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[Qemu-devel] [PATCH 2/3] target-arm: UNDEF on a VCVTT/VCVTB UNPREDICTABL
From: |
Peter Maydell |
Subject: |
[Qemu-devel] [PATCH 2/3] target-arm: UNDEF on a VCVTT/VCVTB UNPREDICTABLE to avoid TCG assert |
Date: |
Fri, 22 Jul 2011 11:51:20 +0100 |
VCVTT/VCVTB with bit 8 set is UNPREDICTABLE; we choose to UNDEF.
This avoids a TCG assert later when the VCVTT/VCVTB code tries to
use a source register that wasn't ever set up.
We pull the check for the presence of the half-precision extension
up in to this common code as well.
Signed-off-by: Peter Maydell <address@hidden>
---
target-arm/translate.c | 19 +++++++++++--------
1 files changed, 11 insertions(+), 8 deletions(-)
diff --git a/target-arm/translate.c b/target-arm/translate.c
index 7bce343..a9a70e5 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -3056,6 +3056,17 @@ static int disas_vfp_insn(CPUState * env, DisasContext
*s, uint32_t insn)
/* Source and destination the same. */
gen_mov_F0_vreg(dp, rd);
break;
+ case 4:
+ case 5:
+ case 6:
+ case 7:
+ /* VCVTB, VCVTT: only present with the halfprec extension,
+ * UNPREDICTABLE if bit 8 is set (we choose to UNDEF)
+ */
+ if (dp || !arm_feature(env, ARM_FEATURE_VFP_FP16)) {
+ return 1;
+ }
+ /* Otherwise fall through */
default:
/* One source operand. */
gen_mov_F0_vreg(dp, rm);
@@ -3152,24 +3163,18 @@ static int disas_vfp_insn(CPUState * env, DisasContext
*s, uint32_t insn)
gen_vfp_sqrt(dp);
break;
case 4: /* vcvtb.f32.f16 */
- if (!arm_feature(env, ARM_FEATURE_VFP_FP16))
- return 1;
tmp = gen_vfp_mrs();
tcg_gen_ext16u_i32(tmp, tmp);
gen_helper_vfp_fcvt_f16_to_f32(cpu_F0s, tmp, cpu_env);
tcg_temp_free_i32(tmp);
break;
case 5: /* vcvtt.f32.f16 */
- if (!arm_feature(env, ARM_FEATURE_VFP_FP16))
- return 1;
tmp = gen_vfp_mrs();
tcg_gen_shri_i32(tmp, tmp, 16);
gen_helper_vfp_fcvt_f16_to_f32(cpu_F0s, tmp, cpu_env);
tcg_temp_free_i32(tmp);
break;
case 6: /* vcvtb.f16.f32 */
- if (!arm_feature(env, ARM_FEATURE_VFP_FP16))
- return 1;
tmp = tcg_temp_new_i32();
gen_helper_vfp_fcvt_f32_to_f16(tmp, cpu_F0s, cpu_env);
gen_mov_F0_vreg(0, rd);
@@ -3180,8 +3185,6 @@ static int disas_vfp_insn(CPUState * env, DisasContext
*s, uint32_t insn)
gen_vfp_msr(tmp);
break;
case 7: /* vcvtt.f16.f32 */
- if (!arm_feature(env, ARM_FEATURE_VFP_FP16))
- return 1;
tmp = tcg_temp_new_i32();
gen_helper_vfp_fcvt_f32_to_f16(tmp, cpu_F0s, cpu_env);
tcg_gen_shli_i32(tmp, tmp, 16);
--
1.7.1