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target/arm/translate-a64: Don't underdecode FP insns

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In the encoding groups
 * floating-point data-processing (1 source)
 * floating-point data-processing (2 source)
 * floating-point data-processing (3 source)
 * floating-point immediate
 * floating-point compare
 * floating-ponit conditional compare
 * floating-point conditional select

bit 31 is M and bit 29 is S (and bit 30 is 0, already checked at
this point in the decode). None of these groups allocate any
encoding for M=1 or S=1. We checked this in disas_fp_compare(),
disas_fp_ccomp() and disas_fp_csel(), but missed it in disas_fp_1src(),
disas_fp_2src(), disas_fp_3src() and disas_fp_imm().

We also missed that in the fp immediate encoding the imm5 field
must be all zeroes.

Correctly UNDEF the unallocated encodings here.

Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Laurent Desnogues <laurent.desnogues@gmail.com>
Message-id: 20190125182626.9221-7-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2019-02-01 14:55:45 +00:00
parent 4f61106614
commit c1e20801f5
1 changed files with 21 additions and 1 deletions
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22
target/arm/translate-a64.c
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@ -5636,11 +5636,17 @@ static void handle_fp_fcvt(DisasContext *s, int opcode,
*/
static void disas_fp_1src(DisasContext *s, uint32_t insn)
{
int mos = extract32(insn, 29, 3);
int type = extract32(insn, 22, 2);
int opcode = extract32(insn, 15, 6);
int rn = extract32(insn, 5, 5);
int rd = extract32(insn, 0, 5);
if (mos) {
unallocated_encoding(s);
return;
}
switch (opcode) {
case 0x4: case 0x5: case 0x7:
{
@ -5867,13 +5873,14 @@ static void handle_fp_2src_half(DisasContext *s, int opcode,
*/
static void disas_fp_2src(DisasContext *s, uint32_t insn)
{
int mos = extract32(insn, 29, 3);
int type = extract32(insn, 22, 2);
int rd = extract32(insn, 0, 5);
int rn = extract32(insn, 5, 5);
int rm = extract32(insn, 16, 5);
int opcode = extract32(insn, 12, 4);
if (opcode > 8) {
if (opcode > 8 || mos) {
unallocated_encoding(s);
return;
}
@ -6028,6 +6035,7 @@ static void handle_fp_3src_half(DisasContext *s, bool o0, bool o1,
*/
static void disas_fp_3src(DisasContext *s, uint32_t insn)
{
int mos = extract32(insn, 29, 3);
int type = extract32(insn, 22, 2);
int rd = extract32(insn, 0, 5);
int rn = extract32(insn, 5, 5);
@ -6036,6 +6044,11 @@ static void disas_fp_3src(DisasContext *s, uint32_t insn)
bool o0 = extract32(insn, 15, 1);
bool o1 = extract32(insn, 21, 1);
if (mos) {
unallocated_encoding(s);
return;
}
switch (type) {
case 0:
if (!fp_access_check(s)) {
@ -6105,12 +6118,19 @@ uint64_t vfp_expand_imm(int size, uint8_t imm8)
static void disas_fp_imm(DisasContext *s, uint32_t insn)
{
int rd = extract32(insn, 0, 5);
int imm5 = extract32(insn, 5, 5);
int imm8 = extract32(insn, 13, 8);
int type = extract32(insn, 22, 2);
int mos = extract32(insn, 29, 3);
uint64_t imm;
TCGv_i64 tcg_res;
TCGMemOp sz;
if (mos || imm5) {
unallocated_encoding(s);
return;
}
switch (type) {
case 0:
sz = MO_32;