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[Qemu-devel] [PATCH 2/5] target-arm: v6 media multiply space: UNDEF on u
From: |
Peter Maydell |
Subject: |
[Qemu-devel] [PATCH 2/5] target-arm: v6 media multiply space: UNDEF on unassigned encodings |
Date: |
Wed, 28 Sep 2011 18:27:30 +0100 |
Clean up the decoding of the v6 media multiply space so that we UNDEF
on unassigned encodings rather than randomly interpreting them as
some instruction in this space.
Signed-off-by: Peter Maydell <address@hidden>
---
target-arm/translate.c | 24 ++++++++++++++++++++----
1 files changed, 20 insertions(+), 4 deletions(-)
diff --git a/target-arm/translate.c b/target-arm/translate.c
index 75c0ad4..e99fc18 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -7569,11 +7569,16 @@ static void disas_arm_insn(CPUState * env, DisasContext
*s)
}
break;
case 2: /* Multiplies (Type 3). */
- tmp = load_reg(s, rm);
- tmp2 = load_reg(s, rs);
- if (insn & (1 << 20)) {
+ switch ((insn >> 20) & 0x7) {
+ case 5:
+ if (((insn >> 6) ^ (insn >> 7)) & 1) {
+ /* op2 not 00x or 11x : UNDEF */
+ goto illegal_op;
+ }
/* Signed multiply most significant [accumulate].
(SMMUL, SMMLA, SMMLS) */
+ tmp = load_reg(s, rm);
+ tmp2 = load_reg(s, rs);
tmp64 = gen_muls_i64_i32(tmp, tmp2);
if (rd != 15) {
@@ -7592,7 +7597,15 @@ static void disas_arm_insn(CPUState * env, DisasContext
*s)
tcg_gen_trunc_i64_i32(tmp, tmp64);
tcg_temp_free_i64(tmp64);
store_reg(s, rn, tmp);
- } else {
+ break;
+ case 0:
+ case 4:
+ /* SMLAD, SMUAD, SMLSD, SMUSD, SMLALD, SMLSLD */
+ if (insn & (1 << 7)) {
+ goto illegal_op;
+ }
+ tmp = load_reg(s, rm);
+ tmp2 = load_reg(s, rs);
if (insn & (1 << 5))
gen_swap_half(tmp2);
gen_smul_dual(tmp, tmp2);
@@ -7625,6 +7638,9 @@ static void disas_arm_insn(CPUState * env, DisasContext
*s)
}
store_reg(s, rn, tmp);
}
+ break;
+ default:
+ goto illegal_op;
}
break;
case 3:
--
1.7.1
- [Qemu-devel] [PATCH 0/5] target-arm: Implement UDIV/SDIV and fused multiply-accumulate, Peter Maydell, 2011/09/28
- [Qemu-devel] [PATCH 5/5] target-arm: Implement VFPv4 fused multiply-accumulate insns, Peter Maydell, 2011/09/28
- [Qemu-devel] [PATCH 3/5] target-arm: Add ARM UDIV/SDIV support, Peter Maydell, 2011/09/28
- [Qemu-devel] [PATCH 1/5] softfloat: Reinstate accidentally disabled target-specific NaN handling, Peter Maydell, 2011/09/28
- [Qemu-devel] [PATCH 2/5] target-arm: v6 media multiply space: UNDEF on unassigned encodings,
Peter Maydell <=
- [Qemu-devel] [PATCH 4/5] softfloat: Implement fused multiply-add, Peter Maydell, 2011/09/28
- Re: [Qemu-devel] [PATCH 0/5] target-arm: Implement UDIV/SDIV and fused multiply-accumulate, Blue Swirl, 2011/09/28