From 87f9a7f0c8d5122c36743885158782c2348a6d21 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 24 Oct 2018 07:50:18 +0100 Subject: [PATCH] target/arm: Promote consecutive memory ops for aa64 For a sequence of loads or stores from a single register, little-endian operations can be promoted to an 8-byte op. This can reduce the number of operations by a factor of 8. Signed-off-by: Richard Henderson Message-id: 20181011205206.3552-5-richard.henderson@linaro.org Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell --- target/arm/translate-a64.c | 66 +++++++++++++++++++++++--------------- 1 file changed, 40 insertions(+), 26 deletions(-) diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c index 8e8d3a8fe9..d493b87687 100644 --- a/target/arm/translate-a64.c +++ b/target/arm/translate-a64.c @@ -1201,25 +1201,23 @@ static void write_vec_element_i32(DisasContext *s, TCGv_i32 tcg_src, /* Store from vector register to memory */ static void do_vec_st(DisasContext *s, int srcidx, int element, - TCGv_i64 tcg_addr, int size) + TCGv_i64 tcg_addr, int size, TCGMemOp endian) { - TCGMemOp memop = s->be_data + size; TCGv_i64 tcg_tmp = tcg_temp_new_i64(); read_vec_element(s, tcg_tmp, srcidx, element, size); - tcg_gen_qemu_st_i64(tcg_tmp, tcg_addr, get_mem_index(s), memop); + tcg_gen_qemu_st_i64(tcg_tmp, tcg_addr, get_mem_index(s), endian | size); tcg_temp_free_i64(tcg_tmp); } /* Load from memory to vector register */ static void do_vec_ld(DisasContext *s, int destidx, int element, - TCGv_i64 tcg_addr, int size) + TCGv_i64 tcg_addr, int size, TCGMemOp endian) { - TCGMemOp memop = s->be_data + size; TCGv_i64 tcg_tmp = tcg_temp_new_i64(); - tcg_gen_qemu_ld_i64(tcg_tmp, tcg_addr, get_mem_index(s), memop); + tcg_gen_qemu_ld_i64(tcg_tmp, tcg_addr, get_mem_index(s), endian | size); write_vec_element(s, tcg_tmp, destidx, element, size); tcg_temp_free_i64(tcg_tmp); @@ -3019,9 +3017,10 @@ static void disas_ldst_multiple_struct(DisasContext *s, uint32_t insn) bool is_postidx = extract32(insn, 23, 1); bool is_q = extract32(insn, 30, 1); TCGv_i64 tcg_addr, tcg_rn, tcg_ebytes; + TCGMemOp endian = s->be_data; - int ebytes = 1 << size; - int elements = (is_q ? 128 : 64) / (8 << size); + int ebytes; /* bytes per element */ + int elements; /* elements per vector */ int rpt; /* num iterations */ int selem; /* structure elements */ int r; @@ -3080,6 +3079,20 @@ static void disas_ldst_multiple_struct(DisasContext *s, uint32_t insn) gen_check_sp_alignment(s); } + /* For our purposes, bytes are always little-endian. */ + if (size == 0) { + endian = MO_LE; + } + + /* Consecutive little-endian elements from a single register + * can be promoted to a larger little-endian operation. + */ + if (selem == 1 && endian == MO_LE) { + size = 3; + } + ebytes = 1 << size; + elements = (is_q ? 16 : 8) / ebytes; + tcg_rn = cpu_reg_sp(s, rn); tcg_addr = tcg_temp_new_i64(); tcg_gen_mov_i64(tcg_addr, tcg_rn); @@ -3088,32 +3101,33 @@ static void disas_ldst_multiple_struct(DisasContext *s, uint32_t insn) for (r = 0; r < rpt; r++) { int e; for (e = 0; e < elements; e++) { - int tt = (rt + r) % 32; int xs; for (xs = 0; xs < selem; xs++) { + int tt = (rt + r + xs) % 32; if (is_store) { - do_vec_st(s, tt, e, tcg_addr, size); + do_vec_st(s, tt, e, tcg_addr, size, endian); } else { - do_vec_ld(s, tt, e, tcg_addr, size); - - /* For non-quad operations, setting a slice of the low - * 64 bits of the register clears the high 64 bits (in - * the ARM ARM pseudocode this is implicit in the fact - * that 'rval' is a 64 bit wide variable). - * For quad operations, we might still need to zero the - * high bits of SVE. We optimize by noticing that we only - * need to do this the first time we touch a register. - */ - if (e == 0 && (r == 0 || xs == selem - 1)) { - clear_vec_high(s, is_q, tt); - } + do_vec_ld(s, tt, e, tcg_addr, size, endian); } tcg_gen_add_i64(tcg_addr, tcg_addr, tcg_ebytes); - tt = (tt + 1) % 32; } } } + if (!is_store) { + /* For non-quad operations, setting a slice of the low + * 64 bits of the register clears the high 64 bits (in + * the ARM ARM pseudocode this is implicit in the fact + * that 'rval' is a 64 bit wide variable). + * For quad operations, we might still need to zero the + * high bits of SVE. + */ + for (r = 0; r < rpt * selem; r++) { + int tt = (rt + r) % 32; + clear_vec_high(s, is_q, tt); + } + } + if (is_postidx) { int rm = extract32(insn, 16, 5); if (rm == 31) { @@ -3234,9 +3248,9 @@ static void disas_ldst_single_struct(DisasContext *s, uint32_t insn) } else { /* Load/store one element per register */ if (is_load) { - do_vec_ld(s, rt, index, tcg_addr, scale); + do_vec_ld(s, rt, index, tcg_addr, scale, s->be_data); } else { - do_vec_st(s, rt, index, tcg_addr, scale); + do_vec_st(s, rt, index, tcg_addr, scale, s->be_data); } } tcg_gen_add_i64(tcg_addr, tcg_addr, tcg_ebytes);