target-arm: A64: add support for ld/st pair

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 <alex.bennee@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Peter Maydell 2013-12-22 22:32:27 +00:00
parent f976b09ea2
commit 4a08d4758f

View File

@ -99,6 +99,15 @@ void aarch64_cpu_dump_state(CPUState *cs, FILE *f,
cpu_fprintf(f, "\n"); 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) void gen_a64_set_pc_im(uint64_t val)
{ {
tcg_gen_movi_i64(cpu_pc, 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; 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 /* Set ZF and NF based on a 64 bit result. This is alas fiddlier
* than the 32 bit equivalent. * 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); 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 disassembly implemented here matches
* the instruction encoding classifications in chapter 3 (C3) * 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); 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) 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) */ /* Load/store register (all forms) */