables: • Allocate space on the stack. • Access the variable through the frame point (using the offset information)

  3. Memory allocation: • Temporaries: • To simplify the compilation, we can always use memory to store the temporaries. • With the reuse scheme, the number of temporaries would not be too many – can just allocate as a global data • Code generation for calculations • SPARC only performs computations using registers. • Can just generate a sequence of code for each intermediate instruction, such as t1 := t2 + t3 • See example t3.s

  4. Other features of sparc assembly: • Delay slot – the instruction after a branch instruction will be executed. • To simplify code generation, add ‘nop’ to every branch instruction. • save/restore: the use of register files to speed up function calls. • Data alignment: integers must be aligned to 4 bytes.

  5. The use of proj4.c • See example1.c and example2.c • It would help if you implement the generate emit routine.

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