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Document the forwardrefmax pragma Since the forwardrefmax is useful for combatting huge assembly times in many sources, actually document it so people can find it.
author William Astle <lost@l-w.ca>
date Thu, 09 Apr 2015 12:51:02 -0600
parents 507f442dc71e
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346:9e35f7a1fca1 347:330a66a0f45a
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338 a symbol.</P 338 a symbol.</P
339 ><P 339 ><P
340 >It is important to note that if a symbol is defined but it does not 340 >It is important to note that if a symbol is defined but it does not
341 yet evaluate to a constant value at the point where the conditional appears, 341 yet evaluate to a constant value at the point where the conditional appears,
342 the assembler will still complain about a non constant condition.</P 342 the assembler will still complain about a non constant condition.</P
343 ></DD
344 ><DT
345 >forwardrefmax</DT
346 ><DD
347 ><P
348 >This pragma will disable forward reference optimization completely.
349 Ordinarily, LWASM will attempt to select the shortest possible addressing
350 mode for forward references. However, in many source files, especially
351 those not using the PCR relative addressing modes, this optimization is
352 pointless since the assembler will almost certainly settle on a 16 bit
353 offset or address. If all variables in the direct page are defined before
354 the main body of the code, the benefit of forward reference optimization
355 almost certainly vanishes completely. However, the cost of doing that
356 optimization remains and can result in a very long assembly time.</P
357 ><P
358 >Enabling this pragma will cause all forward references to use the
359 maximum offset or address size, much the same has EDTASM and other pure
360 two pass assemblers do. The side effect is that all line lengths and
361 symbol values are fully resolved after the initial parsing pass and the
362 amount of work to resolve everything becomes almost nil.</P
363 ><P
364 >While this pragma can be applied selectively to sections of source
365 code (use *PRAGMA if doing so and compatibility with other assemblers
366 is desired), it is likely more useful when provided as a command line
367 pragma.</P
368 ><P
369 >It should be noted that the presence or absence of this pragma
370 will not change the correctness of the generated code unless cycle counts
371 or byte counts are critical (which they usually are not). It also will
372 not override the operand size override prefixes (&lt; and &gt;). It only
373 applies when the assembler is left to guess what the operand size is.</P
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347 >As a convenience, each input file has a pragma state stack. This 378 >As a convenience, each input file has a pragma state stack. This
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