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xemu/target/arm/translate-m-nocp.c
Peter Maydell 88137f787f target/arm: Handle FPU check for FPCXT_NS insns via vfp_access_check_m() 
Instead of open-coding the "take NOCP exception if FPU disabled,
otherwise call gen_preserve_fp_state()" code in the accessors for
FPCXT_NS, add an argument to vfp_access_check_m() which tells it to
skip the gen_update_fp_context() call, so we can use it for the
FPCXT_NS case.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210618141019.10671-8-peter.maydell@linaro.org
2021-06-21 16:49:38 +01:00

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/*
* ARM translation: M-profile NOCP special-case instructions
*
* Copyright (c) 2020 Linaro, Ltd.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "tcg/tcg-op.h"
#include "tcg/tcg-op-gvec.h"
#include "translate.h"
#include "translate-a32.h"
#include "decode-m-nocp.c.inc"
/*
* Decode VLLDM and VLSTM are nonstandard because:
* * if there is no FPU then these insns must NOP in
* Secure state and UNDEF in Nonsecure state
* * if there is an FPU then these insns do not have
* the usual behaviour that vfp_access_check() provides of
* being controlled by CPACR/NSACR enable bits or the
* lazy-stacking logic.
*/
static bool trans_VLLDM_VLSTM(DisasContext *s, arg_VLLDM_VLSTM *a)
{
TCGv_i32 fptr;
if (!arm_dc_feature(s, ARM_FEATURE_M) ||
!arm_dc_feature(s, ARM_FEATURE_V8)) {
return false;
}
if (a->op) {
/*
* T2 encoding ({D0-D31} reglist): v8.1M and up. We choose not
* to take the IMPDEF option to make memory accesses to the stack
* slots that correspond to the D16-D31 registers (discarding
* read data and writing UNKNOWN values), so for us the T2
* encoding behaves identically to the T1 encoding.
*/
if (!arm_dc_feature(s, ARM_FEATURE_V8_1M)) {
return false;
}
} else {
/*
* T1 encoding ({D0-D15} reglist); undef if we have 32 Dregs.
* This is currently architecturally impossible, but we add the
* check to stay in line with the pseudocode. Note that we must
* emit code for the UNDEF so it takes precedence over the NOCP.
*/
if (dc_isar_feature(aa32_simd_r32, s)) {
unallocated_encoding(s);
return true;
}
}
/*
* If not secure, UNDEF. We must emit code for this
* rather than returning false so that this takes
* precedence over the m-nocp.decode NOCP fallback.
*/
if (!s->v8m_secure) {
unallocated_encoding(s);
return true;
}
s->eci_handled = true;
/* If no fpu, NOP. */
if (!dc_isar_feature(aa32_vfp, s)) {
clear_eci_state(s);
return true;
}
fptr = load_reg(s, a->rn);
if (a->l) {
gen_helper_v7m_vlldm(cpu_env, fptr);
} else {
gen_helper_v7m_vlstm(cpu_env, fptr);
}
tcg_temp_free_i32(fptr);
clear_eci_state(s);
/* End the TB, because we have updated FP control bits */
s->base.is_jmp = DISAS_UPDATE_EXIT;
return true;
}
static bool trans_VSCCLRM(DisasContext *s, arg_VSCCLRM *a)
{
int btmreg, topreg;
TCGv_i64 zero;
TCGv_i32 aspen, sfpa;
if (!dc_isar_feature(aa32_m_sec_state, s)) {
/* Before v8.1M, fall through in decode to NOCP check */
return false;
}
/* Explicitly UNDEF because this takes precedence over NOCP */
if (!arm_dc_feature(s, ARM_FEATURE_M_MAIN) || !s->v8m_secure) {
unallocated_encoding(s);
return true;
}
s->eci_handled = true;
if (!dc_isar_feature(aa32_vfp_simd, s)) {
/* NOP if we have neither FP nor MVE */
clear_eci_state(s);
return true;
}
/*
* If FPCCR.ASPEN != 0 && CONTROL_S.SFPA == 0 then there is no
* active floating point context so we must NOP (without doing
* any lazy state preservation or the NOCP check).
*/
aspen = load_cpu_field(v7m.fpccr[M_REG_S]);
sfpa = load_cpu_field(v7m.control[M_REG_S]);
tcg_gen_andi_i32(aspen, aspen, R_V7M_FPCCR_ASPEN_MASK);
tcg_gen_xori_i32(aspen, aspen, R_V7M_FPCCR_ASPEN_MASK);
tcg_gen_andi_i32(sfpa, sfpa, R_V7M_CONTROL_SFPA_MASK);
tcg_gen_or_i32(sfpa, sfpa, aspen);
arm_gen_condlabel(s);
tcg_gen_brcondi_i32(TCG_COND_EQ, sfpa, 0, s->condlabel);
if (s->fp_excp_el != 0) {
gen_exception_insn(s, s->pc_curr, EXCP_NOCP,
syn_uncategorized(), s->fp_excp_el);
return true;
}
topreg = a->vd + a->imm - 1;
btmreg = a->vd;
/* Convert to Sreg numbers if the insn specified in Dregs */
if (a->size == 3) {
topreg = topreg * 2 + 1;
btmreg *= 2;
}
if (topreg > 63 || (topreg > 31 && !(topreg & 1))) {
/* UNPREDICTABLE: we choose to undef */
unallocated_encoding(s);
return true;
}
/* Silently ignore requests to clear D16-D31 if they don't exist */
if (topreg > 31 && !dc_isar_feature(aa32_simd_r32, s)) {
topreg = 31;
}
if (!vfp_access_check(s)) {
return true;
}
/* Zero the Sregs from btmreg to topreg inclusive. */
zero = tcg_const_i64(0);
if (btmreg & 1) {
write_neon_element64(zero, btmreg >> 1, 1, MO_32);
btmreg++;
}
for (; btmreg + 1 <= topreg; btmreg += 2) {
write_neon_element64(zero, btmreg >> 1, 0, MO_64);
}
if (btmreg == topreg) {
write_neon_element64(zero, btmreg >> 1, 0, MO_32);
btmreg++;
}
assert(btmreg == topreg + 1);
if (dc_isar_feature(aa32_mve, s)) {
TCGv_i32 z32 = tcg_const_i32(0);
store_cpu_field(z32, v7m.vpr);
}
clear_eci_state(s);
return true;
}
/*
* M-profile provides two different sets of instructions that can
* access floating point system registers: VMSR/VMRS (which move
* to/from a general purpose register) and VLDR/VSTR sysreg (which
* move directly to/from memory). In some cases there are also side
* effects which must happen after any write to memory (which could
* cause an exception). So we implement the common logic for the
* sysreg access in gen_M_fp_sysreg_write() and gen_M_fp_sysreg_read(),
* which take pointers to callback functions which will perform the
* actual "read/write general purpose register" and "read/write
* memory" operations.
*/
/*
* Emit code to store the sysreg to its final destination; frees the
* TCG temp 'value' it is passed. do_access is true to do the store,
* and false to skip it and only perform side-effects like base
* register writeback.
*/
typedef void fp_sysreg_storefn(DisasContext *s, void *opaque, TCGv_i32 value,
bool do_access);
/*
* Emit code to load the value to be copied to the sysreg; returns
* a new TCG temporary. do_access is true to do the store,
* and false to skip it and only perform side-effects like base
* register writeback.
*/
typedef TCGv_i32 fp_sysreg_loadfn(DisasContext *s, void *opaque,
bool do_access);
/* Common decode/access checks for fp sysreg read/write */
typedef enum FPSysRegCheckResult {
FPSysRegCheckFailed, /* caller should return false */
FPSysRegCheckDone, /* caller should return true */
FPSysRegCheckContinue, /* caller should continue generating code */
} FPSysRegCheckResult;
static FPSysRegCheckResult fp_sysreg_checks(DisasContext *s, int regno)
{
if (!dc_isar_feature(aa32_fpsp_v2, s) && !dc_isar_feature(aa32_mve, s)) {
return FPSysRegCheckFailed;
}
switch (regno) {
case ARM_VFP_FPSCR:
case QEMU_VFP_FPSCR_NZCV:
break;
case ARM_VFP_FPSCR_NZCVQC:
if (!arm_dc_feature(s, ARM_FEATURE_V8_1M)) {
return FPSysRegCheckFailed;
}
break;
case ARM_VFP_FPCXT_S:
case ARM_VFP_FPCXT_NS:
if (!arm_dc_feature(s, ARM_FEATURE_V8_1M)) {
return FPSysRegCheckFailed;
}
if (!s->v8m_secure) {
return FPSysRegCheckFailed;
}
break;
case ARM_VFP_VPR:
case ARM_VFP_P0:
if (!dc_isar_feature(aa32_mve, s)) {
return FPSysRegCheckFailed;
}
break;
default:
return FPSysRegCheckFailed;
}
/*
* FPCXT_NS is a special case: it has specific handling for
* "current FP state is inactive", and must do the PreserveFPState()
* but not the usual full set of actions done by ExecuteFPCheck().
* So we don't call vfp_access_check() and the callers must handle this.
*/
if (regno != ARM_VFP_FPCXT_NS && !vfp_access_check(s)) {
return FPSysRegCheckDone;
}
return FPSysRegCheckContinue;
}
static void gen_branch_fpInactive(DisasContext *s, TCGCond cond,
TCGLabel *label)
{
/*
* FPCXT_NS is a special case: it has specific handling for
* "current FP state is inactive", and must do the PreserveFPState()
* but not the usual full set of actions done by ExecuteFPCheck().
* We don't have a TB flag that matches the fpInactive check, so we
* do it at runtime as we don't expect FPCXT_NS accesses to be frequent.
*
* Emit code that checks fpInactive and does a conditional
* branch to label based on it:
* if cond is TCG_COND_NE then branch if fpInactive != 0 (ie if inactive)
* if cond is TCG_COND_EQ then branch if fpInactive == 0 (ie if active)
*/
assert(cond == TCG_COND_EQ || cond == TCG_COND_NE);
/* fpInactive = FPCCR_NS.ASPEN == 1 && CONTROL.FPCA == 0 */
TCGv_i32 aspen, fpca;
aspen = load_cpu_field(v7m.fpccr[M_REG_NS]);
fpca = load_cpu_field(v7m.control[M_REG_S]);
tcg_gen_andi_i32(aspen, aspen, R_V7M_FPCCR_ASPEN_MASK);
tcg_gen_xori_i32(aspen, aspen, R_V7M_FPCCR_ASPEN_MASK);
tcg_gen_andi_i32(fpca, fpca, R_V7M_CONTROL_FPCA_MASK);
tcg_gen_or_i32(fpca, fpca, aspen);
tcg_gen_brcondi_i32(tcg_invert_cond(cond), fpca, 0, label);
tcg_temp_free_i32(aspen);
tcg_temp_free_i32(fpca);
}
static bool gen_M_fp_sysreg_write(DisasContext *s, int regno,
fp_sysreg_loadfn *loadfn,
void *opaque)
{
/* Do a write to an M-profile floating point system register */
TCGv_i32 tmp;
TCGLabel *lab_end = NULL;
switch (fp_sysreg_checks(s, regno)) {
case FPSysRegCheckFailed:
return false;
case FPSysRegCheckDone:
return true;
case FPSysRegCheckContinue:
break;
}
switch (regno) {
case ARM_VFP_FPSCR:
tmp = loadfn(s, opaque, true);
gen_helper_vfp_set_fpscr(cpu_env, tmp);
tcg_temp_free_i32(tmp);
gen_lookup_tb(s);
break;
case ARM_VFP_FPSCR_NZCVQC:
{
TCGv_i32 fpscr;
tmp = loadfn(s, opaque, true);
if (dc_isar_feature(aa32_mve, s)) {
/* QC is only present for MVE; otherwise RES0 */
TCGv_i32 qc = tcg_temp_new_i32();
tcg_gen_andi_i32(qc, tmp, FPCR_QC);
/*
* The 4 vfp.qc[] fields need only be "zero" vs "non-zero";
* here writing the same value into all elements is simplest.
*/
tcg_gen_gvec_dup_i32(MO_32, offsetof(CPUARMState, vfp.qc),
16, 16, qc);
}
tcg_gen_andi_i32(tmp, tmp, FPCR_NZCV_MASK);
fpscr = load_cpu_field(vfp.xregs[ARM_VFP_FPSCR]);
tcg_gen_andi_i32(fpscr, fpscr, ~FPCR_NZCV_MASK);
tcg_gen_or_i32(fpscr, fpscr, tmp);
store_cpu_field(fpscr, vfp.xregs[ARM_VFP_FPSCR]);
tcg_temp_free_i32(tmp);
break;
}
case ARM_VFP_FPCXT_NS:
{
TCGLabel *lab_active = gen_new_label();
lab_end = gen_new_label();
gen_branch_fpInactive(s, TCG_COND_EQ, lab_active);
/*
* fpInactive case: write is a NOP, so only do side effects
* like register writeback before we branch to end
*/
loadfn(s, opaque, false);
tcg_gen_br(lab_end);
gen_set_label(lab_active);
/*
* !fpInactive: if FPU disabled, take NOCP exception;
* otherwise PreserveFPState(), and then FPCXT_NS writes
* behave the same as FPCXT_S writes.
*/
if (!vfp_access_check_m(s, true)) {
/*
* This was only a conditional exception, so override
* gen_exception_insn()'s default to DISAS_NORETURN
*/
s->base.is_jmp = DISAS_NEXT;
break;
}
}
/* fall through */
case ARM_VFP_FPCXT_S:
{
TCGv_i32 sfpa, control;
/*
* Set FPSCR and CONTROL.SFPA from value; the new FPSCR takes
* bits [27:0] from value and zeroes bits [31:28].
*/
tmp = loadfn(s, opaque, true);
sfpa = tcg_temp_new_i32();
tcg_gen_shri_i32(sfpa, tmp, 31);
control = load_cpu_field(v7m.control[M_REG_S]);
tcg_gen_deposit_i32(control, control, sfpa,
R_V7M_CONTROL_SFPA_SHIFT, 1);
store_cpu_field(control, v7m.control[M_REG_S]);
tcg_gen_andi_i32(tmp, tmp, ~FPCR_NZCV_MASK);
gen_helper_vfp_set_fpscr(cpu_env, tmp);
tcg_temp_free_i32(tmp);
tcg_temp_free_i32(sfpa);
break;
}
case ARM_VFP_VPR:
/* Behaves as NOP if not privileged */
if (IS_USER(s)) {
loadfn(s, opaque, false);
break;
}
tmp = loadfn(s, opaque, true);
store_cpu_field(tmp, v7m.vpr);
break;
case ARM_VFP_P0:
{
TCGv_i32 vpr;
tmp = loadfn(s, opaque, true);
vpr = load_cpu_field(v7m.vpr);
tcg_gen_deposit_i32(vpr, vpr, tmp,
R_V7M_VPR_P0_SHIFT, R_V7M_VPR_P0_LENGTH);
store_cpu_field(vpr, v7m.vpr);
tcg_temp_free_i32(tmp);
break;
}
default:
g_assert_not_reached();
}
if (lab_end) {
gen_set_label(lab_end);
}
return true;
}
static bool gen_M_fp_sysreg_read(DisasContext *s, int regno,
fp_sysreg_storefn *storefn,
void *opaque)
{
/* Do a read from an M-profile floating point system register */
TCGv_i32 tmp;
TCGLabel *lab_end = NULL;
bool lookup_tb = false;
switch (fp_sysreg_checks(s, regno)) {
case FPSysRegCheckFailed:
return false;
case FPSysRegCheckDone:
return true;
case FPSysRegCheckContinue:
break;
}
if (regno == ARM_VFP_FPSCR_NZCVQC && !dc_isar_feature(aa32_mve, s)) {
/* QC is RES0 without MVE, so NZCVQC simplifies to NZCV */
regno = QEMU_VFP_FPSCR_NZCV;
}
switch (regno) {
case ARM_VFP_FPSCR:
tmp = tcg_temp_new_i32();
gen_helper_vfp_get_fpscr(tmp, cpu_env);
storefn(s, opaque, tmp, true);
break;
case ARM_VFP_FPSCR_NZCVQC:
tmp = tcg_temp_new_i32();
gen_helper_vfp_get_fpscr(tmp, cpu_env);
tcg_gen_andi_i32(tmp, tmp, FPCR_NZCVQC_MASK);
storefn(s, opaque, tmp, true);
break;
case QEMU_VFP_FPSCR_NZCV:
/*
* Read just NZCV; this is a special case to avoid the
* helper call for the "VMRS to CPSR.NZCV" insn.
*/
tmp = load_cpu_field(vfp.xregs[ARM_VFP_FPSCR]);
tcg_gen_andi_i32(tmp, tmp, FPCR_NZCV_MASK);
storefn(s, opaque, tmp, true);
break;
case ARM_VFP_FPCXT_S:
{
TCGv_i32 control, sfpa, fpscr;
/* Bits [27:0] from FPSCR, bit [31] from CONTROL.SFPA */
tmp = tcg_temp_new_i32();
sfpa = tcg_temp_new_i32();
gen_helper_vfp_get_fpscr(tmp, cpu_env);
tcg_gen_andi_i32(tmp, tmp, ~FPCR_NZCV_MASK);
control = load_cpu_field(v7m.control[M_REG_S]);
tcg_gen_andi_i32(sfpa, control, R_V7M_CONTROL_SFPA_MASK);
tcg_gen_shli_i32(sfpa, sfpa, 31 - R_V7M_CONTROL_SFPA_SHIFT);
tcg_gen_or_i32(tmp, tmp, sfpa);
tcg_temp_free_i32(sfpa);
/*
* Store result before updating FPSCR etc, in case
* it is a memory write which causes an exception.
*/
storefn(s, opaque, tmp, true);
/*
* Now we must reset FPSCR from FPDSCR_NS, and clear
* CONTROL.SFPA; so we'll end the TB here.
*/
tcg_gen_andi_i32(control, control, ~R_V7M_CONTROL_SFPA_MASK);
store_cpu_field(control, v7m.control[M_REG_S]);
fpscr = load_cpu_field(v7m.fpdscr[M_REG_NS]);
gen_helper_vfp_set_fpscr(cpu_env, fpscr);
tcg_temp_free_i32(fpscr);
lookup_tb = true;
break;
}
case ARM_VFP_FPCXT_NS:
{
TCGv_i32 control, sfpa, fpscr, fpdscr, zero;
TCGLabel *lab_active = gen_new_label();
lookup_tb = true;
gen_branch_fpInactive(s, TCG_COND_EQ, lab_active);
/* fpInactive case: reads as FPDSCR_NS */
TCGv_i32 tmp = load_cpu_field(v7m.fpdscr[M_REG_NS]);
storefn(s, opaque, tmp, true);
lab_end = gen_new_label();
tcg_gen_br(lab_end);
gen_set_label(lab_active);
/*
* !fpInactive: if FPU disabled, take NOCP exception;
* otherwise PreserveFPState(), and then FPCXT_NS
* reads the same as FPCXT_S.
*/
if (!vfp_access_check_m(s, true)) {
/*
* This was only a conditional exception, so override
* gen_exception_insn()'s default to DISAS_NORETURN
*/
s->base.is_jmp = DISAS_NEXT;
break;
}
tmp = tcg_temp_new_i32();
sfpa = tcg_temp_new_i32();
fpscr = tcg_temp_new_i32();
gen_helper_vfp_get_fpscr(fpscr, cpu_env);
tcg_gen_andi_i32(tmp, fpscr, ~FPCR_NZCV_MASK);
control = load_cpu_field(v7m.control[M_REG_S]);
tcg_gen_andi_i32(sfpa, control, R_V7M_CONTROL_SFPA_MASK);
tcg_gen_shli_i32(sfpa, sfpa, 31 - R_V7M_CONTROL_SFPA_SHIFT);
tcg_gen_or_i32(tmp, tmp, sfpa);
tcg_temp_free_i32(control);
/* Store result before updating FPSCR, in case it faults */
storefn(s, opaque, tmp, true);
/* If SFPA is zero then set FPSCR from FPDSCR_NS */
fpdscr = load_cpu_field(v7m.fpdscr[M_REG_NS]);
zero = tcg_const_i32(0);
tcg_gen_movcond_i32(TCG_COND_EQ, fpscr, sfpa, zero, fpdscr, fpscr);
gen_helper_vfp_set_fpscr(cpu_env, fpscr);
tcg_temp_free_i32(zero);
tcg_temp_free_i32(sfpa);
tcg_temp_free_i32(fpdscr);
tcg_temp_free_i32(fpscr);
break;
}
case ARM_VFP_VPR:
/* Behaves as NOP if not privileged */
if (IS_USER(s)) {
storefn(s, opaque, NULL, false);
break;
}
tmp = load_cpu_field(v7m.vpr);
storefn(s, opaque, tmp, true);
break;
case ARM_VFP_P0:
tmp = load_cpu_field(v7m.vpr);
tcg_gen_extract_i32(tmp, tmp, R_V7M_VPR_P0_SHIFT, R_V7M_VPR_P0_LENGTH);
storefn(s, opaque, tmp, true);
break;
default:
g_assert_not_reached();
}
if (lab_end) {
gen_set_label(lab_end);
}
if (lookup_tb) {
gen_lookup_tb(s);
}
return true;
}
static void fp_sysreg_to_gpr(DisasContext *s, void *opaque, TCGv_i32 value,
bool do_access)
{
arg_VMSR_VMRS *a = opaque;
if (!do_access) {
return;
}
if (a->rt == 15) {
/* Set the 4 flag bits in the CPSR */
gen_set_nzcv(value);
tcg_temp_free_i32(value);
} else {
store_reg(s, a->rt, value);
}
}
static TCGv_i32 gpr_to_fp_sysreg(DisasContext *s, void *opaque, bool do_access)
{
arg_VMSR_VMRS *a = opaque;
if (!do_access) {
return NULL;
}
return load_reg(s, a->rt);
}
static bool trans_VMSR_VMRS(DisasContext *s, arg_VMSR_VMRS *a)
{
/*
* Accesses to R15 are UNPREDICTABLE; we choose to undef.
* FPSCR -> r15 is a special case which writes to the PSR flags;
* set a->reg to a special value to tell gen_M_fp_sysreg_read()
* we only care about the top 4 bits of FPSCR there.
*/
if (a->rt == 15) {
if (a->l && a->reg == ARM_VFP_FPSCR) {
a->reg = QEMU_VFP_FPSCR_NZCV;
} else {
return false;
}
}
if (a->l) {
/* VMRS, move FP system register to gp register */
return gen_M_fp_sysreg_read(s, a->reg, fp_sysreg_to_gpr, a);
} else {
/* VMSR, move gp register to FP system register */
return gen_M_fp_sysreg_write(s, a->reg, gpr_to_fp_sysreg, a);
}
}
static void fp_sysreg_to_memory(DisasContext *s, void *opaque, TCGv_i32 value,
bool do_access)
{
arg_vldr_sysreg *a = opaque;
uint32_t offset = a->imm;
TCGv_i32 addr;
if (!a->a) {
offset = -offset;
}
if (!do_access && !a->w) {
return;
}
addr = load_reg(s, a->rn);
if (a->p) {
tcg_gen_addi_i32(addr, addr, offset);
}
if (s->v8m_stackcheck && a->rn == 13 && a->w) {
gen_helper_v8m_stackcheck(cpu_env, addr);
}
if (do_access) {
gen_aa32_st_i32(s, value, addr, get_mem_index(s),
MO_UL | MO_ALIGN | s->be_data);
tcg_temp_free_i32(value);
}
if (a->w) {
/* writeback */
if (!a->p) {
tcg_gen_addi_i32(addr, addr, offset);
}
store_reg(s, a->rn, addr);
} else {
tcg_temp_free_i32(addr);
}
}
static TCGv_i32 memory_to_fp_sysreg(DisasContext *s, void *opaque,
bool do_access)
{
arg_vldr_sysreg *a = opaque;
uint32_t offset = a->imm;
TCGv_i32 addr;
TCGv_i32 value = NULL;
if (!a->a) {
offset = -offset;
}
if (!do_access && !a->w) {
return NULL;
}
addr = load_reg(s, a->rn);
if (a->p) {
tcg_gen_addi_i32(addr, addr, offset);
}
if (s->v8m_stackcheck && a->rn == 13 && a->w) {
gen_helper_v8m_stackcheck(cpu_env, addr);
}
if (do_access) {
value = tcg_temp_new_i32();
gen_aa32_ld_i32(s, value, addr, get_mem_index(s),
MO_UL | MO_ALIGN | s->be_data);
}
if (a->w) {
/* writeback */
if (!a->p) {
tcg_gen_addi_i32(addr, addr, offset);
}
store_reg(s, a->rn, addr);
} else {
tcg_temp_free_i32(addr);
}
return value;
}
static bool trans_VLDR_sysreg(DisasContext *s, arg_vldr_sysreg *a)
{
if (!arm_dc_feature(s, ARM_FEATURE_V8_1M)) {
return false;
}
if (a->rn == 15) {
return false;
}
return gen_M_fp_sysreg_write(s, a->reg, memory_to_fp_sysreg, a);
}
static bool trans_VSTR_sysreg(DisasContext *s, arg_vldr_sysreg *a)
{
if (!arm_dc_feature(s, ARM_FEATURE_V8_1M)) {
return false;
}
if (a->rn == 15) {
return false;
}
return gen_M_fp_sysreg_read(s, a->reg, fp_sysreg_to_memory, a);
}
static bool trans_NOCP(DisasContext *s, arg_nocp *a)
{
/*
* Handle M-profile early check for disabled coprocessor:
* all we need to do here is emit the NOCP exception if
* the coprocessor is disabled. Otherwise we return false
* and the real VFP/etc decode will handle the insn.
*/
assert(arm_dc_feature(s, ARM_FEATURE_M));
if (a->cp == 11) {
a->cp = 10;
}
if (arm_dc_feature(s, ARM_FEATURE_V8_1M) &&
(a->cp == 8 || a->cp == 9 || a->cp == 14 || a->cp == 15)) {
/* in v8.1M cp 8, 9, 14, 15 also are governed by the cp10 enable */
a->cp = 10;
}
if (a->cp != 10) {
gen_exception_insn(s, s->pc_curr, EXCP_NOCP,
syn_uncategorized(), default_exception_el(s));
return true;
}
if (s->fp_excp_el != 0) {
gen_exception_insn(s, s->pc_curr, EXCP_NOCP,
syn_uncategorized(), s->fp_excp_el);
return true;
}
return false;
}
static bool trans_NOCP_8_1(DisasContext *s, arg_nocp *a)
{
/* This range needs a coprocessor check for v8.1M and later only */
if (!arm_dc_feature(s, ARM_FEATURE_V8_1M)) {
return false;
}
return trans_NOCP(s, a);
}
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