From 4a08d4758faf4d6497a5f6fa6be6f048a5359420 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Sun, 22 Dec 2013 22:32:27 +0000 Subject: [PATCH] target-arm: A64: add support for ld/st pair MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch support the basic load and store pair instructions and includes the generic helper functions: * do_gpr_st() * do_fp_st() * do_gpr_ld() * do_fp_ld() * read_cpu_reg_sp() * gen_check_sp_alignment() The last function gen_check_sp_alignment() is a NULL op currently but put in place to make it easy to add SP alignment checking later. Signed-off-by: Alex Bennée Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson --- target-arm/translate-a64.c | 279 ++++++++++++++++++++++++++++++++++++- 1 file changed, 277 insertions(+), 2 deletions(-) diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c index 0a76130bb2..0c3b99417a 100644 --- a/target-arm/translate-a64.c +++ b/target-arm/translate-a64.c @@ -99,6 +99,15 @@ void aarch64_cpu_dump_state(CPUState *cs, FILE *f, cpu_fprintf(f, "\n"); } +static int get_mem_index(DisasContext *s) +{ +#ifdef CONFIG_USER_ONLY + return 1; +#else + return s->user; +#endif +} + void gen_a64_set_pc_im(uint64_t val) { tcg_gen_movi_i64(cpu_pc, val); @@ -250,6 +259,17 @@ static TCGv_i64 read_cpu_reg(DisasContext *s, int reg, int sf) return v; } +static TCGv_i64 read_cpu_reg_sp(DisasContext *s, int reg, int sf) +{ + TCGv_i64 v = new_tmp_a64(s); + if (sf) { + tcg_gen_mov_i64(v, cpu_X[reg]); + } else { + tcg_gen_ext32u_i64(v, cpu_X[reg]); + } + return v; +} + /* Set ZF and NF based on a 64 bit result. This is alas fiddlier * than the 32 bit equivalent. */ @@ -277,6 +297,126 @@ static inline void gen_logic_CC(int sf, TCGv_i64 result) tcg_gen_movi_i32(cpu_VF, 0); } +/* + * Load/Store generators + */ + +/* + * Store from GPR register to memory + */ +static void do_gpr_st(DisasContext *s, TCGv_i64 source, + TCGv_i64 tcg_addr, int size) +{ + g_assert(size <= 3); + tcg_gen_qemu_st_i64(source, tcg_addr, get_mem_index(s), MO_TE + size); +} + +/* + * Load from memory to GPR register + */ +static void do_gpr_ld(DisasContext *s, TCGv_i64 dest, TCGv_i64 tcg_addr, + int size, bool is_signed, bool extend) +{ + TCGMemOp memop = MO_TE + size; + + g_assert(size <= 3); + + if (is_signed) { + memop += MO_SIGN; + } + + tcg_gen_qemu_ld_i64(dest, tcg_addr, get_mem_index(s), memop); + + if (extend && is_signed) { + g_assert(size < 3); + tcg_gen_ext32u_i64(dest, dest); + } +} + +/* + * Store from FP register to memory + */ +static void do_fp_st(DisasContext *s, int srcidx, TCGv_i64 tcg_addr, int size) +{ + /* This writes the bottom N bits of a 128 bit wide vector to memory */ + int freg_offs = offsetof(CPUARMState, vfp.regs[srcidx * 2]); + TCGv_i64 tmp = tcg_temp_new_i64(); + + if (size < 4) { + switch (size) { + case 0: + tcg_gen_ld8u_i64(tmp, cpu_env, freg_offs); + break; + case 1: + tcg_gen_ld16u_i64(tmp, cpu_env, freg_offs); + break; + case 2: + tcg_gen_ld32u_i64(tmp, cpu_env, freg_offs); + break; + case 3: + tcg_gen_ld_i64(tmp, cpu_env, freg_offs); + break; + } + tcg_gen_qemu_st_i64(tmp, tcg_addr, get_mem_index(s), MO_TE + size); + } else { + TCGv_i64 tcg_hiaddr = tcg_temp_new_i64(); + tcg_gen_ld_i64(tmp, cpu_env, freg_offs); + tcg_gen_qemu_st_i64(tmp, tcg_addr, get_mem_index(s), MO_TEQ); + tcg_gen_qemu_st64(tmp, tcg_addr, get_mem_index(s)); + tcg_gen_ld_i64(tmp, cpu_env, freg_offs + sizeof(float64)); + tcg_gen_addi_i64(tcg_hiaddr, tcg_addr, 8); + tcg_gen_qemu_st_i64(tmp, tcg_hiaddr, get_mem_index(s), MO_TEQ); + tcg_temp_free_i64(tcg_hiaddr); + } + + tcg_temp_free_i64(tmp); +} + +/* + * Load from memory to FP register + */ +static void do_fp_ld(DisasContext *s, int destidx, TCGv_i64 tcg_addr, int size) +{ + /* This always zero-extends and writes to a full 128 bit wide vector */ + int freg_offs = offsetof(CPUARMState, vfp.regs[destidx * 2]); + TCGv_i64 tmplo = tcg_temp_new_i64(); + TCGv_i64 tmphi; + + if (size < 4) { + TCGMemOp memop = MO_TE + size; + tmphi = tcg_const_i64(0); + tcg_gen_qemu_ld_i64(tmplo, tcg_addr, get_mem_index(s), memop); + } else { + TCGv_i64 tcg_hiaddr; + tmphi = tcg_temp_new_i64(); + tcg_hiaddr = tcg_temp_new_i64(); + + tcg_gen_qemu_ld_i64(tmplo, tcg_addr, get_mem_index(s), MO_TEQ); + tcg_gen_addi_i64(tcg_hiaddr, tcg_addr, 8); + tcg_gen_qemu_ld_i64(tmphi, tcg_hiaddr, get_mem_index(s), MO_TEQ); + tcg_temp_free_i64(tcg_hiaddr); + } + + tcg_gen_st_i64(tmplo, cpu_env, freg_offs); + tcg_gen_st_i64(tmphi, cpu_env, freg_offs + sizeof(float64)); + + tcg_temp_free_i64(tmplo); + tcg_temp_free_i64(tmphi); +} + +static inline void gen_check_sp_alignment(DisasContext *s) +{ + /* The AArch64 architecture mandates that (if enabled via PSTATE + * or SCTLR bits) there is a check that SP is 16-aligned on every + * SP-relative load or store (with an exception generated if it is not). + * In line with general QEMU practice regarding misaligned accesses, + * we omit these checks for the sake of guest program performance. + * This function is provided as a hook so we can more easily add these + * checks in future (possibly as a "favour catching guest program bugs + * over speed" user selectable option). + */ +} + /* * the instruction disassembly implemented here matches * the instruction encoding classifications in chapter 3 (C3) @@ -620,10 +760,145 @@ static void disas_ld_lit(DisasContext *s, uint32_t insn) unsupported_encoding(s, insn); } -/* Load/store pair (all forms) */ +/* + * C5.6.80 LDNP (Load Pair - non-temporal hint) + * C5.6.81 LDP (Load Pair - non vector) + * C5.6.82 LDPSW (Load Pair Signed Word - non vector) + * C5.6.176 STNP (Store Pair - non-temporal hint) + * C5.6.177 STP (Store Pair - non vector) + * C6.3.165 LDNP (Load Pair of SIMD&FP - non-temporal hint) + * C6.3.165 LDP (Load Pair of SIMD&FP) + * C6.3.284 STNP (Store Pair of SIMD&FP - non-temporal hint) + * C6.3.284 STP (Store Pair of SIMD&FP) + * + * 31 30 29 27 26 25 24 23 22 21 15 14 10 9 5 4 0 + * +-----+-------+---+---+-------+---+-----------------------------+ + * | opc | 1 0 1 | V | 0 | index | L | imm7 | Rt2 | Rn | Rt | + * +-----+-------+---+---+-------+---+-------+-------+------+------+ + * + * opc: LDP/STP/LDNP/STNP 00 -> 32 bit, 10 -> 64 bit + * LDPSW 01 + * LDP/STP/LDNP/STNP (SIMD) 00 -> 32 bit, 01 -> 64 bit, 10 -> 128 bit + * V: 0 -> GPR, 1 -> Vector + * idx: 00 -> signed offset with non-temporal hint, 01 -> post-index, + * 10 -> signed offset, 11 -> pre-index + * L: 0 -> Store 1 -> Load + * + * Rt, Rt2 = GPR or SIMD registers to be stored + * Rn = general purpose register containing address + * imm7 = signed offset (multiple of 4 or 8 depending on size) + */ static void disas_ldst_pair(DisasContext *s, uint32_t insn) { - unsupported_encoding(s, insn); + int rt = extract32(insn, 0, 5); + int rn = extract32(insn, 5, 5); + int rt2 = extract32(insn, 10, 5); + int64_t offset = sextract32(insn, 15, 7); + int index = extract32(insn, 23, 2); + bool is_vector = extract32(insn, 26, 1); + bool is_load = extract32(insn, 22, 1); + int opc = extract32(insn, 30, 2); + + bool is_signed = false; + bool postindex = false; + bool wback = false; + + TCGv_i64 tcg_addr; /* calculated address */ + int size; + + if (opc == 3) { + unallocated_encoding(s); + return; + } + + if (is_vector) { + size = 2 + opc; + } else { + size = 2 + extract32(opc, 1, 1); + is_signed = extract32(opc, 0, 1); + if (!is_load && is_signed) { + unallocated_encoding(s); + return; + } + } + + switch (index) { + case 1: /* post-index */ + postindex = true; + wback = true; + break; + case 0: + /* signed offset with "non-temporal" hint. Since we don't emulate + * caches we don't care about hints to the cache system about + * data access patterns, and handle this identically to plain + * signed offset. + */ + if (is_signed) { + /* There is no non-temporal-hint version of LDPSW */ + unallocated_encoding(s); + return; + } + postindex = false; + break; + case 2: /* signed offset, rn not updated */ + postindex = false; + break; + case 3: /* pre-index */ + postindex = false; + wback = true; + break; + } + + offset <<= size; + + if (rn == 31) { + gen_check_sp_alignment(s); + } + + tcg_addr = read_cpu_reg_sp(s, rn, 1); + + if (!postindex) { + tcg_gen_addi_i64(tcg_addr, tcg_addr, offset); + } + + if (is_vector) { + if (is_load) { + do_fp_ld(s, rt, tcg_addr, size); + } else { + do_fp_st(s, rt, tcg_addr, size); + } + } else { + TCGv_i64 tcg_rt = cpu_reg(s, rt); + if (is_load) { + do_gpr_ld(s, tcg_rt, tcg_addr, size, is_signed, false); + } else { + do_gpr_st(s, tcg_rt, tcg_addr, size); + } + } + tcg_gen_addi_i64(tcg_addr, tcg_addr, 1 << size); + if (is_vector) { + if (is_load) { + do_fp_ld(s, rt2, tcg_addr, size); + } else { + do_fp_st(s, rt2, tcg_addr, size); + } + } else { + TCGv_i64 tcg_rt2 = cpu_reg(s, rt2); + if (is_load) { + do_gpr_ld(s, tcg_rt2, tcg_addr, size, is_signed, false); + } else { + do_gpr_st(s, tcg_rt2, tcg_addr, size); + } + } + + if (wback) { + if (postindex) { + tcg_gen_addi_i64(tcg_addr, tcg_addr, offset - (1 << size)); + } else { + tcg_gen_subi_i64(tcg_addr, tcg_addr, 1 << size); + } + tcg_gen_mov_i64(cpu_reg_sp(s, rn), tcg_addr); + } } /* Load/store register (all forms) */