Re: HLL syntax & structure suited to rapid compilation?

Steve Horne wrote:
> On 24 Jul 2002 02:22:03 -0400, "gswork" <gswork@mailcity.com> wrote:


> More important, perhaps, is how 'explicit' the grammar is. For
> instance, in C and C++ a parser needs to look at run-time generated
> tables of identifiers to disambiguate many rules.


The tendancy that Pascal compilers are faster is afaik mainly _NOT_ parsing
related. True, Pascal parses easily, but the most important reasons why e.g.
TP/BP is so fast, are
- the unit system with precompiled units, and parsed headers and
- the all in one "make" (dependancy resolver), preprocessor,
    compiler, assembler, linker combination.


I think a C system that caches headers, and compiles programs in one run,
without relying too much on externals, could be sped up significantly too.


Take e.g. GCC, if you run "make" to build a program, it invokes:
- Make
- maybe some small shellutils/commands in the makefile
- compiler which invokes
- the preprocessor
- then compiles the sources and pipes the resulting assembler to the assembler.
- (AR to build libraries of part of the system)
- LD to finish linking it.


True, the amount of work required to implement a equivalent compiler for C
is probably higher than for Pascal, (the same goes for the optimizer) but if
the work is done, it shouldn't be that much slower.
[Turbo C started from Wizard C, a competent but not particularly fast
C compiler, added pretty much exactly the performance tweaks suggested
above, and became really fast. -John]

Return to the comp.compilers page.
Search the comp.compilers archives again.