qemu/target/arm/translate-vfp.inc.c
Peter Maydell 9851ed9269 target/arm: Convert "double-precision" register moves to decodetree
Convert the "double-precision" register moves to decodetree:
this covers VMOV scalar-to-gpreg, VMOV gpreg-to-scalar and VDUP.

Note that the conversion process has tightened up a few of the
UNDEF encoding checks: we now correctly forbid:
 * VMOV-to-gpr with U:opc1:opc2 == 10x00 or x0x10
 * VMOV-from-gpr with opc1:opc2 == 0x10
 * VDUP with B:E == 11
 * VDUP with Q == 1 and Vn<0> == 1

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
The accesses of elements < 32 bits could be improved by doing
direct ld/st of the right size rather than 32-bit read-and-shift
or read-modify-write, but we leave this for later cleanup,
since this series is generally trying to stick to fixing
the decode.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2019-06-13 15:14:04 +01:00

625 lines
17 KiB
C

/*
* ARM translation: AArch32 VFP instructions
*
* Copyright (c) 2003 Fabrice Bellard
* Copyright (c) 2005-2007 CodeSourcery
* Copyright (c) 2007 OpenedHand, Ltd.
* Copyright (c) 2019 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 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/>.
*/
/*
* This file is intended to be included from translate.c; it uses
* some macros and definitions provided by that file.
* It might be possible to convert it to a standalone .c file eventually.
*/
/* Include the generated VFP decoder */
#include "decode-vfp.inc.c"
#include "decode-vfp-uncond.inc.c"
/*
* Check that VFP access is enabled. If it is, do the necessary
* M-profile lazy-FP handling and then return true.
* If not, emit code to generate an appropriate exception and
* return false.
* The ignore_vfp_enabled argument specifies that we should ignore
* whether VFP is enabled via FPEXC[EN]: this should be true for FMXR/FMRX
* accesses to FPSID, FPEXC, MVFR0, MVFR1, MVFR2, and false for all other insns.
*/
static bool full_vfp_access_check(DisasContext *s, bool ignore_vfp_enabled)
{
if (s->fp_excp_el) {
if (arm_dc_feature(s, ARM_FEATURE_M)) {
gen_exception_insn(s, 4, EXCP_NOCP, syn_uncategorized(),
s->fp_excp_el);
} else {
gen_exception_insn(s, 4, EXCP_UDEF,
syn_fp_access_trap(1, 0xe, false),
s->fp_excp_el);
}
return false;
}
if (!s->vfp_enabled && !ignore_vfp_enabled) {
assert(!arm_dc_feature(s, ARM_FEATURE_M));
gen_exception_insn(s, 4, EXCP_UDEF, syn_uncategorized(),
default_exception_el(s));
return false;
}
if (arm_dc_feature(s, ARM_FEATURE_M)) {
/* Handle M-profile lazy FP state mechanics */
/* Trigger lazy-state preservation if necessary */
if (s->v7m_lspact) {
/*
* Lazy state saving affects external memory and also the NVIC,
* so we must mark it as an IO operation for icount.
*/
if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
gen_io_start();
}
gen_helper_v7m_preserve_fp_state(cpu_env);
if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) {
gen_io_end();
}
/*
* If the preserve_fp_state helper doesn't throw an exception
* then it will clear LSPACT; we don't need to repeat this for
* any further FP insns in this TB.
*/
s->v7m_lspact = false;
}
/* Update ownership of FP context: set FPCCR.S to match current state */
if (s->v8m_fpccr_s_wrong) {
TCGv_i32 tmp;
tmp = load_cpu_field(v7m.fpccr[M_REG_S]);
if (s->v8m_secure) {
tcg_gen_ori_i32(tmp, tmp, R_V7M_FPCCR_S_MASK);
} else {
tcg_gen_andi_i32(tmp, tmp, ~R_V7M_FPCCR_S_MASK);
}
store_cpu_field(tmp, v7m.fpccr[M_REG_S]);
/* Don't need to do this for any further FP insns in this TB */
s->v8m_fpccr_s_wrong = false;
}
if (s->v7m_new_fp_ctxt_needed) {
/*
* Create new FP context by updating CONTROL.FPCA, CONTROL.SFPA
* and the FPSCR.
*/
TCGv_i32 control, fpscr;
uint32_t bits = R_V7M_CONTROL_FPCA_MASK;
fpscr = load_cpu_field(v7m.fpdscr[s->v8m_secure]);
gen_helper_vfp_set_fpscr(cpu_env, fpscr);
tcg_temp_free_i32(fpscr);
/*
* We don't need to arrange to end the TB, because the only
* parts of FPSCR which we cache in the TB flags are the VECLEN
* and VECSTRIDE, and those don't exist for M-profile.
*/
if (s->v8m_secure) {
bits |= R_V7M_CONTROL_SFPA_MASK;
}
control = load_cpu_field(v7m.control[M_REG_S]);
tcg_gen_ori_i32(control, control, bits);
store_cpu_field(control, v7m.control[M_REG_S]);
/* Don't need to do this for any further FP insns in this TB */
s->v7m_new_fp_ctxt_needed = false;
}
}
return true;
}
/*
* The most usual kind of VFP access check, for everything except
* FMXR/FMRX to the always-available special registers.
*/
static bool vfp_access_check(DisasContext *s)
{
return full_vfp_access_check(s, false);
}
static bool trans_VSEL(DisasContext *s, arg_VSEL *a)
{
uint32_t rd, rn, rm;
bool dp = a->dp;
if (!dc_isar_feature(aa32_vsel, s)) {
return false;
}
/* UNDEF accesses to D16-D31 if they don't exist */
if (dp && !dc_isar_feature(aa32_fp_d32, s) &&
((a->vm | a->vn | a->vd) & 0x10)) {
return false;
}
rd = a->vd;
rn = a->vn;
rm = a->vm;
if (!vfp_access_check(s)) {
return true;
}
if (dp) {
TCGv_i64 frn, frm, dest;
TCGv_i64 tmp, zero, zf, nf, vf;
zero = tcg_const_i64(0);
frn = tcg_temp_new_i64();
frm = tcg_temp_new_i64();
dest = tcg_temp_new_i64();
zf = tcg_temp_new_i64();
nf = tcg_temp_new_i64();
vf = tcg_temp_new_i64();
tcg_gen_extu_i32_i64(zf, cpu_ZF);
tcg_gen_ext_i32_i64(nf, cpu_NF);
tcg_gen_ext_i32_i64(vf, cpu_VF);
neon_load_reg64(frn, rn);
neon_load_reg64(frm, rm);
switch (a->cc) {
case 0: /* eq: Z */
tcg_gen_movcond_i64(TCG_COND_EQ, dest, zf, zero,
frn, frm);
break;
case 1: /* vs: V */
tcg_gen_movcond_i64(TCG_COND_LT, dest, vf, zero,
frn, frm);
break;
case 2: /* ge: N == V -> N ^ V == 0 */
tmp = tcg_temp_new_i64();
tcg_gen_xor_i64(tmp, vf, nf);
tcg_gen_movcond_i64(TCG_COND_GE, dest, tmp, zero,
frn, frm);
tcg_temp_free_i64(tmp);
break;
case 3: /* gt: !Z && N == V */
tcg_gen_movcond_i64(TCG_COND_NE, dest, zf, zero,
frn, frm);
tmp = tcg_temp_new_i64();
tcg_gen_xor_i64(tmp, vf, nf);
tcg_gen_movcond_i64(TCG_COND_GE, dest, tmp, zero,
dest, frm);
tcg_temp_free_i64(tmp);
break;
}
neon_store_reg64(dest, rd);
tcg_temp_free_i64(frn);
tcg_temp_free_i64(frm);
tcg_temp_free_i64(dest);
tcg_temp_free_i64(zf);
tcg_temp_free_i64(nf);
tcg_temp_free_i64(vf);
tcg_temp_free_i64(zero);
} else {
TCGv_i32 frn, frm, dest;
TCGv_i32 tmp, zero;
zero = tcg_const_i32(0);
frn = tcg_temp_new_i32();
frm = tcg_temp_new_i32();
dest = tcg_temp_new_i32();
neon_load_reg32(frn, rn);
neon_load_reg32(frm, rm);
switch (a->cc) {
case 0: /* eq: Z */
tcg_gen_movcond_i32(TCG_COND_EQ, dest, cpu_ZF, zero,
frn, frm);
break;
case 1: /* vs: V */
tcg_gen_movcond_i32(TCG_COND_LT, dest, cpu_VF, zero,
frn, frm);
break;
case 2: /* ge: N == V -> N ^ V == 0 */
tmp = tcg_temp_new_i32();
tcg_gen_xor_i32(tmp, cpu_VF, cpu_NF);
tcg_gen_movcond_i32(TCG_COND_GE, dest, tmp, zero,
frn, frm);
tcg_temp_free_i32(tmp);
break;
case 3: /* gt: !Z && N == V */
tcg_gen_movcond_i32(TCG_COND_NE, dest, cpu_ZF, zero,
frn, frm);
tmp = tcg_temp_new_i32();
tcg_gen_xor_i32(tmp, cpu_VF, cpu_NF);
tcg_gen_movcond_i32(TCG_COND_GE, dest, tmp, zero,
dest, frm);
tcg_temp_free_i32(tmp);
break;
}
neon_store_reg32(dest, rd);
tcg_temp_free_i32(frn);
tcg_temp_free_i32(frm);
tcg_temp_free_i32(dest);
tcg_temp_free_i32(zero);
}
return true;
}
static bool trans_VMINMAXNM(DisasContext *s, arg_VMINMAXNM *a)
{
uint32_t rd, rn, rm;
bool dp = a->dp;
bool vmin = a->op;
TCGv_ptr fpst;
if (!dc_isar_feature(aa32_vminmaxnm, s)) {
return false;
}
/* UNDEF accesses to D16-D31 if they don't exist */
if (dp && !dc_isar_feature(aa32_fp_d32, s) &&
((a->vm | a->vn | a->vd) & 0x10)) {
return false;
}
rd = a->vd;
rn = a->vn;
rm = a->vm;
if (!vfp_access_check(s)) {
return true;
}
fpst = get_fpstatus_ptr(0);
if (dp) {
TCGv_i64 frn, frm, dest;
frn = tcg_temp_new_i64();
frm = tcg_temp_new_i64();
dest = tcg_temp_new_i64();
neon_load_reg64(frn, rn);
neon_load_reg64(frm, rm);
if (vmin) {
gen_helper_vfp_minnumd(dest, frn, frm, fpst);
} else {
gen_helper_vfp_maxnumd(dest, frn, frm, fpst);
}
neon_store_reg64(dest, rd);
tcg_temp_free_i64(frn);
tcg_temp_free_i64(frm);
tcg_temp_free_i64(dest);
} else {
TCGv_i32 frn, frm, dest;
frn = tcg_temp_new_i32();
frm = tcg_temp_new_i32();
dest = tcg_temp_new_i32();
neon_load_reg32(frn, rn);
neon_load_reg32(frm, rm);
if (vmin) {
gen_helper_vfp_minnums(dest, frn, frm, fpst);
} else {
gen_helper_vfp_maxnums(dest, frn, frm, fpst);
}
neon_store_reg32(dest, rd);
tcg_temp_free_i32(frn);
tcg_temp_free_i32(frm);
tcg_temp_free_i32(dest);
}
tcg_temp_free_ptr(fpst);
return true;
}
/*
* Table for converting the most common AArch32 encoding of
* rounding mode to arm_fprounding order (which matches the
* common AArch64 order); see ARM ARM pseudocode FPDecodeRM().
*/
static const uint8_t fp_decode_rm[] = {
FPROUNDING_TIEAWAY,
FPROUNDING_TIEEVEN,
FPROUNDING_POSINF,
FPROUNDING_NEGINF,
};
static bool trans_VRINT(DisasContext *s, arg_VRINT *a)
{
uint32_t rd, rm;
bool dp = a->dp;
TCGv_ptr fpst;
TCGv_i32 tcg_rmode;
int rounding = fp_decode_rm[a->rm];
if (!dc_isar_feature(aa32_vrint, s)) {
return false;
}
/* UNDEF accesses to D16-D31 if they don't exist */
if (dp && !dc_isar_feature(aa32_fp_d32, s) &&
((a->vm | a->vd) & 0x10)) {
return false;
}
rd = a->vd;
rm = a->vm;
if (!vfp_access_check(s)) {
return true;
}
fpst = get_fpstatus_ptr(0);
tcg_rmode = tcg_const_i32(arm_rmode_to_sf(rounding));
gen_helper_set_rmode(tcg_rmode, tcg_rmode, fpst);
if (dp) {
TCGv_i64 tcg_op;
TCGv_i64 tcg_res;
tcg_op = tcg_temp_new_i64();
tcg_res = tcg_temp_new_i64();
neon_load_reg64(tcg_op, rm);
gen_helper_rintd(tcg_res, tcg_op, fpst);
neon_store_reg64(tcg_res, rd);
tcg_temp_free_i64(tcg_op);
tcg_temp_free_i64(tcg_res);
} else {
TCGv_i32 tcg_op;
TCGv_i32 tcg_res;
tcg_op = tcg_temp_new_i32();
tcg_res = tcg_temp_new_i32();
neon_load_reg32(tcg_op, rm);
gen_helper_rints(tcg_res, tcg_op, fpst);
neon_store_reg32(tcg_res, rd);
tcg_temp_free_i32(tcg_op);
tcg_temp_free_i32(tcg_res);
}
gen_helper_set_rmode(tcg_rmode, tcg_rmode, fpst);
tcg_temp_free_i32(tcg_rmode);
tcg_temp_free_ptr(fpst);
return true;
}
static bool trans_VCVT(DisasContext *s, arg_VCVT *a)
{
uint32_t rd, rm;
bool dp = a->dp;
TCGv_ptr fpst;
TCGv_i32 tcg_rmode, tcg_shift;
int rounding = fp_decode_rm[a->rm];
bool is_signed = a->op;
if (!dc_isar_feature(aa32_vcvt_dr, s)) {
return false;
}
/* UNDEF accesses to D16-D31 if they don't exist */
if (dp && !dc_isar_feature(aa32_fp_d32, s) && (a->vm & 0x10)) {
return false;
}
rd = a->vd;
rm = a->vm;
if (!vfp_access_check(s)) {
return true;
}
fpst = get_fpstatus_ptr(0);
tcg_shift = tcg_const_i32(0);
tcg_rmode = tcg_const_i32(arm_rmode_to_sf(rounding));
gen_helper_set_rmode(tcg_rmode, tcg_rmode, fpst);
if (dp) {
TCGv_i64 tcg_double, tcg_res;
TCGv_i32 tcg_tmp;
tcg_double = tcg_temp_new_i64();
tcg_res = tcg_temp_new_i64();
tcg_tmp = tcg_temp_new_i32();
neon_load_reg64(tcg_double, rm);
if (is_signed) {
gen_helper_vfp_tosld(tcg_res, tcg_double, tcg_shift, fpst);
} else {
gen_helper_vfp_tould(tcg_res, tcg_double, tcg_shift, fpst);
}
tcg_gen_extrl_i64_i32(tcg_tmp, tcg_res);
neon_store_reg32(tcg_tmp, rd);
tcg_temp_free_i32(tcg_tmp);
tcg_temp_free_i64(tcg_res);
tcg_temp_free_i64(tcg_double);
} else {
TCGv_i32 tcg_single, tcg_res;
tcg_single = tcg_temp_new_i32();
tcg_res = tcg_temp_new_i32();
neon_load_reg32(tcg_single, rm);
if (is_signed) {
gen_helper_vfp_tosls(tcg_res, tcg_single, tcg_shift, fpst);
} else {
gen_helper_vfp_touls(tcg_res, tcg_single, tcg_shift, fpst);
}
neon_store_reg32(tcg_res, rd);
tcg_temp_free_i32(tcg_res);
tcg_temp_free_i32(tcg_single);
}
gen_helper_set_rmode(tcg_rmode, tcg_rmode, fpst);
tcg_temp_free_i32(tcg_rmode);
tcg_temp_free_i32(tcg_shift);
tcg_temp_free_ptr(fpst);
return true;
}
static bool trans_VMOV_to_gp(DisasContext *s, arg_VMOV_to_gp *a)
{
/* VMOV scalar to general purpose register */
TCGv_i32 tmp;
int pass;
uint32_t offset;
/* UNDEF accesses to D16-D31 if they don't exist */
if (!dc_isar_feature(aa32_fp_d32, s) && (a->vn & 0x10)) {
return false;
}
offset = a->index << a->size;
pass = extract32(offset, 2, 1);
offset = extract32(offset, 0, 2) * 8;
if (a->size != 2 && !arm_dc_feature(s, ARM_FEATURE_NEON)) {
return false;
}
if (!vfp_access_check(s)) {
return true;
}
tmp = neon_load_reg(a->vn, pass);
switch (a->size) {
case 0:
if (offset) {
tcg_gen_shri_i32(tmp, tmp, offset);
}
if (a->u) {
gen_uxtb(tmp);
} else {
gen_sxtb(tmp);
}
break;
case 1:
if (a->u) {
if (offset) {
tcg_gen_shri_i32(tmp, tmp, 16);
} else {
gen_uxth(tmp);
}
} else {
if (offset) {
tcg_gen_sari_i32(tmp, tmp, 16);
} else {
gen_sxth(tmp);
}
}
break;
case 2:
break;
}
store_reg(s, a->rt, tmp);
return true;
}
static bool trans_VMOV_from_gp(DisasContext *s, arg_VMOV_from_gp *a)
{
/* VMOV general purpose register to scalar */
TCGv_i32 tmp, tmp2;
int pass;
uint32_t offset;
/* UNDEF accesses to D16-D31 if they don't exist */
if (!dc_isar_feature(aa32_fp_d32, s) && (a->vn & 0x10)) {
return false;
}
offset = a->index << a->size;
pass = extract32(offset, 2, 1);
offset = extract32(offset, 0, 2) * 8;
if (a->size != 2 && !arm_dc_feature(s, ARM_FEATURE_NEON)) {
return false;
}
if (!vfp_access_check(s)) {
return true;
}
tmp = load_reg(s, a->rt);
switch (a->size) {
case 0:
tmp2 = neon_load_reg(a->vn, pass);
tcg_gen_deposit_i32(tmp, tmp2, tmp, offset, 8);
tcg_temp_free_i32(tmp2);
break;
case 1:
tmp2 = neon_load_reg(a->vn, pass);
tcg_gen_deposit_i32(tmp, tmp2, tmp, offset, 16);
tcg_temp_free_i32(tmp2);
break;
case 2:
break;
}
neon_store_reg(a->vn, pass, tmp);
return true;
}
static bool trans_VDUP(DisasContext *s, arg_VDUP *a)
{
/* VDUP (general purpose register) */
TCGv_i32 tmp;
int size, vec_size;
if (!arm_dc_feature(s, ARM_FEATURE_NEON)) {
return false;
}
/* UNDEF accesses to D16-D31 if they don't exist */
if (!dc_isar_feature(aa32_fp_d32, s) && (a->vn & 0x10)) {
return false;
}
if (a->b && a->e) {
return false;
}
if (a->q && (a->vn & 1)) {
return false;
}
vec_size = a->q ? 16 : 8;
if (a->b) {
size = 0;
} else if (a->e) {
size = 1;
} else {
size = 2;
}
if (!vfp_access_check(s)) {
return true;
}
tmp = load_reg(s, a->rt);
tcg_gen_gvec_dup_i32(size, neon_reg_offset(a->vn, 0),
vec_size, vec_size, tmp);
tcg_temp_free_i32(tmp);
return true;
}