Tidy up the shift methods on the macro-assembler interface.
Patch by Gavin Barraclough <[email protected]> on 2009-11-06
Reviewed by Oliver Hunt.
Currently behaviour of shifts of a magnitude > 0x1f is undefined.
Instead defined that all shifts are masked to this range. This makes a lot of
practical sense, both since having undefined behaviour is not particularly
desirable, and because this behaviour is commonly required (particularly since
it is required bt ECMA-262 for shifts).
Update the ARM assemblers to provide this behaviour. Remove (now) redundant
masks from JITArithmetic, and remove rshiftPtr (this was used in case that
could be rewritten in a simpler form using rshift32, only optimized JSVALUE32
on x86-64, which uses JSVALUE64!)
- assembler/MacroAssembler.h:
- assembler/MacroAssemblerARM.h:
(JSC::MacroAssemblerARM::lshift32):
(JSC::MacroAssemblerARM::rshift32):
- assembler/MacroAssemblerARMv7.h:
(JSC::MacroAssemblerARMv7::lshift32):
(JSC::MacroAssemblerARMv7::rshift32):
- assembler/MacroAssemblerX86_64.h:
- jit/JITArithmetic.cpp:
(JSC::JIT::emit_op_lshift):
(JSC::JIT::emit_op_rshift):
