[Qemu-devel] [PATCH v2 18/22] target-mips: do not allow Status.FR=0 mode in 64-bit FPU

[Leon Alrae <leon.alrae@imgtec.com>]

Status.FR bit must be ignored on write and read as 1 when an implementation of
Release 6 of the Architecture in which a 64-bit floating point unit is
implemented.

Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
---
 target-mips/translate.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/target-mips/translate.c b/target-mips/translate.c
index 4c75006..e635999 100644
--- a/target-mips/translate.c
+++ b/target-mips/translate.c
@@ -17899,6 +17899,13 @@ void cpu_state_reset(CPUMIPSState *env)
         }
     }
 #endif
+    if ((env->insn_flags & ISA_MIPS32R6) &&
+        (env->active_fpu.fcr0 & (1 << FCR0_F64))) {
+        /* Status.FR = 0 mode in 64-bit FPU not allowed in R6 */
+        env->CP0_Status |= (1 << CP0St_FR);
+        env->CP0_Status_rw_bitmask &= ~(1 << CP0St_FR);
+    }
+
     compute_hflags(env);
     cs->exception_index = EXCP_NONE;
 }
-- 
1.7.5.4