expr.h

gcc库的原代码,对编程有很大帮助.

extern optab udivmod_optab;
extern optab smod_optab;	/* Signed remainder */
extern optab umod_optab;
extern optab flodiv_optab;	/* Optab for floating divide. */
extern optab ftrunc_optab;	/* Convert float to integer in float fmt */
extern optab and_optab;		/* Logical and */
extern optab ior_optab;		/* Logical or */
extern optab xor_optab;		/* Logical xor */
extern optab ashl_optab;	/* Arithmetic shift left */
extern optab ashr_optab;	/* Arithmetic shift right */
extern optab lshr_optab;	/* Logical shift right */
extern optab rotl_optab;	/* Rotate left */
extern optab rotr_optab;	/* Rotate right */
extern optab smin_optab;	/* Signed and floating-point minimum value */
extern optab smax_optab;	/* Signed and floating-point maximum value */
extern optab umin_optab;	/* Unsigned minimum value */
extern optab umax_optab;	/* Unsigned maximum value */

extern optab mov_optab;		/* Move instruction.  */
extern optab movstrict_optab;	/* Move, preserving high part of register.  */

extern optab cmp_optab;		/* Compare insn; two operands.  */
extern optab tst_optab;		/* tst insn; compare one operand against 0 */

/* Unary operations */
extern optab neg_optab;		/* Negation */
extern optab abs_optab;		/* Abs value */
extern optab one_cmpl_optab;	/* Bitwise not */
extern optab ffs_optab;		/* Find first bit set */
extern optab sqrt_optab;	/* Square root */
extern optab sin_optab;		/* Sine */
extern optab cos_optab;		/* Cosine */
extern optab strlen_optab;	/* String length */

/* Tables of patterns for extending one integer mode to another.  */
extern enum insn_code extendtab[MAX_MACHINE_MODE][MAX_MACHINE_MODE][2];

/* Tables of patterns for converting between fixed and floating point. */
extern enum insn_code fixtab[NUM_MACHINE_MODES][NUM_MACHINE_MODES][2];
extern enum insn_code fixtrunctab[NUM_MACHINE_MODES][NUM_MACHINE_MODES][2];
extern enum insn_code floattab[NUM_MACHINE_MODES][NUM_MACHINE_MODES][2];

/* Contains the optab used for each rtx code.  */
extern optab code_to_optab[NUM_RTX_CODE + 1];

/* Passed to expand_binop and expand_unop to say which options to try to use
   if the requested operation can't be open-coded on the requisite mode.
   Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using a library call.
   Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try using a wider mode.
   OPTAB_MUST_WIDEN says try widening and don't try anything else.  */

enum optab_methods
{
  OPTAB_DIRECT,
  OPTAB_LIB,
  OPTAB_WIDEN,
  OPTAB_LIB_WIDEN,
  OPTAB_MUST_WIDEN
};

/* SYMBOL_REF rtx's for the library functions that are called
   implicitly and not via optabs.  */

extern rtx extendsfdf2_libfunc;
extern rtx extendsfxf2_libfunc;
extern rtx extendsftf2_libfunc;
extern rtx extenddfxf2_libfunc;
extern rtx extenddftf2_libfunc;

extern rtx truncdfsf2_libfunc;
extern rtx truncxfsf2_libfunc;
extern rtx trunctfsf2_libfunc;
extern rtx truncxfdf2_libfunc;
extern rtx trunctfdf2_libfunc;

extern rtx memcpy_libfunc;
extern rtx bcopy_libfunc;
extern rtx memcmp_libfunc;
extern rtx bcmp_libfunc;
extern rtx memset_libfunc;
extern rtx bzero_libfunc;

extern rtx eqhf2_libfunc;
extern rtx nehf2_libfunc;
extern rtx gthf2_libfunc;
extern rtx gehf2_libfunc;
extern rtx lthf2_libfunc;
extern rtx lehf2_libfunc;

extern rtx eqsf2_libfunc;
extern rtx nesf2_libfunc;
extern rtx gtsf2_libfunc;
extern rtx gesf2_libfunc;
extern rtx ltsf2_libfunc;
extern rtx lesf2_libfunc;

extern rtx eqdf2_libfunc;
extern rtx nedf2_libfunc;
extern rtx gtdf2_libfunc;
extern rtx gedf2_libfunc;
extern rtx ltdf2_libfunc;
extern rtx ledf2_libfunc;

extern rtx eqxf2_libfunc;
extern rtx nexf2_libfunc;
extern rtx gtxf2_libfunc;
extern rtx gexf2_libfunc;
extern rtx ltxf2_libfunc;
extern rtx lexf2_libfunc;

extern rtx eqtf2_libfunc;
extern rtx netf2_libfunc;
extern rtx gttf2_libfunc;
extern rtx getf2_libfunc;
extern rtx lttf2_libfunc;
extern rtx letf2_libfunc;

extern rtx floatsisf_libfunc;
extern rtx floatdisf_libfunc;
extern rtx floattisf_libfunc;

extern rtx floatsidf_libfunc;
extern rtx floatdidf_libfunc;
extern rtx floattidf_libfunc;

extern rtx floatsixf_libfunc;
extern rtx floatdixf_libfunc;
extern rtx floattixf_libfunc;

extern rtx floatsitf_libfunc;
extern rtx floatditf_libfunc;
extern rtx floattitf_libfunc;

extern rtx fixsfsi_libfunc;
extern rtx fixsfdi_libfunc;
extern rtx fixsfti_libfunc;

extern rtx fixdfsi_libfunc;
extern rtx fixdfdi_libfunc;
extern rtx fixdfti_libfunc;

extern rtx fixxfsi_libfunc;
extern rtx fixxfdi_libfunc;
extern rtx fixxfti_libfunc;

extern rtx fixtfsi_libfunc;
extern rtx fixtfdi_libfunc;
extern rtx fixtfti_libfunc;

extern rtx fixunssfsi_libfunc;
extern rtx fixunssfdi_libfunc;
extern rtx fixunssfti_libfunc;

extern rtx fixunsdfsi_libfunc;
extern rtx fixunsdfdi_libfunc;
extern rtx fixunsdfti_libfunc;

extern rtx fixunsxfsi_libfunc;
extern rtx fixunsxfdi_libfunc;
extern rtx fixunsxfti_libfunc;

extern rtx fixunstfsi_libfunc;
extern rtx fixunstfdi_libfunc;
extern rtx fixunstfti_libfunc;

typedef rtx (*rtxfun) ();

/* Indexed by the rtx-code for a conditional (eg. EQ, LT,...)
   gives the gen_function to make a branch to test that condition.  */

extern rtxfun bcc_gen_fctn[NUM_RTX_CODE];

/* Indexed by the rtx-code for a conditional (eg. EQ, LT,...)
   gives the insn code to make a store-condition insn
   to test that condition.  */

extern enum insn_code setcc_gen_code[NUM_RTX_CODE];

#ifdef HAVE_conditional_move
/* Indexed by the the machine mode, gives the insn code to make a conditional
   move insn.  */

extern enum insn_code movcc_gen_code[NUM_MACHINE_MODES];
#endif

/* This array records the insn_code of insns to perform block moves.  */
extern enum insn_code movstr_optab[NUM_MACHINE_MODES];

/* Define functions given in optabs.c.  */

/* Expand a binary operation given optab and rtx operands.  */
extern rtx expand_binop PROTO((enum machine_mode, optab, rtx, rtx, rtx,
			       int, enum optab_methods));

/* Expand a binary operation with both signed and unsigned forms.  */
extern rtx sign_expand_binop PROTO((enum machine_mode, optab, optab, rtx,
				    rtx, rtx, int, enum optab_methods));

/* Generate code to perform an operation on two operands with two results.  */
extern int expand_twoval_binop PROTO((optab, rtx, rtx, rtx, rtx, int));

/* Expand a unary arithmetic operation given optab rtx operand.  */
extern rtx expand_unop PROTO((enum machine_mode, optab, rtx, rtx, int));

/* Expand the absolute value operation.  */
extern rtx expand_abs PROTO((enum machine_mode, rtx, rtx, int, int));

/* Expand the complex absolute value operation.  */
extern rtx expand_complex_abs PROTO((enum machine_mode, rtx, rtx, int));

/* Generate an instruction with a given INSN_CODE with an output and
   an input.  */
extern void emit_unop_insn PROTO((int, rtx, rtx, enum rtx_code));

/* Emit code to perform a series of operations on a multi-word quantity, one
   word at a time.  */
extern rtx emit_no_conflict_block PROTO((rtx, rtx, rtx, rtx, rtx));

/* Emit code to make a call to a constant function or a library call. */
extern void emit_libcall_block PROTO((rtx, rtx, rtx, rtx));

/* Emit one rtl instruction to store zero in specified rtx.  */
extern void emit_clr_insn PROTO((rtx));

/* Emit one rtl insn to store 1 in specified rtx assuming it contains 0.  */
extern void emit_0_to_1_insn PROTO((rtx));

/* Emit one rtl insn to compare two rtx's.  */
extern void emit_cmp_insn PROTO((rtx, rtx, enum rtx_code, rtx,
				 enum machine_mode, int, int));

/* Nonzero if a compare of mode MODE can be done straightforwardly
   (without splitting it into pieces).  */
extern int can_compare_p PROTO((enum machine_mode));

/* Emit a library call comparison between floating point X and Y.
   COMPARISON is the rtl operator to compare with (EQ, NE, GT, etc.).  */
extern void emit_float_lib_cmp PROTO((rtx, rtx, enum rtx_code));

/* Generate code to indirectly jump to a location given in the rtx LOC.  */
extern void emit_indirect_jump PROTO((rtx));

#ifdef HAVE_conditional_move
/* Emit a conditional move operation.  */
rtx emit_conditional_move PROTO((rtx, enum rtx_code, rtx, rtx,
				 enum machine_mode, rtx, rtx,
				 enum machine_mode, int));

/* Return non-zero if the conditional move is supported.  */
int can_conditionally_move_p PROTO((enum machine_mode mode));
#endif

/* Create but don't emit one rtl instruction to add one rtx into another.
   Modes must match; operands must meet the operation's predicates.
   Likewise for subtraction and for just copying.
   These do not call protect_from_queue; caller must do so.  */
extern rtx gen_add2_insn PROTO((rtx, rtx));
extern rtx gen_sub2_insn PROTO((rtx, rtx));
extern rtx gen_move_insn PROTO((rtx, rtx));
extern int have_add2_insn PROTO((enum machine_mode));
extern int have_sub2_insn PROTO((enum machine_mode));

/* Return the INSN_CODE to use for an extend operation.  */
extern enum insn_code can_extend_p PROTO((enum machine_mode,
					  enum machine_mode, int));

/* Generate the body of an insn to extend Y (with mode MFROM)
   into X (with mode MTO).  Do zero-extension if UNSIGNEDP is nonzero.  */
extern rtx gen_extend_insn PROTO((rtx, rtx, enum machine_mode,
				  enum machine_mode, int));

/* Initialize the tables that control conversion between fixed and
   floating values.  */
extern void init_fixtab PROTO((void));
extern void init_floattab PROTO((void));

/* Generate code for a FLOAT_EXPR.  */
extern void expand_float PROTO((rtx, rtx, int));

/* Generate code for a FIX_EXPR.  */
extern void expand_fix PROTO((rtx, rtx, int));

/* Call this once to initialize the contents of the optabs
   appropriately for the current target machine.  */
extern void init_optabs	PROTO((void));