diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2011-04-11 16:26:16 +0100 |
|---|---|---|
| committer | Aurelien Jarno <aurelien@aurel32.net> | 2011-04-12 23:33:33 +0200 |
| commit | 7d80fee5b9e663148ddee714e3b755a0af20508d (patch) | |
| tree | 7c31083d359d57188eae5c77bfb00f3ecd945973 /target-arm | |
| parent | 2bc70834e867e7a0c4f30d374405acf8d81bba03 (diff) | |
target-arm: Handle UNDEF cases for Neon invalid modified-immediates
For Neon "one register and a modified immediate value" forms, the
combination op=1 cmode=1111 is unallocated and should UNDEF.
All instructions of this form also UNDEF if Q == 1 and Vd<0> == 1.
We also add a comment on the only UNPREDICTABLE in this space.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Diffstat (limited to 'target-arm')
| -rw-r--r-- | target-arm/translate.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/target-arm/translate.c b/target-arm/translate.c index a86c54c564..0a9b3cf354 100644 --- a/target-arm/translate.c +++ b/target-arm/translate.c @@ -5084,11 +5084,18 @@ static int disas_neon_data_insn(CPUState * env, DisasContext *s, uint32_t insn) } } else { /* (insn & 0x00380080) == 0 */ int invert; + if (q && (rd & 1)) { + return 1; + } op = (insn >> 8) & 0xf; /* One register and immediate. */ imm = (u << 7) | ((insn >> 12) & 0x70) | (insn & 0xf); invert = (insn & (1 << 5)) != 0; + /* Note that op = 2,3,4,5,6,7,10,11,12,13 imm=0 is UNPREDICTABLE. + * We choose to not special-case this and will behave as if a + * valid constant encoding of 0 had been given. + */ switch (op) { case 0: case 1: /* no-op */ @@ -5120,6 +5127,9 @@ static int disas_neon_data_insn(CPUState * env, DisasContext *s, uint32_t insn) imm = ~imm; break; case 15: + if (invert) { + return 1; + } imm = ((imm & 0x80) << 24) | ((imm & 0x3f) << 19) | ((imm & 0x40) ? (0x1f << 25) : (1 << 30)); break; |