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[PATCH rs6000] Disable some Cell microcoded instructions


Hi,
  The Cell has some instructions which are microcoded and microcoded
instructions have a couple of effects on the performance.  First there
is a 7 cycle bubble to fetch the opcodes from the microcoded ROM and
also the second hardware thread has to be off while these microcoded
instructions are executing.  These two factors together make it
profitable to turn these microcoded instructions into non microcoded
instructions.  This patch does just do that.  It also adds a warning
if the instruction was emitted was a microcoded instruction.

The only remaining microcoded instruction which is not emitted as a
non microcoded instruction is the non immediate shift/rotate
instructions.  Even though they could be, I have not done this yet.
Since that means producing a loop or some jump table method.

OK? Bootstrapped and tested on powerpc64-linux-gnu configured with
--with-tune=cell.

 9 files changed, 335 insertions(+), 139 deletions(-)

This work is based on work done by Grace Cha, Kaushal Kantawala,
Trevor Smigiel and myself.

Thanks,
Andrew Pinski

ChangeLog:
* doc/invoke.texi (-mgen-cell-microcode): Document.
(-mwarn-cell-microcode): Document.
* cfglayout.c (locator_location): Export.
* rtl.h (locator_location): Define prototype.
* config/rs6000/predicates.md (cc_reg_not_micro_cr0_operand): New predicate.
* rs6000/rs6000-protos.h (rs6000_final_prescan_insn): Define prototype.
* config/rs6000/rs6000.opt (mgen-cell-microcode): New option.
(mwarn-cell-microcode): New option.
* rs6000/rs6000.c (rs6000_cell_dont_microcode): Delete unused variable.
(rs6000_override_options): Set rs6000_gen_cell_microcode if tuning for
cell and not already set.
Turn off string instructions if not generating cell microcode.
(rs6000_final_prescan_insn): New function that warns about microcoded
instructions.
* config/rs6000/rs6000.h (FINAL_PRESCAN_INSN): Define.
* config/rs6000/rs6000.md
Replace cc_reg_not_cr0_operand with cc_reg_not_micro_cr0_operand if
the instruction would have been microcoded on the Cell.
Set cell_micro to always on unnamed patterns for the string instructions.
(cell_micro): Update definition, remove load/store conditional microcoded.
(sign_extend:DI): Define new pattern for non microcoded version.
(sign_extend:SI): Likewise.
(compare (div:P)): Set cell_micro to not.
(andsi3): Define as an expand.
(andsi3_mc): New pattern.
(andsi3_nomc): New pattern.
(andsi3_internal0_nomc): New pattern.
(andsi3_internal2): Rename to ...
(andsi3_internal2_mc): this and enable iff generating microcode.
(andsi3_internal3): Rename to ...
(andsi3_internal3_mc): this and enable iff generating microcode.
(andsi3_internal4): Enable iif generating microcode.
(andsi3_internal5): Rename to ..
(andsi3_internal5_mc): this and enable iff generating microcode.
(andsi3_internal5_nomc): New pattern.
(extzvdi_internal1): Enable iff generating microcode.
(extzvdi_internal2): Likewise.
(rotlsi3_internal7): Set cell_micro to always if non immediate form.
(anddi3): Change to expand.
(anddi3_mc): Rename from anddi3.
(anddi3_no_mc): New pattern.
(anddi3_internal2): Rename to ..
(anddi3_internal2_mc): this and enable iff generating microcode.
(anddi3_internal2_nomc): New pattern.
(anddi3_internal3): Rename to ..
(anddi3_internal3_mc): this and enable iff generating microcode.
(anddi3_internal3_nomc): New pattern.
(movti_string): Set cell_micro to always if TARGET_STRING.
(stmsi8): Set cell_micro to always.
(stmsi7): Likewise.
(stmsi6): Likewise.
(stmsi5): Likewise.
(stmsi4): Likewise.
(stmsi3): Likewise.
(stmsi8_power): Likewise.
(stmsi7_power): Likewise.
(stmsi6_power): Likewise.
(stmsi5_power): Likewise.
(stmsi4_power): Likewise.
(stmsi3_power): Likewise.
(movsi_update2): Enable iff generating microcode.
(movhi_update3): Likewise.
(lmw): Set cell_micro to always.

Attachment: microcodepatch.diff.txt
Description: Text document


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