;; AMD K6/K6-2 Scheduling
-;; Copyright (C) 2002 ;; Free Software Foundation, Inc.
+;; Copyright (C) 2002, 2004
+;; Free Software Foundation, Inc.
;;
;; This file is part of GCC.
;;
;; You should have received a copy of the GNU General Public License
;; along with GCC; see the file COPYING. If not, write to
;; the Free Software Foundation, 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA. */
+;; Boston, MA 02111-1307, USA.
;;
-;; The K6 has similar architecture to PPro. Important difference is, that
-;; there are only two decoders and they seems to be much slower than execution
-;; units. So we have to pay much more attention to proper decoding for
-;; schedulers. We share most of scheduler code for PPro in i386.c
+;; The K6 architecture is quite similar to PPro. Important difference is
+;; that there are only two decoders and they seems to be much slower than
+;; any of the execution units. So we have to pay much more attention to
+;; proper scheduling for the decoders.
+;; FIXME: We don't do that right now. A good start would be to sort the
+;; instructions based on length.
;;
-;; The fp unit is not pipelined and do one operation per two cycles including
-;; the FXCH.
+;; This description is based on data from the following documents:
;;
-;; alu describes both ALU units (ALU-X and ALU-Y).
-;; alux describes X alu unit
-;; fpu describes FPU unit
-;; load describes load unit.
-;; branch describes branch unit.
-;; store describes store unit. This unit is not modelled completely and only
-;; used to model lea operation. Otherwise it lie outside of the critical
-;; path.
+;; "AMD-K6 Processor Data Sheet (Preliminary information)"
+;; Advanced Micro Devices, Inc., 1998.
+;;
+;; "AMD-K6 Processor Code Optimization Application Note"
+;; Advanced Micro Devices, Inc., 2000.
+;;
+;; CPU execution units of the K6:
+;;
+;; store describes the Store unit. This unit is not modelled
+;; completely and it is only used to model lea operation.
+;; Otherwise it lies outside of any critical path.
+;; load describes the Load unit
+;; alux describes the Integer X unit
+;; mm describes the Multimedia unit, which shares a pipe
+;; with the Integer X unit. This unit is used for MMX,
+;; which is not implemented for K6.
+;; aluy describes the Integer Y unit
+;; fpu describes the FPU unit
+;; branch describes the Branch unit
+;;
+;; The fp unit is not pipelined, and it can only do one operation per two
+;; cycles, including fxcg.
+;;
+;; Generally this is a very poor description, but at least no worse than
+;; the old description, and a lot easier to extend to something more
+;; reasonable if anyone still cares enough about this architecture in 2004.
;;
;; ??? fxch isn't handled; not an issue until sched3 after reg-stack is real.
-;; The decoder specification is in the PPro section above!
-
-;; Shift instructions and certain arithmetic are issued only to X pipe.
-(define_function_unit "k6_alux" 1 0
- (and (eq_attr "cpu" "k6")
- (eq_attr "type" "ishift,ishift1,rotate,rotate1,alu1,negnot,cld"))
- 1 1)
-
-;; The QI mode arithmetic is issued to X pipe only.
-(define_function_unit "k6_alux" 1 0
- (and (eq_attr "cpu" "k6")
- (and (eq_attr "type" "alu,alu1,negnot,icmp,test,imovx,incdec")
- (eq_attr "mode" "QI")))
- 1 1)
-
-(define_function_unit "k6_alu" 2 0
- (and (eq_attr "cpu" "k6")
- (eq_attr "type" "ishift,ishift1,rotate,rotate1,alu1,negnot,alu,icmp,test,imovx,incdec,setcc,lea"))
- 1 1)
-
-(define_function_unit "k6_alu" 2 0
- (and (eq_attr "cpu" "k6")
- (and (eq_attr "type" "imov")
- (eq_attr "memory" "none")))
- 1 1)
-
-(define_function_unit "k6_branch" 1 0
- (and (eq_attr "cpu" "k6")
- (eq_attr "type" "call,callv,ibr"))
- 1 1)
-
-;; Load unit have two cycle latency, but we take care for it in adjust_cost
-(define_function_unit "k6_load" 1 0
- (and (eq_attr "cpu" "k6")
- (ior (eq_attr "type" "pop,leave")
- (eq_attr "memory" "load,both")))
- 1 1)
-
-(define_function_unit "k6_load" 1 0
- (and (eq_attr "cpu" "k6")
- (and (eq_attr "type" "str")
- (eq_attr "memory" "load,both")))
- 10 10)
-
-;; Lea have two instructions, so latency is probably 2
-(define_function_unit "k6_store" 1 0
- (and (eq_attr "cpu" "k6")
- (eq_attr "type" "lea"))
- 2 1)
-
-(define_function_unit "k6_store" 1 0
- (and (eq_attr "cpu" "k6")
- (eq_attr "type" "str"))
- 10 10)
-
-(define_function_unit "k6_store" 1 0
- (and (eq_attr "cpu" "k6")
- (ior (eq_attr "type" "push")
- (eq_attr "memory" "store,both")))
- 1 1)
-
-(define_function_unit "k6_fpu" 1 1
- (and (eq_attr "cpu" "k6")
- (eq_attr "type" "fop,fmov,fcmp,fistp"))
- 2 2)
-
-(define_function_unit "k6_fpu" 1 1
- (and (eq_attr "cpu" "k6")
- (eq_attr "type" "fmul"))
- 2 2)
-
-;; ??? Guess
-(define_function_unit "k6_fpu" 1 1
- (and (eq_attr "cpu" "k6")
- (eq_attr "type" "fdiv,fpspc"))
- 56 56)
-
-(define_function_unit "k6_alu" 2 0
- (and (eq_attr "cpu" "k6")
- (eq_attr "type" "imul"))
- 2 2)
-
-(define_function_unit "k6_alux" 1 0
- (and (eq_attr "cpu" "k6")
- (eq_attr "type" "imul"))
- 2 2)
-
-;; ??? Guess
-(define_function_unit "k6_alu" 2 0
- (and (eq_attr "cpu" "k6")
- (eq_attr "type" "idiv"))
- 17 17)
-
-(define_function_unit "k6_alux" 1 0
- (and (eq_attr "cpu" "k6")
- (eq_attr "type" "idiv"))
- 17 17)
+(define_automaton "k6_decoder,k6_load_unit,k6_store_unit,k6_integer_units,k6_fpu_unit,k6_branch_unit")
+
+;; The K6 instruction decoding begins before the on-chip instruction cache is
+;; filled. Depending on the length of the instruction, two simple instructions
+;; can be decoded in two parallel short decoders, or one complex instruction can
+;; be decoded in either the long or the vector decoder. For all practical
+;; purposes, the long and vector decoder can be modelled as one decoder.
+(define_cpu_unit "k6_decode_short0" "k6_decoder")
+(define_cpu_unit "k6_decode_short1" "k6_decoder")
+(define_cpu_unit "k6_decode_long" "k6_decoder")
+(exclusion_set "k6_decode_long" "k6_decode_short0,k6_decode_short1")
+(define_reservation "k6_decode_short" "k6_decode_short0|k6_decode_short1")
+(define_reservation "k6_decode_vector" "k6_decode_long")
+
+(define_cpu_unit "k6_store" "k6_store_unit")
+(define_cpu_unit "k6_load" "k6_load_unit")
+(define_cpu_unit "k6_alux,k6_aluy" "k6_integer_units")
+(define_cpu_unit "k6_fpu" "k6_fpu_unit")
+(define_cpu_unit "k6_branch" "k6_branch_unit")
+
+;; Shift instructions and certain arithmetic are issued only on Integer X.
+(define_insn_reservation "k6_alux_only" 1
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "ishift,ishift1,rotate,rotate1,alu1,negnot,cld")
+ (eq_attr "memory" "none")))
+ "k6_decode_short,k6_alux")
+
+(define_insn_reservation "k6_alux_only_load" 3
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "ishift,ishift1,rotate,rotate1,alu1,negnot,cld")
+ (eq_attr "memory" "load")))
+ "k6_decode_short,k6_load,k6_alux")
+
+(define_insn_reservation "k6_alux_only_store" 3
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "ishift,ishift1,rotate,rotate1,alu1,negnot,cld")
+ (eq_attr "memory" "store,both,unknown")))
+ "k6_decode_long,k6_load,k6_alux,k6_store")
+
+;; Integer divide and multiply can only be issued on Integer X, too.
+(define_insn_reservation "k6_alu_imul" 2
+ (and (eq_attr "cpu" "k6")
+ (eq_attr "type" "imul"))
+ "k6_decode_vector,k6_alux*3")
+
+(define_insn_reservation "k6_alu_imul_load" 4
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "imul")
+ (eq_attr "memory" "load")))
+ "k6_decode_vector,k6_load,k6_alux*3")
+
+(define_insn_reservation "k6_alu_imul_store" 4
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "imul")
+ (eq_attr "memory" "store,both,unknown")))
+ "k6_decode_vector,k6_load,k6_alux*3,k6_store")
+
+;; ??? Guessed latencies based on the old pipeline description.
+(define_insn_reservation "k6_alu_idiv" 17
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "idiv")
+ (eq_attr "memory" "none")))
+ "k6_decode_vector,k6_alux*17")
+
+(define_insn_reservation "k6_alu_idiv_mem" 19
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "idiv")
+ (eq_attr "memory" "!none")))
+ "k6_decode_vector,k6_load,k6_alux*17")
+
+;; Basic word and doubleword ALU ops can be issued on both Integer units.
+(define_insn_reservation "k6_alu" 1
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "alu,alu1,negnot,icmp,test,imovx,incdec,setcc")
+ (eq_attr "memory" "none")))
+ "k6_decode_short,k6_alux|k6_aluy")
+
+(define_insn_reservation "k6_alu_load" 3
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "alu,alu1,negnot,icmp,test,imovx,incdec,setcc")
+ (eq_attr "memory" "load")))
+ "k6_decode_short,k6_load,k6_alux|k6_aluy")
+
+(define_insn_reservation "k6_alu_store" 3
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "alu,alu1,negnot,icmp,test,imovx,incdec,setcc")
+ (eq_attr "memory" "store,both,unknown")))
+ "k6_decode_long,k6_load,k6_alux|k6_aluy,k6_store")
+
+;; A "load immediate" operation does not require execution at all,
+;; it is available immediately after decoding. Special-case this.
+(define_insn_reservation "k6_alu_imov" 1
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "imov")
+ (and (eq_attr "memory" "none")
+ (match_operand 1 "nonimmediate_operand"))))
+ "k6_decode_short,k6_alux|k6_aluy")
+
+(define_insn_reservation "k6_alu_imov_imm" 0
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "imov")
+ (and (eq_attr "memory" "none")
+ (match_operand 1 "immediate_operand"))))
+ "k6_decode_short")
+
+(define_insn_reservation "k6_alu_imov_load" 2
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "imov")
+ (eq_attr "memory" "load")))
+ "k6_decode_short,k6_load")
+
+(define_insn_reservation "k6_alu_imov_store" 1
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "imov")
+ (eq_attr "memory" "store")))
+ "k6_decode_short,k6_store")
+
+(define_insn_reservation "k6_alu_imov_both" 2
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "imov")
+ (eq_attr "memory" "both,unknown")))
+ "k6_decode_long,k6_load,k6_alux|k6_aluy")
+
+;; The branch unit.
+(define_insn_reservation "k6_branch_call" 1
+ (and (eq_attr "cpu" "k6")
+ (eq_attr "type" "call,callv"))
+ "k6_decode_vector,k6_branch")
+
+(define_insn_reservation "k6_branch_branch" 1
+ (and (eq_attr "cpu" "k6")
+ (eq_attr "type" "ibr"))
+ "k6_decode_short,k6_branch")
+
+;; The load and units have two pipeline stages. The load latency is
+;; two cycles.
+(define_insn_reservation "k6_load_pop" 3
+ (and (eq_attr "cpu" "k6")
+ (ior (eq_attr "type" "pop")
+ (eq_attr "memory" "load,both")))
+ "k6_decode_short,k6_load")
+
+(define_insn_reservation "k6_load_leave" 5
+ (and (eq_attr "cpu" "k6")
+ (eq_attr "type" "leave"))
+ "k6_decode_long,k6_load,(k6_alux|k6_aluy)*2")
+
+;; ??? From the old pipeline description. Egad!
+;; ??? Apparently we take care of this reservation in adjust_cost.
+(define_insn_reservation "k6_load_str" 10
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "str")
+ (eq_attr "memory" "load,both")))
+ "k6_decode_vector,k6_load*10")
+
+;; The store unit handles lea and push. It is otherwise unmodelled.
+(define_insn_reservation "k6_store_lea" 2
+ (and (eq_attr "cpu" "k6")
+ (eq_attr "type" "lea"))
+ "k6_decode_short,k6_store,k6_alux|k6_aluy")
+
+(define_insn_reservation "k6_store_push" 2
+ (and (eq_attr "cpu" "k6")
+ (ior (eq_attr "type" "push")
+ (eq_attr "memory" "store,both")))
+ "k6_decode_short,k6_store")
+
+(define_insn_reservation "k6_store_str" 10
+ (and (eq_attr "cpu" "k6")
+ (eq_attr "type" "str"))
+ "k6_store*10")
+
+;; Most FPU instructions have latency 2 and throughput 2.
+(define_insn_reservation "k6_fpu" 2
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "fop,fmov,fcmp,fistp")
+ (eq_attr "memory" "none")))
+ "k6_decode_vector,k6_fpu*2")
+
+(define_insn_reservation "k6_fpu_load" 6
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "fop,fmov,fcmp,fistp")
+ (eq_attr "memory" "load,both")))
+ "k6_decode_short,k6_load,k6_fpu*2")
+
+(define_insn_reservation "k6_fpu_store" 6
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "fop,fmov,fcmp,fistp")
+ (eq_attr "memory" "store")))
+ "k6_decode_short,k6_store,k6_fpu*2")
+
+(define_insn_reservation "k6_fpu_fmul" 2
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "fmul")
+ (eq_attr "memory" "none")))
+ "k6_decode_short,k6_fpu*2")
+
+(define_insn_reservation "k6_fpu_fmul_load" 2
+ (and (eq_attr "cpu" "k6")
+ (and (eq_attr "type" "fmul")
+ (eq_attr "memory" "load,both")))
+ "k6_decode_short,k6_load,k6_fpu*2")
+
+;; ??? Guessed latencies from the old pipeline description.
+(define_insn_reservation "k6_fpu_expensive" 56
+ (and (eq_attr "cpu" "k6")
+ (eq_attr "type" "fdiv,fpspc"))
+ "k6_decode_short,k6_fpu*56")
+
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