[PATCH] - Use of powerpc 64bit instructions in 32bit ABI

[Fariborz Jahanian <fjahanian at apple dot com>]

We would like to support use of powerPC's 64bit instructions in Macho-O 
powerPC's 32bit abi. This is performance gain
for programs which make heavy use of 'long long' data types. 186.crafty 
has shown good performance gain on the G5
machine. To summarize, the -mpowerpc64 option allows GCC to generate 
the additional 64-bit instructions that are
found in the full PowerPC64 architecture and to treat GPRs as 64-bit, 
doubleword quantities (gcc man page). This patch
makes the necessary changes at point of calls, processing of incoming 
function arguments, function return values and
var-args so 32bit abi does not change. Patch has been tested by 
bootstrapping gcc and running deja-gnu test suite on
powerpc.


ChangeLog entry:

2003-10-14  Fariborz Jahanian  <fjahanian@apple.com>

        * calls.c: emit_push_insn moved from expr.c and made static.
        (load_register_parameters): use of UNITS_PER_REGISTER_ARGUMENT 
macro.
        (store_one_arg): use of UNITS_PER_REGISTER_ARGUMENT macro.
        * doloop.c (doloop_optimize): use mode that loop actually 
iterates in,
        instead of word_mode.
        * expmed.c (expand_mult_highpart): widen the mode if narrower 
than
        SImode instead of word_mode.
        * expr.c: move_block_to_reg and move_block_from_reg moved to 
function.c.
        emit_push_insn moved to calls.c. STACK_GROWS_DOWNWARD,
        STACK_PUSH_CODE PRE_INC definitions moved to expr.h. These are 
done to
        make calls.c and function.c self-contained in RTL generation 
for calls and
        function arguments.
        * expr.h: REGISTER_ARGUMENT_MODE, UNITS_PER_REGISTER_ARGUMENT 
and
        REGISTER_ARGUMENT_BITSIZE macro definitions added. 
STACK_GROWS_DOWNWARD,
        STACK_PUSH_CODE PRE_INC definitions moved here and removed from 
expr.c.
        Declaration of move_block_from_reg, move_block_to_reg and 
emit_push_insn
        removed.
        * function.c (gen_subword_offset): new function used for 
generating RTLs
        for save and restore of arguments in registers.
        (operand_subword_offset_force): new function used for 
generating RTLs
        for save and restore of arguments in registers.
        (move_block_from_reg, move_block_to_reg): moved here from expr.c
        (assign_parms): generate rtl to combine arguments passed in two 
registers
        in a register.
        * function.h: added declaration of move_block_from_reg.
        * reload.c (find_equiv_reg): Examine DF const to see if we can 
use
        one subword of the 64-bit value. Reg must be two 32-bit 
registers with DF mode.
        * unroll.c (precondition_loop_p): use mode that loop actually 
iterates in,
        instead of word_mode.
        * rs6000.c (build_mask64_2_operand): this routine is made to 
work for 32bit
        hosted gcc generating 64bit instructions.
        (input_operand): use UNITS_PER_REGISTER_ARGUMENT where 
UNITS_PER_WORD was used.
        (rs6000_emit_set_long_const): fix bug when input arguments are 
64bit long in value.
        (rs6000_emit_move): use REGISTER_ARGUMENT_MODE instead of 
word_mode.
        (init_cumulative_args): add code to know if a call is a vararg 
call.
        (function_arg): splits up a DFmode or DImode argument in vararg 
list into zero,
        one or two GPRs.
        (rs6000_va_start, rs6000_va_arg, rs6000_stack_info,
        rs6000_emit_prologue, rs6000_output_function_epilogue): misc 
changes to use
        appropriate macros.
        (rs6000_function_value): split DImode return values into two 
psuedo registers.
        * rs6000.h: Definitions of new macros are added here.
        * rs6000.md: Separate TARGET_POWERPC64 patterns for 
TARGET_64BIT or TARGET_32BIT.
        (ashrdi3_to_si_no_power) Generate more efficient code for 
32-bit right-shift of
        a "long long" argument.
        * tm.texi: Three new macros; REGISTER_ARGUMENT_BITSIZE, 
UNITS_PER_REGISTER_ARGUMENT
        and REGISTER_ARGUMENT_MODE are explained here.

Attachment: ppc_fsf3dot4_patch.txt
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