This is where the various optimizing switches and their actions are described, grouped per
- with n = 1..4: these switches activate the optimizer. A higher level automatically includes
all lower levels.
- Level 1 (-O1) activates the peephole optimizer (common instruction sequences are
replaced by faster equivalents).
- Level 2 (-O2) enables the assembler data flow analyzer, which allows the common
subexpression elimination procedure to remove unnecessary reloads of registers
with values they already contain.
- Level 3 (-O3) equals level 2 optimizations plus some time-intensive optimizations.
- Level 4 (-O4) equals level 3 optimizations plus some optimizations which may
have side effects.
- Set alignment of X to Y.
- XXX Enable or disable specific optimizations; See section 1.2.58 on 151 for a list
of possible values for XXX.
- Set target cpu for optimizing to XXX; see fpc -i or fpc -ic for possible values.
- Generate whole-program optimization feedback for optimization XXX see fpc -i
or fpc -iw for possible values
- Perform whole-program optimization XXX; see fpc -i or fpc -iw for possible values
- Optimize for size rather than speed.
A more complete description of possible optimization switches can be found in section 1.2.58 on