From 77f33f44baf24c22848197aa80962c003dd7b3e2 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 31 Oct 2018 09:29:29 +0000 Subject: [PATCH] aarch64: Simplify LSE cas generation The cas insn is a single insn, and if expanded properly need not be split after reload. Use the proper inputs for the insn. * config/aarch64/aarch64.c (aarch64_expand_compare_and_swap): Force oldval into the rval register for TARGET_LSE; emit the compare during initial expansion so that it may be deleted if unused. (aarch64_gen_atomic_cas): Remove. * config/aarch64/atomics.md (@aarch64_compare_and_swap_lse): Change =&r to +r for operand 0; use match_dup for operand 2; remove is_weak and mod_f operands as unused. Drop the split and merge with... (@aarch64_atomic_cas): ... this pattern's output; remove. (@aarch64_compare_and_swap_lse): Similarly. (@aarch64_atomic_cas): Similarly. From-SVN: r265656 --- gcc/ChangeLog | 14 ++++ gcc/config/aarch64/aarch64-protos.h | 1 - gcc/config/aarch64/aarch64.c | 46 ++++------- gcc/config/aarch64/atomics.md | 121 ++++++++-------------------- 4 files changed, 63 insertions(+), 119 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 660bafb20c0..3c764c56f4e 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,17 @@ +2018-10-31 Richard Henderson + + * config/aarch64/aarch64.c (aarch64_expand_compare_and_swap): + Force oldval into the rval register for TARGET_LSE; emit the compare + during initial expansion so that it may be deleted if unused. + (aarch64_gen_atomic_cas): Remove. + * config/aarch64/atomics.md (@aarch64_compare_and_swap_lse): + Change =&r to +r for operand 0; use match_dup for operand 2; + remove is_weak and mod_f operands as unused. Drop the split + and merge with... + (@aarch64_atomic_cas): ... this pattern's output; remove. + (@aarch64_compare_and_swap_lse): Similarly. + (@aarch64_atomic_cas): Similarly. + 2018-10-31 Richard Biener * tree-eh.c (replace_trapping_overflow): Simplify ABS_EXPR case diff --git a/gcc/config/aarch64/aarch64-protos.h b/gcc/config/aarch64/aarch64-protos.h index 776e8696ebe..f662533c108 100644 --- a/gcc/config/aarch64/aarch64-protos.h +++ b/gcc/config/aarch64/aarch64-protos.h @@ -563,7 +563,6 @@ rtx aarch64_load_tp (rtx); void aarch64_expand_compare_and_swap (rtx op[]); void aarch64_split_compare_and_swap (rtx op[]); -void aarch64_gen_atomic_cas (rtx, rtx, rtx, rtx, rtx); bool aarch64_atomic_ldop_supported_p (enum rtx_code); void aarch64_gen_atomic_ldop (enum rtx_code, rtx, rtx, rtx, rtx, rtx); diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c index 54f57463e97..9d53cf97b4c 100644 --- a/gcc/config/aarch64/aarch64.c +++ b/gcc/config/aarch64/aarch64.c @@ -14620,16 +14620,27 @@ aarch64_expand_compare_and_swap (rtx operands[]) } if (TARGET_LSE) - emit_insn (gen_aarch64_compare_and_swap_lse (mode, rval, mem, oldval, - newval, is_weak, mod_s, - mod_f)); + { + /* The CAS insn requires oldval and rval overlap, but we need to + have a copy of oldval saved across the operation to tell if + the operation is successful. */ + if (mode == QImode || mode == HImode) + rval = copy_to_mode_reg (SImode, gen_lowpart (SImode, oldval)); + else if (reg_overlap_mentioned_p (rval, oldval)) + rval = copy_to_mode_reg (mode, oldval); + else + emit_move_insn (rval, oldval); + emit_insn (gen_aarch64_compare_and_swap_lse (mode, rval, mem, + newval, mod_s)); + aarch64_gen_compare_reg (EQ, rval, oldval); + } else emit_insn (gen_aarch64_compare_and_swap (mode, rval, mem, oldval, newval, is_weak, mod_s, mod_f)); - if (mode == QImode || mode == HImode) - emit_move_insn (operands[1], gen_lowpart (mode, rval)); + rval = gen_lowpart (mode, rval); + emit_move_insn (operands[1], rval); x = gen_rtx_REG (CCmode, CC_REGNUM); x = gen_rtx_EQ (SImode, x, const0_rtx); @@ -14679,31 +14690,6 @@ aarch64_emit_post_barrier (enum memmodel model) } } -/* Emit an atomic compare-and-swap operation. RVAL is the destination register - for the data in memory. EXPECTED is the value expected to be in memory. - DESIRED is the value to store to memory. MEM is the memory location. MODEL - is the memory ordering to use. */ - -void -aarch64_gen_atomic_cas (rtx rval, rtx mem, - rtx expected, rtx desired, - rtx model) -{ - machine_mode mode; - - mode = GET_MODE (mem); - - /* Move the expected value into the CAS destination register. */ - emit_insn (gen_rtx_SET (rval, expected)); - - /* Emit the CAS. */ - emit_insn (gen_aarch64_atomic_cas (mode, rval, mem, desired, model)); - - /* Compare the expected value with the value loaded by the CAS, to establish - whether the swap was made. */ - aarch64_gen_compare_reg (EQ, rval, expected); -} - /* Split a compare and swap pattern. */ void diff --git a/gcc/config/aarch64/atomics.md b/gcc/config/aarch64/atomics.md index bba8e9e9c8e..22660850af1 100644 --- a/gcc/config/aarch64/atomics.md +++ b/gcc/config/aarch64/atomics.md @@ -85,56 +85,50 @@ } ) -(define_insn_and_split "@aarch64_compare_and_swap_lse" - [(set (reg:CC CC_REGNUM) ;; bool out - (unspec_volatile:CC [(const_int 0)] UNSPECV_ATOMIC_CMPSW)) - (set (match_operand:SI 0 "register_operand" "=&r") ;; val out +(define_insn "@aarch64_compare_and_swap_lse" + [(set (match_operand:SI 0 "register_operand" "+r") ;; val out (zero_extend:SI - (match_operand:SHORT 1 "aarch64_sync_memory_operand" "+Q"))) ;; memory + (match_operand:SHORT 1 "aarch64_sync_memory_operand" "+Q"))) ;; memory (set (match_dup 1) (unspec_volatile:SHORT - [(match_operand:SI 2 "aarch64_plus_operand" "rI") ;; expected - (match_operand:SHORT 3 "aarch64_reg_or_zero" "rZ") ;; desired - (match_operand:SI 4 "const_int_operand") ;; is_weak - (match_operand:SI 5 "const_int_operand") ;; mod_s - (match_operand:SI 6 "const_int_operand")] ;; mod_f + [(match_dup 0) ;; expected + (match_operand:SHORT 2 "aarch64_reg_or_zero" "rZ") ;; desired + (match_operand:SI 3 "const_int_operand")] ;; mod_s UNSPECV_ATOMIC_CMPSW))] "TARGET_LSE" - "#" - "&& reload_completed" - [(const_int 0)] - { - aarch64_gen_atomic_cas (operands[0], operands[1], - operands[2], operands[3], - operands[5]); - DONE; - } -) +{ + enum memmodel model = memmodel_from_int (INTVAL (operands[3])); + if (is_mm_relaxed (model)) + return "cas\t%0, %2, %1"; + else if (is_mm_acquire (model) || is_mm_consume (model)) + return "casa\t%0, %2, %1"; + else if (is_mm_release (model)) + return "casl\t%0, %2, %1"; + else + return "casal\t%0, %2, %1"; +}) -(define_insn_and_split "@aarch64_compare_and_swap_lse" - [(set (reg:CC CC_REGNUM) ;; bool out - (unspec_volatile:CC [(const_int 0)] UNSPECV_ATOMIC_CMPSW)) - (set (match_operand:GPI 0 "register_operand" "=&r") ;; val out +(define_insn "@aarch64_compare_and_swap_lse" + [(set (match_operand:GPI 0 "register_operand" "+r") ;; val out (match_operand:GPI 1 "aarch64_sync_memory_operand" "+Q")) ;; memory (set (match_dup 1) (unspec_volatile:GPI - [(match_operand:GPI 2 "aarch64_plus_operand" "rI") ;; expect - (match_operand:GPI 3 "aarch64_reg_or_zero" "rZ") ;; desired - (match_operand:SI 4 "const_int_operand") ;; is_weak - (match_operand:SI 5 "const_int_operand") ;; mod_s - (match_operand:SI 6 "const_int_operand")] ;; mod_f + [(match_dup 0) ;; expected + (match_operand:GPI 2 "aarch64_reg_or_zero" "rZ") ;; desired + (match_operand:SI 3 "const_int_operand")] ;; mod_s UNSPECV_ATOMIC_CMPSW))] "TARGET_LSE" - "#" - "&& reload_completed" - [(const_int 0)] - { - aarch64_gen_atomic_cas (operands[0], operands[1], - operands[2], operands[3], - operands[5]); - DONE; - } -) +{ + enum memmodel model = memmodel_from_int (INTVAL (operands[3])); + if (is_mm_relaxed (model)) + return "cas\t%0, %2, %1"; + else if (is_mm_acquire (model) || is_mm_consume (model)) + return "casa\t%0, %2, %1"; + else if (is_mm_release (model)) + return "casl\t%0, %2, %1"; + else + return "casal\t%0, %2, %1"; +}) (define_expand "atomic_exchange" [(match_operand:ALLI 0 "register_operand" "") @@ -610,55 +604,6 @@ return "swpal\t%2, %0, %1"; }) -;; Atomic compare-and-swap: HI and smaller modes. - -(define_insn "@aarch64_atomic_cas" - [(set (match_operand:SI 0 "register_operand" "+&r") ;; out - (zero_extend:SI - (match_operand:SHORT 1 "aarch64_sync_memory_operand" "+Q"))) ;; memory. - (set (match_dup 1) - (unspec_volatile:SHORT - [(match_dup 0) - (match_operand:SHORT 2 "aarch64_reg_or_zero" "rZ") ;; value. - (match_operand:SI 3 "const_int_operand" "")] ;; model. - UNSPECV_ATOMIC_CAS))] - "TARGET_LSE && reload_completed" -{ - enum memmodel model = memmodel_from_int (INTVAL (operands[3])); - if (is_mm_relaxed (model)) - return "cas\t%0, %2, %1"; - else if (is_mm_acquire (model) || is_mm_consume (model)) - return "casa\t%0, %2, %1"; - else if (is_mm_release (model)) - return "casl\t%0, %2, %1"; - else - return "casal\t%0, %2, %1"; -}) - -;; Atomic compare-and-swap: SI and larger modes. - -(define_insn "@aarch64_atomic_cas" - [(set (match_operand:GPI 0 "register_operand" "+&r") ;; out - (match_operand:GPI 1 "aarch64_sync_memory_operand" "+Q")) ;; memory. - (set (match_dup 1) - (unspec_volatile:GPI - [(match_dup 0) - (match_operand:GPI 2 "aarch64_reg_or_zero" "rZ") ;; value. - (match_operand:SI 3 "const_int_operand" "")] ;; model. - UNSPECV_ATOMIC_CAS))] - "TARGET_LSE && reload_completed" -{ - enum memmodel model = memmodel_from_int (INTVAL (operands[3])); - if (is_mm_relaxed (model)) - return "cas\t%0, %2, %1"; - else if (is_mm_acquire (model) || is_mm_consume (model)) - return "casa\t%0, %2, %1"; - else if (is_mm_release (model)) - return "casl\t%0, %2, %1"; - else - return "casal\t%0, %2, %1"; -}) - ;; Atomic load-op: Load data, operate, store result, keep data. (define_insn "@aarch64_atomic_load" -- 2.30.2