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target/arm: Fix neon VTBL/VTBX for len > 1 

The helper function did not get updated when we reorganized
the vector register file for SVE.  Since then, the neon dregs
are non-sequential and cannot be simply indexed.

At the same time, make the helper function operate on 64-bit
quantities so that we do not have to call it twice.

Fixes: c39c2b9043
Reported-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
[PMM: use aa32_vfp_dreg() rather than opencoding]
Message-id: 20201105171126.88014-1-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Richard Henderson 2020-11-05 09:11:26 -08:00 committed by Peter Maydell
parent bec3c97e0c
commit 604cef3e57
3 changed files with 29 additions and 40 deletions
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2
target/arm/helper.h
View File

@ -245,7 +245,7 @@ DEF_HELPER_FLAGS_2(rsqrte_f32, TCG_CALL_NO_RWG, f32, f32, ptr)
DEF_HELPER_FLAGS_2(rsqrte_f64, TCG_CALL_NO_RWG, f64, f64, ptr)
DEF_HELPER_FLAGS_1(recpe_u32, TCG_CALL_NO_RWG, i32, i32)
DEF_HELPER_FLAGS_1(rsqrte_u32, TCG_CALL_NO_RWG, i32, i32)
DEF_HELPER_FLAGS_4(neon_tbl, TCG_CALL_NO_RWG, i32, i32, i32, ptr, i32)
DEF_HELPER_FLAGS_4(neon_tbl, TCG_CALL_NO_RWG, i64, env, i32, i64, i64)
DEF_HELPER_3(shl_cc, i32, env, i32, i32)
DEF_HELPER_3(shr_cc, i32, env, i32, i32)

23
target/arm/op_helper.c
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@ -68,21 +68,24 @@ void raise_exception_ra(CPUARMState *env, uint32_t excp, uint32_t syndrome,
cpu_loop_exit_restore(cs, ra);
}
uint32_t HELPER(neon_tbl)(uint32_t ireg, uint32_t def, void *vn,
uint32_t maxindex)
uint64_t HELPER(neon_tbl)(CPUARMState *env, uint32_t desc,
uint64_t ireg, uint64_t def)
{
uint32_t val, shift;
uint64_t *table = vn;
uint64_t tmp, val = 0;
uint32_t maxindex = ((desc & 3) + 1) * 8;
uint32_t base_reg = desc >> 2;
uint32_t shift, index, reg;
val = 0;
for (shift = 0; shift < 32; shift += 8) {
uint32_t index = (ireg >> shift) & 0xff;
for (shift = 0; shift < 64; shift += 8) {
index = (ireg >> shift) & 0xff;
if (index < maxindex) {
uint32_t tmp = (table[index >> 3] >> ((index & 7) << 3)) & 0xff;
val |= tmp << shift;
reg = base_reg + (index >> 3);
tmp = *aa32_vfp_dreg(env, reg);
tmp = ((tmp >> ((index & 7) << 3)) & 0xff) << shift;
} else {
val |= def & (0xff << shift);
tmp = def & (0xffull << shift);
}
val |= tmp;
}
return val;
}

44
target/arm/translate-neon.c.inc
View File

@ -2861,9 +2861,8 @@ static bool trans_VEXT(DisasContext *s, arg_VEXT *a)
static bool trans_VTBL(DisasContext *s, arg_VTBL *a)
{
int n;
TCGv_i32 tmp, tmp2, tmp3, tmp4;
TCGv_ptr ptr1;
TCGv_i64 val, def;
TCGv_i32 desc;
if (!arm_dc_feature(s, ARM_FEATURE_NEON)) {
return false;
@ -2879,43 +2878,30 @@ static bool trans_VTBL(DisasContext *s, arg_VTBL *a)
return true;
}
n = a->len + 1;
if ((a->vn + n) > 32) {
if ((a->vn + a->len + 1) > 32) {
/*
* This is UNPREDICTABLE; we choose to UNDEF to avoid the
* helper function running off the end of the register file.
*/
return false;
}
n <<= 3;
tmp = tcg_temp_new_i32();
if (a->op) {
read_neon_element32(tmp, a->vd, 0, MO_32);
} else {
tcg_gen_movi_i32(tmp, 0);
}
tmp2 = tcg_temp_new_i32();
read_neon_element32(tmp2, a->vm, 0, MO_32);
ptr1 = vfp_reg_ptr(true, a->vn);
tmp4 = tcg_const_i32(n);
gen_helper_neon_tbl(tmp2, tmp2, tmp, ptr1, tmp4);
desc = tcg_const_i32((a->vn << 2) | a->len);
def = tcg_temp_new_i64();
if (a->op) {
read_neon_element32(tmp, a->vd, 1, MO_32);
read_neon_element64(def, a->vd, 0, MO_64);
} else {
tcg_gen_movi_i32(tmp, 0);
tcg_gen_movi_i64(def, 0);
}
tmp3 = tcg_temp_new_i32();
read_neon_element32(tmp3, a->vm, 1, MO_32);
gen_helper_neon_tbl(tmp3, tmp3, tmp, ptr1, tmp4);
tcg_temp_free_i32(tmp);
tcg_temp_free_i32(tmp4);
tcg_temp_free_ptr(ptr1);
val = tcg_temp_new_i64();
read_neon_element64(val, a->vm, 0, MO_64);
write_neon_element32(tmp2, a->vd, 0, MO_32);
write_neon_element32(tmp3, a->vd, 1, MO_32);
tcg_temp_free_i32(tmp2);
tcg_temp_free_i32(tmp3);
gen_helper_neon_tbl(val, cpu_env, desc, val, def);
write_neon_element64(val, a->vd, 0, MO_64);
tcg_temp_free_i64(def);
tcg_temp_free_i64(val);
tcg_temp_free_i32(desc);
return true;
}