Reference Guide

zend_optimizerplus.optimization_level
API Reference
A bitmask, where each bit enables or disables the appropriate Optimizer+ features (where 0 is disabled
and 1 is enabled).
Type: integer
Default Value: 0xfffffbbf
Available since version 4.0
The following is a list of each bit represented in the value :
bit 0 - Enables/disables optimization step 1:
• CSE - constants subexpressions elimination
• Sequences of ADD_CHAR/ADD_STRING optimization
bit 1 - Enables/disables optimization step 2:
• Convert constant operands to expected types
• Convert conditional jumps with constant operands
• Optimize static BRK and CONT
bit 2 - Enables/disables optimization step 3:
• Convert $a = $a + expr into $a += expr
• Convert $a++ into ++$a
• Optimize series of JMPs
bit 3 - Enables/disables optimization step 4:
• PRINT and ECHO optimization
bit 4 - Enables/disables optimization step 5:
• block optimization (the most expensive optimization pass which perform many different
optimization patterns based on CFG - control flow graph)
bit 8 - Enables/disables optimization step 9:
• register allocation (allows re-usage of temporary variables)
bit 9 - Enables/disables optimization step 10:
• remove NOPs
zend_optimizerplus.enable_slow_optimizations
Enables or disables the optimization passes that may take significant time, based on an internal runtime
calculation
Type: boolean
Default Value: 1
Available since version 4.0
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