[RESEND] target/ppc: Fix bugs in VSX_CVT_FP_TO_INT and VSX_CVT_FP_TO_INT2 macros

Commit Message

John Platts Nov. 1, 2023, 1:17 p.m. UTC

The patch below fixes a bug in the VSX_CVT_FP_TO_INT and VSX_CVT_FP_TO_INT2 
macros in target/ppc/fpu_helper.c where a non-NaN floating point value from the 
source vector is incorrectly converted to 0, 0x80000000, or 0x8000000000000000 
instead of the expected value if a preceding source floating point value from 
the same source vector was a NaN.

The bug in the VSX_CVT_FP_TO_INT and VSX_CVT_FP_TO_INT2 macros in 
target/ppc/fpu_helper.c was introduced with commit c3f24257.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1941
Signed-off-by: John Platts <[e-mail]>

---
 target/ppc/fpu_helper.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

Patch

diff --git a/target/ppc/fpu_helper.c b/target/ppc/fpu_helper.c
index 03150a0f10..d6c8583416 100644
--- a/target/ppc/fpu_helper.c
+++ b/target/ppc/fpu_helper.c
@@ -2880,19 +2880,21 @@  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 = 0;                                                       \
     ppc_vsr_t t = { };                                                       \
     int i, flags;                                                            \
                                                                              \
-    helper_reset_fpstatus(env);                                              \
-                                                                             \
     for (i = 0; i < nels; i++) {                                             \
+        helper_reset_fpstatus(env);                                          \
         t.tfld = stp##_to_##ttp##_round_to_zero(xb->sfld, &env->fp_status);  \
         flags = env->fp_status.float_exception_flags;                        \
+        all_flags |= flags;                                                  \
         if (unlikely(flags & float_flag_invalid)) {                          \
             t.tfld = float_invalid_cvt(env, flags, t.tfld, rnan, 0, GETPC());\
         }                                                                    \
     }                                                                        \
                                                                              \
+    env->fp_status.float_exception_flags = all_flags;                        \
     *xt = t;                                                                 \
     do_float_check_status(env, sfi, GETPC());                                \
 }
@@ -2945,15 +2947,16 @@  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 = 0;                                                       \
     ppc_vsr_t t = { };                                                       \
     int i, flags;                                                            \
                                                                              \
-    helper_reset_fpstatus(env);                                              \
-                                                                             \
     for (i = 0; i < nels; i++) {                                             \
+        helper_reset_fpstatus(env);                                          \
         t.VsrW(2 * i) = stp##_to_##ttp##_round_to_zero(xb->VsrD(i),          \
                                                        &env->fp_status);     \
         flags = env->fp_status.float_exception_flags;                        \
+        all_flags |= flags;                                                  \
         if (unlikely(flags & float_flag_invalid)) {                          \
             t.VsrW(2 * i) = float_invalid_cvt(env, flags, t.VsrW(2 * i),     \
                                               rnan, 0, GETPC());             \
@@ -2961,6 +2964,7 @@  void helper_##op(CPUPPCState *env, ppc_vsr_t *xt, ppc_vsr_t *xb)             \
         t.VsrW(2 * i + 1) = t.VsrW(2 * i);                                   \
     }                                                                        \
                                                                              \
+    env->fp_status.float_exception_flags = all_flags;                        \
     *xt = t;                                                                 \
     do_float_check_status(env, sfi, GETPC());                                \
 }