s390x/tcg: Factor out conversion of softfloat exceptions

We want to reuse that function in vector instruction context. While at it,
cleanup the code, using defines for magic values and avoiding the
handcrafted bit conversion.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20190218122710.23639-4-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

diff --git a/target/s390x/fpu_helper.c b/target/s390x/fpu_helper.c
index 21236ca..de02cf7 100644 (file)
--- a/target/s390x/fpu_helper.c
+++ b/target/s390x/fpu_helper.c
@@ -36,10 +36,18 @@
 
 #define RET128(F) (env->retxl = F.low, F.high)
 
-#define convert_bit(mask, from, to) \
-    (to < from                      \
-     ? (mask / (from / to)) & to    \
-     : (mask & from) * (to / from))
+uint8_t s390_softfloat_exc_to_ieee(unsigned int exc)
+{
+    uint8_t s390_exc = 0;
+
+    s390_exc |= (exc & float_flag_invalid) ? S390_IEEE_MASK_INVALID : 0;
+    s390_exc |= (exc & float_flag_divbyzero) ? S390_IEEE_MASK_DIVBYZERO : 0;
+    s390_exc |= (exc & float_flag_overflow) ? S390_IEEE_MASK_OVERFLOW : 0;
+    s390_exc |= (exc & float_flag_underflow) ? S390_IEEE_MASK_UNDERFLOW : 0;
+    s390_exc |= (exc & float_flag_inexact) ? S390_IEEE_MASK_INEXACT : 0;
+
+    return s390_exc;
+}
 
 /* Should be called after any operation that may raise IEEE exceptions.  */
 static void handle_exceptions(CPUS390XState *env, uintptr_t retaddr)
@@ -53,14 +61,7 @@ static void handle_exceptions(CPUS390XState *env, uintptr_t retaddr)
         return;
     }
     env->fpu_status.float_exception_flags = 0;
-
-    /* Convert softfloat exception bits to s390 exception bits.  */
-    s390_exc = 0;
-    s390_exc |= convert_bit(qemu_exc, float_flag_invalid, 0x80);
-    s390_exc |= convert_bit(qemu_exc, float_flag_divbyzero, 0x40);
-    s390_exc |= convert_bit(qemu_exc, float_flag_overflow, 0x20);
-    s390_exc |= convert_bit(qemu_exc, float_flag_underflow, 0x10);
-    s390_exc |= convert_bit(qemu_exc, float_flag_inexact, 0x08);
+    s390_exc = s390_softfloat_exc_to_ieee(qemu_exc);
 
     /* Install the exceptions that we raised.  */
     env->fpc |= s390_exc << 16;

diff --git a/target/s390x/internal.h b/target/s390x/internal.h
index 9d0a45d..4db736b 100644 (file)
--- a/target/s390x/internal.h
+++ b/target/s390x/internal.h
@@ -311,6 +311,13 @@ void s390x_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
 uint32_t set_cc_nz_f32(float32 v);
 uint32_t set_cc_nz_f64(float64 v);
 uint32_t set_cc_nz_f128(float128 v);
+#define S390_IEEE_MASK_INVALID   0x80
+#define S390_IEEE_MASK_DIVBYZERO 0x40
+#define S390_IEEE_MASK_OVERFLOW  0x20
+#define S390_IEEE_MASK_UNDERFLOW 0x10
+#define S390_IEEE_MASK_INEXACT   0x08
+#define S390_IEEE_MASK_QUANTUM   0x04
+uint8_t s390_softfloat_exc_to_ieee(unsigned int exc);
 
 
 /* gdbstub.c */