target/ppc: Clear fpstatus flags on helpers missing it

In ppc emulation, exception flags are not cleared at the end of an
instruction. Instead, the next instruction is responsible to clear
it before its emulation. However, some helpers are not doing it,
causing an issue where the previously set exception flags are being
used and leading to incorrect values being set in FPSCR.
Fix this by clearing fp_status before doing the instruction 'real' work
for the following helpers that were missing this behavior:

- VSX_CVT_INT_TO_FP_VECTOR
- VSX_CVT_FP_TO_FP
- VSX_CVT_FP_TO_INT_VECTOR
- VSX_CVT_FP_TO_INT2
- VSX_CVT_FP_TO_INT
- VSX_CVT_FP_TO_FP_HP
- VSX_CVT_FP_TO_FP_VECTOR
- VSX_CMP
- VSX_ROUND
- xscvqpdp
- xscvdpsp[n]

Signed-off-by: Víctor Colombo <victor.colombo@eldorado.org.br>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220906125523.38765-9-victor.colombo@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

1 files changed, 26 insertions, 11 deletions

diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c
index f07330f..ae25f32 100644
--- a/target/ppc/fpu_helper.c
+++ b/target/ppc/fpu_helper.c
@@ -2628,6 +2628,8 @@ uint32_t helper_##op(CPUPPCState *env, ppc_vsr_t *xt,                     \
     int all_true = 1;                                                     \
     int all_false = 1;                                                    \
                                                                           \
+    helper_reset_fpstatus(env);                                           \
+                                                                          \
     for (i = 0; i < nels; i++) {                                          \
         if (unlikely(tp##_is_any_nan(xa->fld) ||                          \
                      tp##_is_any_nan(xb->fld))) {                         \
@@ -2681,6 +2683,8 @@ void helper_##op(CPUPPCState *env, ppc_vsr_t *xt, ppc_vsr_t *xb)   \
     ppc_vsr_t t = { };                                             \
     int i;                                                         \
                                                                    \
+    helper_reset_fpstatus(env);                                    \
+                                                                   \
     for (i = 0; i < nels; i++) {                                   \
         t.tfld = stp##_to_##ttp(xb->sfld, &env->fp_status);        \
         if (unlikely(stp##_is_signaling_nan(xb->sfld,              \
@@ -2706,6 +2710,8 @@ void helper_##op(CPUPPCState *env, ppc_vsr_t *xt, ppc_vsr_t *xb)      \
     ppc_vsr_t t = { };                                                \
     int i;                                                            \
                                                                       \
+    helper_reset_fpstatus(env);                                       \
+                                                                      \
     for (i = 0; i < nels; i++) {                                      \
         t.VsrW(2 * i) = stp##_to_##ttp(xb->VsrD(i), &env->fp_status); \
         if (unlikely(stp##_is_signaling_nan(xb->VsrD(i),              \
@@ -2743,6 +2749,8 @@ void helper_##op(CPUPPCState *env, uint32_t opcode,                     \
     ppc_vsr_t t = *xt;                                                  \
     int i;                                                              \
                                                                         \
+    helper_reset_fpstatus(env);                                         \
+                                                                        \
     for (i = 0; i < nels; i++) {                                        \
         t.tfld = stp##_to_##ttp(xb->sfld, &env->fp_status);             \
         if (unlikely(stp##_is_signaling_nan(xb->sfld,                   \
@@ -2778,6 +2786,8 @@ void helper_##op(CPUPPCState *env, ppc_vsr_t *xt, ppc_vsr_t *xb)   \
     ppc_vsr_t t = { };                                             \
     int i;                                                         \
                                                                    \
+    helper_reset_fpstatus(env);                                    \
+                                                                   \
     for (i = 0; i < nels; i++) {                                   \
         t.tfld = stp##_to_##ttp(xb->sfld, 1, &env->fp_status);     \
         if (unlikely(stp##_is_signaling_nan(xb->sfld,              \
@@ -2825,6 +2835,8 @@ void helper_XSCVQPDP(CPUPPCState *env, uint32_t ro, ppc_vsr_t *xt,
     ppc_vsr_t t = { };
     float_status tstat;
 
+    helper_reset_fpstatus(env);
+
     tstat = env->fp_status;
     if (ro != 0) {
         tstat.float_rounding_mode = float_round_to_odd;
@@ -2846,6 +2858,7 @@ uint64_t helper_xscvdpspn(CPUPPCState *env, uint64_t xb)
 {
     uint64_t result, sign, exp, frac;
 
+    helper_reset_fpstatus(env);
     float_status tstat = env->fp_status;
     set_float_exception_flags(0, &tstat);
 
@@ -2901,22 +2914,20 @@ uint64_t helper_XSCVSPDPN(uint64_t xb)
 #define VSX_CVT_FP_TO_INT(op, nels, stp, ttp, sfld, tfld, sfi, rnan)         \
 void helper_##op(CPUPPCState *env, ppc_vsr_t *xt, ppc_vsr_t *xb)             \
 {                                                                            \
-    int all_flags = env->fp_status.float_exception_flags, flags;             \
     ppc_vsr_t t = { };                                                       \
-    int i;                                                                   \
+    int i, flags;                                                            \
+                                                                             \
+    helper_reset_fpstatus(env);                                              \
                                                                              \
     for (i = 0; i < nels; i++) {                                             \
-        env->fp_status.float_exception_flags = 0;                            \
         t.tfld = stp##_to_##ttp##_round_to_zero(xb->sfld, &env->fp_status);  \
         flags = env->fp_status.float_exception_flags;                        \
         if (unlikely(flags & float_flag_invalid)) {                          \
             t.tfld = float_invalid_cvt(env, flags, t.tfld, rnan, 0, GETPC());\
         }                                                                    \
-        all_flags |= flags;                                                  \
     }                                                                        \
                                                                              \
     *xt = t;                                                                 \
-    env->fp_status.float_exception_flags = all_flags;                        \
     do_float_check_status(env, sfi, GETPC());                                \
 }
 
@@ -2968,12 +2979,12 @@ VSX_CVT_FP_TO_INT128(XSCVQPSQZ, int128, 0x8000000000000000ULL);
 #define VSX_CVT_FP_TO_INT2(op, nels, stp, ttp, sfi, rnan)                    \
 void helper_##op(CPUPPCState *env, ppc_vsr_t *xt, ppc_vsr_t *xb)             \
 {                                                                            \
-    int all_flags = env->fp_status.float_exception_flags, flags;             \
     ppc_vsr_t t = { };                                                       \
-    int i;                                                                   \
+    int i, flags;                                                            \
+                                                                             \
+    helper_reset_fpstatus(env);                                              \
                                                                              \
     for (i = 0; i < nels; i++) {                                             \
-        env->fp_status.float_exception_flags = 0;                            \
         t.VsrW(2 * i) = stp##_to_##ttp##_round_to_zero(xb->VsrD(i),          \
                                                        &env->fp_status);     \
         flags = env->fp_status.float_exception_flags;                        \
@@ -2982,11 +2993,9 @@ void helper_##op(CPUPPCState *env, ppc_vsr_t *xt, ppc_vsr_t *xb)             \
                                               rnan, 0, GETPC());             \
         }                                                                    \
         t.VsrW(2 * i + 1) = t.VsrW(2 * i);                                   \
-        all_flags |= flags;                                                  \
     }                                                                        \
                                                                              \
     *xt = t;                                                                 \
-    env->fp_status.float_exception_flags = all_flags;                        \
     do_float_check_status(env, sfi, GETPC());                                \
 }
 
@@ -3011,6 +3020,8 @@ void helper_##op(CPUPPCState *env, uint32_t opcode,                          \
     ppc_vsr_t t = { };                                                       \
     int flags;                                                               \
                                                                              \
+    helper_reset_fpstatus(env);                                              \
+                                                                             \
     t.tfld = stp##_to_##ttp##_round_to_zero(xb->sfld, &env->fp_status);      \
     flags = get_float_exception_flags(&env->fp_status);                      \
     if (flags & float_flag_invalid) {                                        \
@@ -3023,7 +3034,6 @@ void helper_##op(CPUPPCState *env, uint32_t opcode,                          \
 
 VSX_CVT_FP_TO_INT_VECTOR(xscvqpsdz, float128, int64, f128, VsrD(0),          \
                   0x8000000000000000ULL)
-
 VSX_CVT_FP_TO_INT_VECTOR(xscvqpswz, float128, int32, f128, VsrD(0),          \
                   0xffffffff80000000ULL)
 VSX_CVT_FP_TO_INT_VECTOR(xscvqpudz, float128, uint64, f128, VsrD(0), 0x0ULL)
@@ -3046,6 +3056,8 @@ void helper_##op(CPUPPCState *env, ppc_vsr_t *xt, ppc_vsr_t *xb)        \
     ppc_vsr_t t = { };                                                  \
     int i;                                                              \
                                                                         \
+    helper_reset_fpstatus(env);                                         \
+                                                                        \
     for (i = 0; i < nels; i++) {                                        \
         t.tfld = stp##_to_##ttp(xb->sfld, &env->fp_status);             \
         if (r2sp) {                                                     \
@@ -3115,6 +3127,7 @@ void helper_##op(CPUPPCState *env, uint32_t opcode,                     \
 {                                                                       \
     ppc_vsr_t t = *xt;                                                  \
                                                                         \
+    helper_reset_fpstatus(env);                                         \
     t.tfld = stp##_to_##ttp(xb->sfld, &env->fp_status);                 \
     helper_compute_fprf_##ttp(env, t.tfld);                             \
                                                                         \
@@ -3148,6 +3161,8 @@ void helper_##op(CPUPPCState *env, ppc_vsr_t *xt, ppc_vsr_t *xb)       \
     int i;                                                             \
     FloatRoundMode curr_rounding_mode;                                 \
                                                                        \
+    helper_reset_fpstatus(env);                                        \
+                                                                       \
     if (rmode != FLOAT_ROUND_CURRENT) {                                \
         curr_rounding_mode = get_float_rounding_mode(&env->fp_status); \
         set_float_rounding_mode(rmode, &env->fp_status);               \