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+ More information and suggestions
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carl
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@ -1,15 +1,16 @@
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$Id$
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History
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-------
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Module CPUBASE
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--------------
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13th oct 1999 remark about alignment added (FK)
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CONSTANTS used throughout the code generator
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--------------------------------------------
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CVS Log see at the end of that file
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frame_pointer contains the register used as frame pointer
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stack_pointer contains the register used as stack pointer
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self_pointer contains the register used as self pointer
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frame_pointer equals the register used as frame pointer
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stack_pointer equals the register used as stack pointer
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self_pointer equals the register used as self pointer
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accumulator equals the register which will be used
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as function return values
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unusedregsint set of Currently available integer registers
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@ -34,6 +35,30 @@ mmregs all!! available multimedia register
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lvaluelocations a set of all locations which can be an l-value
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Locations
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---------
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The first pass assigns these location types which are then
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used by the code generator to write out the correct instructions:
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LOC_INVALID = This is an error and should never occur
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LOC_REGISTER = Location is in a register
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LOC_MEM = Memory reference (symbolic or register address?)
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LOC_REFERENCE = Memory reference (symbolic or register address?)
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LOC_JUMP = ????
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LOC_FLAGS = Value is in the flags (Florian, this will give problems!)
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LOC_CREGISTER = Value is in a constant register (across calls -
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used for optimizations) - Constant registers
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should not be directly modified????
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LOC_CONST = Value is a numeric constant
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Operand Sizes
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-------------
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OS_NO = No operand size.
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OS_8 = 8-bit signed or unsigned value
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OS_16 = 16-bit signed or unsigned value
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OS_32 = 32-bit signed or unsigned value
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OS_64 = 64-bit signed or unsigned value
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Intel specific
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--------------
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unusedregssse
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@ -78,12 +103,13 @@ The code generation can be seperated into 3 layers:
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3. the code generator object
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1.: This procedure does very high level stuff, if the code generation
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is processor independed, it calls the appropriate procedures of the
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is processor independent, it calls the appropriate procedures of the
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code generator object to generate the code, but in most cases, it
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calls procedure variables of the second layer
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2. This procedure variables must be initialized to match to the match the
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current processor
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2. This procedure variables must be initialized to match the
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current processor, these variables are used to optimize
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existing processor instructions(? CEC).
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The following procedure variables are currently used
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@ -94,7 +120,8 @@ p2_assignment_int64_reg Do an assignment of a int64
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3. The code generator object does very basic operations like generating
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move code etc.
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move code etc, which is called by the p2_ functions and by the
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secondpass procedures.
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Alignment
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---------
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@ -105,12 +132,196 @@ values: 1,2,4,8,16 (1 means unligned). The code generator must update
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that field at the appropriate places and take care of it when
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generating the code
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MODULE CGOBJ (The code generator object)
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------------
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This is the basis of the code generator, it includes several
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template instructions which are used to create a processor
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independant code generator.
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Fields:
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scratch_register_array_pointer : aword;
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?????????????????????
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Indicates the free scratch registers?
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unusedscratchregisters : tregisterset;
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This holds the currently unused registers which can
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be used as temporary placeholders.
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alignment : talignment; ?? Why is this in cg object, should not
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this be a constant instead?
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Template instructions
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---------------------
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procedure a_call_name
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Call a routine by symbolic name with a possible
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numeric offset value.
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???? WE ASSUME UNSIGNED???
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{ move instructions }
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procedure a_load_const_reg
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--------------------------
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Move a constant value to a register
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procedure a_load_reg_ref
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------------------------
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Move a register value to a memory reference
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procedure a_load_ref_reg
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------------------------
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Move the value at a specified address into a register
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procedure a_load_reg_reg
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------------------------
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Move from register to register
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WE NEED !!!!MOVE WITH SIGN EXTENSION??????????????????????
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{ comparison operations }
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????????????? WHAT DOES THE LABELS MEAN????????
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procedure a_cmp_reg_const_label(list : paasmoutput;size : tcgsize;cmp_op : topcmp;a : aword;reg : tregister;
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l : pasmlabel);virtual;
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procedure a_cmp_reg_reg_label(list : paasmoutput;size : tcgsize;cmp_op : topcmp;reg1,reg2 : tregister;l : pasmlabel);
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procedure a_cmp_reg_ref_label(list : paasmoutput;size : tcgsize;cmp_op : topcmp;reg : tregister;l : pasmlabel);
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procedure a_cmp_ref_const_label(list : paasmoutput;size : tcgsize;cmp_op : topcmp;a : aword;reg : tregister;
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l : pasmlabel);
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procedure a_jmp_cond(list : paasmoutput;cond : TOpCmp;l: pasmlabel);
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procedure a_loadaddress_ref_reg(list : paasmoutput;const ref : treference;r : tregister);virtual;
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??????????????
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{ allocates register r by inserting a pai_realloc record }
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procedure a_reg_alloc(list : paasmoutput;r : tregister);
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{ deallocates register r by inserting a pa_regdealloc record}
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procedure a_reg_dealloc(list : paasmoutput;r : tregister);
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{ returns a register for use as scratch register }
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function get_scratch_reg(list : paasmoutput) : tregister;
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{ releases a scratch register }
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procedure free_scratch_reg(list : paasmoutput;r : tregister);
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{************************************************}
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{ code generation for subroutine entry/exit code }
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{ initilizes data of type t }
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{ if is_already_ref is true then the routines assumes }
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{ that r points to the data to initialize ???? }
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procedure g_initialize(list : paasmoutput;t : pdef;const ref : treference;is_already_ref : boolean);
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{ finalizes data of type t }
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{ if is_already_ref is true then the routines assumes }
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{ that r points to the data to finalizes ???? }
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procedure g_finalize(list : paasmoutput;t : pdef;const ref : treference;is_already_ref : boolean);
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{ helper routines }
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procedure g_initialize_data(list : paasmoutput;p : psym);
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procedure g_incr_data(list : paasmoutput;p : psym);
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procedure g_finalize_data(list : paasmoutput;p : pnamedindexobject);
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procedure g_copyvalueparas(list : paasmoutput;p : pnamedindexobject);
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procedure g_finalizetempansistrings(list : paasmoutput);
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procedure g_entrycode(list : paasmoutput;
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const proc_names : tstringcontainer;make_global : boolean;
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stackframe : longint;var parasize : longint;
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var nostackframe : boolean;inlined : boolean);
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procedure g_exitcode(list : paasmoutput;parasize : longint;
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nostackframe,inlined : boolean);
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{ string helper routines }
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procedure g_decrstrref(list : paasmoutput;const ref : treference;t : pdef);
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procedure g_removetemps(list : paasmoutput;p : plinkedlist);
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{ passing parameters, per default the parameter is pushed }
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{ nr gives the number of the parameter (enumerated from }
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{ left to right), this allows to move the parameter to }
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{ register, if the cpu supports register calling }
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{ conventions }
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procedure a_param_reg(list : paasmoutput;size : tcgsize;r : tregister;nr : longint);virtual;
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procedure a_param_const(list : paasmoutput;size : tcgsize;a : aword;nr : longint);virtual;
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procedure a_param_ref(list : paasmoutput;size : tcgsize;const r : treference;nr : longint);virtual;
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procedure a_paramaddr_ref(list : paasmoutput;const r : treference;nr : longint);virtual;
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{**********************************}
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{ these methods must be overriden: }
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{ Remarks:
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* If a method specifies a size you have only to take care
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of that number of bits, i.e. load_const_reg with OP_8 must
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only load the lower 8 bit of the specified register
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the rest of the register can be undefined
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if necessary the compiler will call a method
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to zero or sign extend the register
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* The a_load_XX_XX with OP_64 needn't to be
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implemented for 32 bit
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processors, the code generator takes care of that
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* the addr size is for work with the natural pointer
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size
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* the procedures without fpu/mm are only for integer usage
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* normally the first location is the source and the
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second the destination
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}
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Virtual instruction templates:
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procedure g_stackframe_entry(list : paasmoutput;localsize : longint);virtual;
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{ restores the frame pointer at procedure exit, for the }
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{ i386 it generates a simple leave }
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procedure g_restore_frame_pointer(list : paasmoutput);virtual;
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{ some processors like the PPC doesn't allow to change the stack in }
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{ a procedure, so we need to maintain an extra stack for the }
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{ result values of setjmp in exception code }
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{ this two procedures are for pushing an exception value, }
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{ they can use the scratch registers }
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procedure g_push_exception_value_reg(list : paasmoutput;reg : tregister);virtual;
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procedure g_push_exception_value_const(list : paasmoutput;reg : tregister);virtual;
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{ that procedure pops a exception value }
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procedure g_pop_exception_value_reg(list : paasmoutput;reg : tregister);virtual;
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procedure g_return_from_proc(list : paasmoutput;parasize : aword);virtual;
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{********************************************************}
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{ these methods can be overriden for extra functionality }
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{ the following methods do nothing: }
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procedure g_interrupt_stackframe_entry(list : paasmoutput);virtual;
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procedure g_interrupt_stackframe_exit(list : paasmoutput);virtual;
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procedure g_profilecode(list : paasmoutput);virtual;
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procedure g_stackcheck(list : paasmoutput;stackframesize : longint);virtual;
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procedure a_load_const_ref(list : paasmoutput;size : tcgsize;a : aword;const ref : treference);virtual;
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procedure g_maybe_loadself(list : paasmoutput);virtual;
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{ copies len bytes from the source to destination, if }
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{ loadref is true, it assumes that it first must load }
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{ the source address from the memory location where }
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{ source points to }
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procedure g_concatcopy(list : paasmoutput;const source,dest : treference;len : aword;loadref : boolean);virtual;
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{ uses the addr of ref as param, was emitpushreferenceaddr }
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procedure a_param_ref_addr(list : paasmoutput;r : treference;nr : longint);virtual;
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CVS Log
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-------
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$Log$
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Revision 1.5 2000-03-01 15:36:12 florian
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Revision 1.6 2000-03-02 03:22:16 carl
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+ More information and suggestions
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Revision 1.5 2000/03/01 15:36:12 florian
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* some new stuff for the new cg
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Revision 1.4 1999/10/14 14:57:54 florian
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