diff options
author | wilson <wilson@138bc75d-0d04-0410-961f-82ee72b054a4> | 2004-04-21 23:21:59 +0000 |
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committer | wilson <wilson@138bc75d-0d04-0410-961f-82ee72b054a4> | 2004-04-21 23:21:59 +0000 |
commit | b462e7568ee276323f5896929fa8923cda71e6bf (patch) | |
tree | 5cf9396ca05bbcaf40749be722dbfd67a385d142 /gcc/config/mips/sb1.md | |
parent | 46978c1cdab19014ba82252d65a0aae64506aa40 (diff) | |
download | gcc-b462e7568ee276323f5896929fa8923cda71e6bf.tar.gz |
MIPS SB-1 DFA scheduler.
* config/mips/mips-protos.h (fp_register_operand, lo_operand): Declare.
* config/mips/mips.c (mips_multipass_dfa_lookahead): Declare.
(TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD): New.
(fp_register_operand, lo_operand): New.
(mips_rtx_costs): Add TUNE_SB1 support.
(mips_issue_rate): Add comment. Add PROCESSOR_SB1 support.
(mips_use_dfa_pipeline_interface): Add PROCESSOR_SB1 support.
(mips_multipass_dfa_lookahead): New.
* config/mips/mips.h (MASK_FP_EXCEPTIONS, TARGET_FP_EXCEPTIONS,
TUNE_SB1): New.
(TARGET_SWITCHES): Add -mfp-exceptions support.
(TARGET_FP_EXCEPTIONS_DEFAULT): New.
(BRANCH_COST): Fix whitespace.
* config/mips/mips.md: Include sb1.md.
* config/mips/sb1.md: New file.
* doc/invoke.texi: Document -mfp-exceptions.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@80988 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/config/mips/sb1.md')
-rw-r--r-- | gcc/config/mips/sb1.md | 504 |
1 files changed, 504 insertions, 0 deletions
diff --git a/gcc/config/mips/sb1.md b/gcc/config/mips/sb1.md new file mode 100644 index 00000000000..a58992be525 --- /dev/null +++ b/gcc/config/mips/sb1.md @@ -0,0 +1,504 @@ +;; +;; DFA-based pipeline description for Broadcom SB-1 +;; + +;; The Broadcom SB-1 core is 4-way superscalar, in-order. It has 2 load/store +;; pipes (one of which can support some ALU operations), 2 alu pipes, 2 FP +;; pipes, and 1 MDMX pipes. It can issue 2 ls insns and 2 exe/fpu/mdmx insns +;; each cycle. + +;; We model the 4-way issue by ordering unit choices. The possible choices are +;; {ex1,fp1}|{ex0,fp0}|ls1|ls0. Instructions issue to the first eligible unit +;; in the list in most cases. Non-indexed load/stores issue to ls0 first. +;; simple alu operations issue to ls1 if it is still available, and their +;; operands are ready (no co-issue with loads), otherwise to the first +;; available ex unit. + +;; When exceptions are enabled, can only issue FP insns to fp1. This is +;; to ensure that instructions complete in order. The -mfp-exceptions option +;; can be used to specify whether the system has FP exceptions enabled or not. + +;; In 32-bit mode, dependent FP can't co-issue with load, and only one FP exe +;; insn can issue per cycle (fp1). + +;; The A1 MDMX pipe is separate from the FP pipes, but uses the same register +;; file. As a result, once an MDMX insn is issued, no FP insns can be issued +;; for 3 cycles. When an FP insn is issued, no MDMX insn can be issued for +;; 5 cycles. This is currently not handled because there is no MDMX insn +;; support as yet. + +;; +;; We use two automata. sb1_cpu_div is for the integer divides, which are +;; not pipelined. sb1_cpu is for everything else. +;; +(define_automaton "sb1_cpu, sb1_cpu_div") + +;; Load/store function units. +(define_cpu_unit "sb1_ls0" "sb1_cpu") +(define_cpu_unit "sb1_ls1" "sb1_cpu") + +;; CPU function units. +(define_cpu_unit "sb1_ex0" "sb1_cpu") +(define_cpu_unit "sb1_ex1" "sb1_cpu") + +;; The divide unit is not pipelined, and blocks hi/lo reads and writes. +(define_cpu_unit "sb1_div" "sb1_cpu_div") +;; DMULT block any multiply from issuing in the next cycle. +(define_cpu_unit "sb1_mul" "sb1_cpu") + +;; Floating-point units. +(define_cpu_unit "sb1_fp0" "sb1_cpu") +(define_cpu_unit "sb1_fp1" "sb1_cpu") + +;; Can only issue to one of the ex and fp pipes at a time. +(exclusion_set "sb1_ex0" "sb1_fp0") +(exclusion_set "sb1_ex1" "sb1_fp1") + +;; Define an SB-1 specific attribute to simplify some FP descriptions. +;; We can use 2 FP pipes only if we have 64-bit FP code, and exceptions are +;; disabled. + +(define_attr "sb1_fp_pipes" "one,two" + (cond [(and (ne (symbol_ref "TARGET_FLOAT64") (const_int 0)) + (eq (symbol_ref "TARGET_FP_EXCEPTIONS") (const_int 0))) + (const_string "two")] + (const_string "one"))) + +;; Define reservations for common combinations. + +;; For long cycle operations, the FPU has a 4 cycle pipeline that repeats, +;; effectively re-issuing the operation every 4 cycles. This means that we +;; can have at most 4 long-cycle operations per pipe. + +;; ??? The fdiv operations should be e.g. +;; sb1_fp1_4cycles*7" | "sb1_fp0_4cycle*7 +;; but the DFA is too large when we do that. Perhaps have to use scheduler +;; hooks here. + +;; ??? Try limiting scheduler to 2 long latency operations, and see if this +;; results in a usable DFA, and whether it helps code performance. + +;;(define_reservation "sb1_fp0_4cycles" "sb1_fp0, nothing*3") +;;(define_reservation "sb1_fp1_4cycles" "sb1_fp1, nothing*3") + +;; +;; The ordering of the instruction-execution-path/resource-usage +;; descriptions (also known as reservation RTL) is roughly ordered +;; based on the define attribute RTL for the "type" classification. +;; When modifying, remember that the first test that matches is the +;; reservation used! +;; + +(define_insn_reservation "ir_sb1_unknown" 1 + (and (eq_attr "cpu" "sb1") + (eq_attr "type" "unknown,multi")) + "sb1_ls0+sb1_ls1+sb1_ex0+sb1_ex1+sb1_fp0+sb1_fp1") + +;; predicted taken branch causes 2 cycle ifetch bubble. predicted not +;; taken branch causes 0 cycle ifetch bubble. mispredicted branch causes 8 +;; cycle ifetch bubble. We assume all branches predicted not taken. + +;; ??? This assumption that branches are predicated not taken should be +;; investigated. Maybe using 2 here will give better results. + +(define_insn_reservation "ir_sb1_branch" 0 + (and (eq_attr "cpu" "sb1") + (eq_attr "type" "branch,jump,call")) + "sb1_ex0") + +;; ??? This is 1 cycle for ldl/ldr to ldl/ldr when they use the same data +;; register as destination. + +;; ??? Can co-issue a load with a dependent arith insn if it executes on an EX +;; unit. Can not co-issue if the dependent insn executes on an LS unit. + +;; A load normally has a latency of zero cycles. In some cases, dependent +;; insns can be issued in the same cycle. However, a value of 1 gives +;; better performance in empirical testing. + +(define_insn_reservation "ir_sb1_load" 1 + (and (eq_attr "cpu" "sb1") + (eq_attr "type" "load,prefetch")) + "sb1_ls0 | sb1_ls1") + +;; Can not co-issue fpload with fp exe when in 32-bit mode. + +(define_insn_reservation "ir_sb1_fpload" 0 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "fpload") + (ne (symbol_ref "TARGET_FLOAT64") + (const_int 0)))) + "sb1_ls0 | sb1_ls1") + +(define_insn_reservation "ir_sb1_fpload_32bitfp" 1 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "fpload") + (eq (symbol_ref "TARGET_FLOAT64") + (const_int 0)))) + "sb1_ls0 | sb1_ls1") + +;; Indexed loads can only execute on LS1 pipe. + +(define_insn_reservation "ir_sb1_fpidxload" 0 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "fpidxload") + (ne (symbol_ref "TARGET_FLOAT64") + (const_int 0)))) + "sb1_ls1") + +(define_insn_reservation "ir_sb1_fpidxload_32bitfp" 1 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "fpidxload") + (eq (symbol_ref "TARGET_FLOAT64") + (const_int 0)))) + "sb1_ls1") + +;; prefx can only execute on the ls1 pipe. + +(define_insn_reservation "ir_sb1_prefetchx" 0 + (and (eq_attr "cpu" "sb1") + (eq_attr "type" "prefetchx")) + "sb1_ls1") + +;; ??? There is a 4.5 cycle latency if a store is followed by a load, and +;; there is a RAW dependency. + +(define_insn_reservation "ir_sb1_store" 1 + (and (eq_attr "cpu" "sb1") + (eq_attr "type" "store")) + "sb1_ls0+sb1_ex1 | sb1_ls0+sb1_ex0 | sb1_ls1+sb1_ex1 | sb1_ls1+sb1_ex0") + +(define_insn_reservation "ir_sb1_fpstore" 1 + (and (eq_attr "cpu" "sb1") + (eq_attr "type" "fpstore")) + "sb1_ls0+sb1_fp1 | sb1_ls0+sb1_fp0 | sb1_ls1+sb1_fp1 | sb1_ls1+sb1_fp0") + +;; Indexed stores can only execute on LS1 pipe. + +(define_insn_reservation "ir_sb1_fpidxstore" 1 + (and (eq_attr "cpu" "sb1") + (eq_attr "type" "fpidxstore")) + "sb1_ls1+sb1_fp1 | sb1_ls1+sb1_fp0") + +;; Load latencies are 3 cycles for one load to another load or store (address +;; only). This is 0 cycles for one load to a store using it as the data +;; written. + +;; This assumes that if a load is dependent on a previous insn, then it must +;; be an address dependence. + +(define_bypass 3 + "ir_sb1_load,ir_sb1_fpload,ir_sb1_fpload_32bitfp,ir_sb1_fpidxload, + ir_sb1_fpidxload_32bitfp" + "ir_sb1_load,ir_sb1_fpload,ir_sb1_fpload_32bitfp,ir_sb1_fpidxload, + ir_sb1_fpidxload_32bitfp,ir_sb1_prefetchx") + +(define_bypass 3 + "ir_sb1_load,ir_sb1_fpload,ir_sb1_fpload_32bitfp,ir_sb1_fpidxload, + ir_sb1_fpidxload_32bitfp" + "ir_sb1_store,ir_sb1_fpstore,ir_sb1_fpidxstore" + "store_data_bypass_p") + +;; Simple alu instructions can execute on the LS1 unit. + +;; ??? A simple alu insn issued on an LS unit has 0 cycle latency to an EX +;; insn, to a store (for data), and to an xfer insn. It has 1 cycle latency to +;; another LS insn (excluding store data). A simple alu insn issued on an EX +;; unit has a latency of 5 cycles when the results goes to a LS unit (exluding +;; store data), otherwise a latency of 1 cycle. + +;; ??? We can not handle latencies properly for simple alu instructions +;; within the DFA pipeline model. Latencies can be defined only from one +;; insn reservation to another. We can't make them depend on which function +;; unit was used. This isn't a DFA flaw. There is a conflict here, as we +;; need to know the latency before we can determine which unit will be +;; available, but we need to know which unit it is issued to before we can +;; compute the latency. Perhaps this can be handled via scheduler hooks. +;; This needs to be investigated. + +;; ??? Optimal scheduling taking the LS units into account seems to require +;; a pre-scheduling pass. We need to determine which instructions feed results +;; into store/load addresses, and thus benefit most from being issued to the +;; LS unit. Also, we need to prune the list to ensure we don't overschedule +;; insns to the LS unit, and that we don't conflict with insns that need LS1 +;; such as indexed loads. We then need to emit nops to ensure that simple +;; alu instructions that are not supposed to be scheduled to LS1 don't +;; accidentally end up there because LS1 is free when they are issued. This +;; will be a lot of work, and it isn't clear how useful it will be. + +;; Empirical testing shows that 2 gives the best result. + +(define_insn_reservation "ir_sb1_simple_alu" 2 + (and (eq_attr "cpu" "sb1") + (eq_attr "type" "const,arith")) + "sb1_ls1 | sb1_ex1 | sb1_ex0") + +;; ??? condmove also includes some FP instructions that execute on the FP +;; units. This needs to be clarified. + +(define_insn_reservation "ir_sb1_alu" 1 + (and (eq_attr "cpu" "sb1") + (eq_attr "type" "condmove,nop,shift")) + "sb1_ex1 | sb1_ex0") + +;; These are type arith/darith that only execute on the EX0 unit. + +(define_insn_reservation "ir_sb1_alu_0" 1 + (and (eq_attr "cpu" "sb1") + (eq_attr "type" "slt,clz,trap")) + "sb1_ex0") + +;; An alu insn issued on an EX unit has a latency of 5 cycles when the +;; result goes to a LS unit (excluding store data). + +;; This assumes that if a load is dependent on a previous insn, then it must +;; be an address dependence. + +(define_bypass 5 + "ir_sb1_alu,ir_sb1_alu_0,ir_sb1_mfhi,ir_sb1_mflo" + "ir_sb1_load,ir_sb1_fpload,ir_sb1_fpload_32bitfp,ir_sb1_fpidxload, + ir_sb1_fpidxload_32bitfp,ir_sb1_prefetchx") + +(define_bypass 5 + "ir_sb1_alu,ir_sb1_alu_0,ir_sb1_mfhi,ir_sb1_mflo" + "ir_sb1_store,ir_sb1_fpstore,ir_sb1_fpidxstore" + "store_data_bypass_p") + +;; mf{hi,lo} is 1 cycle. + +(define_insn_reservation "ir_sb1_mfhi" 1 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "mfhilo") + (not (match_operand 1 "lo_operand" "")))) + "sb1_ex1") + +(define_insn_reservation "ir_sb1_mflo" 1 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "mfhilo") + (match_operand 1 "lo_operand" ""))) + "sb1_ex1") + +;; mt{hi,lo} to mul/div is 4 cycles. + +(define_insn_reservation "ir_sb1_mthilo" 4 + (and (eq_attr "cpu" "sb1") + (eq_attr "type" "mthilo")) + "sb1_ex1") + +;; mt{hi,lo} to mf{hi,lo} is 3 cycles. + +(define_bypass 3 "ir_sb1_mthilo" "ir_sb1_mfhi,ir_sb1_mflo") + +;; multiply latency to an EX operation is 3 cycles. + +;; ??? Should check whether we need to make multiply conflict with moves +;; to/from hilo registers. + +(define_insn_reservation "ir_sb1_mulsi" 3 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "imul,imadd") + (eq_attr "mode" "SI"))) + "sb1_ex1+sb1_mul") + +;; muldi to mfhi is 4 cycles. +;; Blocks any other multiply insn issue for 1 cycle. + +(define_insn_reservation "ir_sb1_muldi" 4 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "imul") + (eq_attr "mode" "DI"))) + "sb1_ex1+sb1_mul, sb1_mul") + +;; muldi to mflo is 3 cycles. + +(define_bypass 3 "ir_sb1_muldi" "ir_sb1_mflo") + +;; mul latency is 7 cycles if the result is used by any LS insn. + +;; This assumes that if a load is dependent on a previous insn, then it must +;; be an address dependence. + +(define_bypass 7 + "ir_sb1_mulsi,ir_sb1_muldi" + "ir_sb1_load,ir_sb1_fpload,ir_sb1_fpload_32bitfp,ir_sb1_fpidxload, + ir_sb1_fpidxload_32bitfp,ir_sb1_prefetchx") + +(define_bypass 7 + "ir_sb1_mulsi,ir_sb1_muldi" + "ir_sb1_store,ir_sb1_fpstore,ir_sb1_fpidxstore" + "store_data_bypass_p") + +;; The divide unit is not pipelined. Divide busy is asserted in the 4th +;; cycle, and then deasserted on the latency cycle. So only one divide at +;; a time, but the first/last 4 cycles can overlap. + +;; ??? All divides block writes to hi/lo regs. hi/lo regs are written 4 cycles +;; after the latency cycle for divides (e.g. 40/72). dmult writes lo in +;; cycle 7, and hi in cycle 8. All other insns write hi/lo regs in cycle 7. +;; Default for output dependencies is the difference in latencies, which is +;; only 1 cycle off here, e.g. div to mtlo stalls for 32 cycles, but should +;; stall for 33 cycles. This does not seem significant enough to worry about. + +(define_insn_reservation "ir_sb1_divsi" 36 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "idiv") + (eq_attr "mode" "SI"))) + "sb1_ex1, nothing*3, sb1_div*32") + +(define_insn_reservation "ir_sb1_divdi" 68 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "idiv") + (eq_attr "mode" "DI"))) + "sb1_ex1, nothing*3, sb1_div*64") + +(define_insn_reservation "ir_sb1_fpu_2pipes" 4 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "fmove,fadd,fmul,fabs,fneg,fcvt") + (eq_attr "sb1_fp_pipes" "two"))) + "sb1_fp1 | sb1_fp0") + +(define_insn_reservation "ir_sb1_fpu_1pipe" 4 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "fmove,fadd,fmul,fabs,fneg,fcvt") + (eq_attr "sb1_fp_pipes" "one"))) + "sb1_fp1") + +;; ??? madd/msub 4-cycle latency to itself (same fr?), but 8 cycle latency +;; otherwise. + +;; ??? Blocks issue of another non-madd/msub after 4 cycles. + +(define_insn_reservation "ir_sb1_fmadd_2pipes" 8 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "fmadd") + (eq_attr "sb1_fp_pipes" "two"))) + "sb1_fp1 | sb1_fp0") + +(define_insn_reservation "ir_sb1_fmadd_1pipe" 8 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "fmadd") + (eq_attr "sb1_fp_pipes" "one"))) + "sb1_fp1") + +(define_insn_reservation "ir_sb1_fcmp" 4 + (and (eq_attr "cpu" "sb1") + (eq_attr "type" "fcmp")) + "sb1_fp1") + +;; mtc1 latency 5 cycles. + +(define_insn_reservation "ir_sb1_mtxfer" 5 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "xfer") + (match_operand 0 "fp_register_operand" ""))) + "sb1_fp0") + +;; mfc1 latency 1 cycle. + +(define_insn_reservation "ir_sb1_mfxfer" 1 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "xfer") + (not (match_operand 0 "fp_register_operand" "")))) + "sb1_fp0") + +;; ??? Can deliver at most 1 result per every 6 cycles because of issue +;; restrictions. + +(define_insn_reservation "ir_sb1_divsf_2pipes" 24 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "fdiv") + (and (eq_attr "mode" "SF") + (eq_attr "sb1_fp_pipes" "two")))) + "sb1_fp1 | sb1_fp0") + +(define_insn_reservation "ir_sb1_divsf_1pipes" 24 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "fdiv") + (and (eq_attr "mode" "SF") + (eq_attr "sb1_fp_pipes" "one")))) + "sb1_fp1") + +;; ??? Can deliver at most 1 result per every 8 cycles because of issue +;; restrictions. + +(define_insn_reservation "ir_sb1_divdf_2pipes" 32 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "fdiv") + (and (eq_attr "mode" "SF") + (eq_attr "sb1_fp_pipes" "two")))) + "sb1_fp1 | sb1_fp0") + +(define_insn_reservation "ir_sb1_divdf_1pipe" 32 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "fdiv") + (and (eq_attr "mode" "SF") + (eq_attr "sb1_fp_pipes" "one")))) + "sb1_fp1") + +;; ??? Can deliver at most 1 result per every 7 cycles because of issue +;; restrictions. + +(define_insn_reservation "ir_sb1_sqrtsf_2pipes" 28 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "fsqrt") + (and (eq_attr "mode" "SF") + (eq_attr "sb1_fp_pipes" "two")))) + "sb1_fp1 | sb1_fp0") + +(define_insn_reservation "ir_sb1_sqrtsf_1pipe" 28 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "fsqrt") + (and (eq_attr "mode" "SF") + (eq_attr "sb1_fp_pipes" "one")))) + "sb1_fp1") + +;; ??? Can deliver at most 1 result per every 10 cycles because of issue +;; restrictions. + +(define_insn_reservation "ir_sb1_sqrtdf_2pipes" 40 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "fsqrt") + (and (eq_attr "mode" "DF") + (eq_attr "sb1_fp_pipes" "two")))) + "sb1_fp1 | sb1_fp0") + +(define_insn_reservation "ir_sb1_sqrtdf_1pipe" 40 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "fsqrt") + (and (eq_attr "mode" "DF") + (eq_attr "sb1_fp_pipes" "one")))) + "sb1_fp1") + +;; ??? Can deliver at most 1 result per every 4 cycles because of issue +;; restrictions. + +(define_insn_reservation "ir_sb1_rsqrtsf_2pipes" 16 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "frsqrt") + (and (eq_attr "mode" "SF") + (eq_attr "sb1_fp_pipes" "two")))) + "sb1_fp1 | sb1_fp0") + +(define_insn_reservation "ir_sb1_rsqrtsf_1pipe" 16 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "frsqrt") + (and (eq_attr "mode" "SF") + (eq_attr "sb1_fp_pipes" "one")))) + "sb1_fp1") + +;; ??? Can deliver at most 1 result per every 7 cycles because of issue +;; restrictions. + +(define_insn_reservation "ir_sb1_rsqrtdf_2pipes" 28 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "frsqrt") + (and (eq_attr "mode" "DF") + (eq_attr "sb1_fp_pipes" "two")))) + "sb1_fp1 | sb1_fp0") + +(define_insn_reservation "ir_sb1_rsqrtdf_1pipe" 28 + (and (eq_attr "cpu" "sb1") + (and (eq_attr "type" "frsqrt") + (and (eq_attr "mode" "DF") + (eq_attr "sb1_fp_pipes" "one")))) + "sb1_fp1") |