[Qemu-devel] [PATCH 14/18] target-ppc: Fix and enable fri[mnpz]

[Tom Musta <tommusta@gmail.com>]

The fri* series of instructions was introduced prior to ISA 2.06 and
is supported on Power7 and Power8 hardware.  However, the instruction
is still considered illegal in the P7 and P8 QEMU emulation models.
This patch enables these instructions for the P7 and P8 machines.

Also, the existing helper is modified to correctly handle some of
the boundary cases (NaNs and the inexact flag).

Signed-off-by: Tom Musta <tommusta@gmail.com>
---
 target-ppc/fpu_helper.c     |   12 ++++++------
 target-ppc/translate_init.c |    2 ++
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/target-ppc/fpu_helper.c b/target-ppc/fpu_helper.c
index 5521fc2..1fb3d15 100644
--- a/target-ppc/fpu_helper.c
+++ b/target-ppc/fpu_helper.c
@@ -668,18 +668,18 @@ static inline uint64_t do_fri(CPUPPCState *env, uint64_t arg,
 
     if (unlikely(float64_is_signaling_nan(farg.d))) {
         /* sNaN round */
-        farg.ll = fload_invalid_op_excp(env, POWERPC_EXCP_FP_VXSNAN |
-                                        POWERPC_EXCP_FP_VXCVI, 1);
-    } else if (unlikely(float64_is_quiet_nan(farg.d) ||
-                        float64_is_infinity(farg.d))) {
-        /* qNan / infinity round */
-        farg.ll = fload_invalid_op_excp(env, POWERPC_EXCP_FP_VXCVI, 1);
+        fload_invalid_op_excp(env, POWERPC_EXCP_FP_VXSNAN, 1);
+        farg.ll = float64_default_nan | 0x0008000000000000ul;
     } else {
         set_float_rounding_mode(rounding_mode, &env->fp_status);
         farg.ll = float64_round_to_int(farg.d, &env->fp_status);
         /* Restore rounding mode from FPSCR */
         fpscr_set_rounding_mode(env);
+
+        /* fri* does not set FPSCR[XX] */
+        env->fp_status.float_exception_flags &= ~float_flag_inexact;
     }
+    helper_float_check_status(env);
     return farg.ll;
 }
 
diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
index 491e56c..7bb9bbc 100644
--- a/target-ppc/translate_init.c
+++ b/target-ppc/translate_init.c
@@ -7228,6 +7228,7 @@ POWERPC_FAMILY(POWER7)(ObjectClass *oc, void *data)
                        PPC_FLOAT | PPC_FLOAT_FSEL | PPC_FLOAT_FRES |
                        PPC_FLOAT_FSQRT | PPC_FLOAT_FRSQRTE |
                        PPC_FLOAT_STFIWX |
+                       PPC_FLOAT_EXT |
                        PPC_CACHE | PPC_CACHE_ICBI | PPC_CACHE_DCBZ |
                        PPC_MEM_SYNC | PPC_MEM_EIEIO |
                        PPC_MEM_TLBIE | PPC_MEM_TLBSYNC |
@@ -7265,6 +7266,7 @@ POWERPC_FAMILY(POWER8)(ObjectClass *oc, void *data)
                        PPC_FLOAT | PPC_FLOAT_FSEL | PPC_FLOAT_FRES |
                        PPC_FLOAT_FSQRT | PPC_FLOAT_FRSQRTE |
                        PPC_FLOAT_STFIWX |
+                       PPC_FLOAT_EXT |
                        PPC_CACHE | PPC_CACHE_ICBI | PPC_CACHE_DCBZ |
                        PPC_MEM_SYNC | PPC_MEM_EIEIO |
                        PPC_MEM_TLBIE | PPC_MEM_TLBSYNC |
-- 
1.7.1