* emit-rtl.c (global_rtl): Update comment.
	(const_double_htab, const_double_htab_hash,
	const_double_htab_hash, lookup_const_double): New.
	(const_int_htab_hash, const_int_htab_eq): Remove const
	qualifiers, which cause tons of warnings with RTL checking on.
	(gen_rtx_CONST_DOUBLE): Deleted.
	(const_double_from_real_value): New function - bears some
	resemblance to the former immed_real_const_1.
	(immed_double_const): Moved here from varasm.c and
	simplified.
	(gen_rtx_REG): Make REGNO unsigned to squelch warnings.
	(gen_rtx_SUBREG): Use gen_rtx_raw_SUBREG.
	(gen_rtx): Use immed_double_const.
	(init_emit_once): Initialize the const_double_htab.  Use
	REAL_VALUE_FROM_INT where possible.  Can now use
	CONST_DOUBLE_FROM_REAL_VALUE when setting up const_tiny_rtx.
	* varasm.c (struct varasm_status): Remove x_const_double_chain.
	(const_double_chain, immed_real_const, clear_const_double_mem): Delete.
	(immed_double_const, immed_real_const_1): Moved to emit-rtl.c.
	(init_varasm_status, mark_varasm_status): Don't touch
	x_const_double_chain.

	* output.h: Delete prototype for clear_const_double_mem.
	* real.h: Make REAL_VALUE_TYPE a macro again.  Remove leading
	'0' slot from all CONST_DOUBLE_FORMAT definitions.  Prototype
	const_double_from_real_value, not immed_real_const_1, and use
	it to define CONST_DOUBLE_FROM_REAL_VALUE.  Define new macro
	CONST_DOUBLE_ATOF.
	* rtl.h (CONST_DOUBLE_CHAIN): Kill.
	(CONST_DOUBLE_LOW, CONST_DOUBLE_HIGH): Adjust.
	(gen_rtx_CONST_DOUBLE, immed_real_const): Delete prototypes.
	(gen_rtx_REG): Second arg is unsigned.

	* gengenrtl.c (special_rtx): Take out CONST_DOUBLE.
	(excluded_rtx): New, return true for CONST_DOUBLE.
	(genmacro): Write nothing for excluded codes.
	* combine.c (combine_simplify_rtx): Use CONST_DOUBLE_FROM_REAL_VALUE.
	* expr.c (expand_expr): Likewise.
	* ggc-common.c (ggc_mark_rtx_children_1): Don't mark the
	CONST_DOUBLE_CHAIN.
	* toplev.c (rest_of_compilation): Don't call
	clear_const_double_mem.

	* config/rs6000/rs6000.c (rs6000_float_const): Delete.
	(rs6000_hash_constant): Remove CONST_DOUBLE special case.
	(toc_hash_eq): Remove CONST_DOUBLE and LABEL_REF special cases.
	* config/rs6000/rs6000-protos.h: Don't prototype rs6000_float_const.
	* config/c4x/c4x.md, config/rs6000/rs6000.md: Use CONST_DOUBLE_ATOF.
	* config/dsp16xx/dsp16xx.md, config/mips/mips.md,
	config/pa/pa.md: Use CONST_DOUBLE_FROM_REAL_VALUE.
	* config/sparc/sparc.md, config/sparc/sparc.c: Use immed_double_const.

From-SVN: r53409