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-rw-r--r--target/arm/helper.c53
1 files changed, 51 insertions, 2 deletions
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 0fef5d4d06..817f9d81a0 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -11420,11 +11420,60 @@ VFP_CONV_FIX_A64(sq, s, 32, 64, int64)
VFP_CONV_FIX(uh, s, 32, 32, uint16)
VFP_CONV_FIX(ul, s, 32, 32, uint32)
VFP_CONV_FIX_A64(uq, s, 32, 64, uint64)
-VFP_CONV_FIX_A64(sl, h, 16, 32, int32)
-VFP_CONV_FIX_A64(ul, h, 16, 32, uint32)
+
#undef VFP_CONV_FIX
#undef VFP_CONV_FIX_FLOAT
#undef VFP_CONV_FLOAT_FIX_ROUND
+#undef VFP_CONV_FIX_A64
+
+/* Conversion to/from f16 can overflow to infinity before/after scaling.
+ * Therefore we convert to f64 (which does not round), scale,
+ * and then convert f64 to f16 (which may round).
+ */
+
+static float16 do_postscale_fp16(float64 f, int shift, float_status *fpst)
+{
+ return float64_to_float16(float64_scalbn(f, -shift, fpst), true, fpst);
+}
+
+float16 HELPER(vfp_sltoh)(uint32_t x, uint32_t shift, void *fpst)
+{
+ return do_postscale_fp16(int32_to_float64(x, fpst), shift, fpst);
+}
+
+float16 HELPER(vfp_ultoh)(uint32_t x, uint32_t shift, void *fpst)
+{
+ return do_postscale_fp16(uint32_to_float64(x, fpst), shift, fpst);
+}
+
+static float64 do_prescale_fp16(float16 f, int shift, float_status *fpst)
+{
+ if (unlikely(float16_is_any_nan(f))) {
+ float_raise(float_flag_invalid, fpst);
+ return 0;
+ } else {
+ int old_exc_flags = get_float_exception_flags(fpst);
+ float64 ret;
+
+ ret = float16_to_float64(f, true, fpst);
+ ret = float64_scalbn(ret, shift, fpst);
+ old_exc_flags |= get_float_exception_flags(fpst)
+ & float_flag_input_denormal;
+ set_float_exception_flags(old_exc_flags, fpst);
+
+ return ret;
+ }
+}
+
+uint32_t HELPER(vfp_toshh)(float16 x, uint32_t shift, void *fpst)
+{
+ return float64_to_int16(do_prescale_fp16(x, shift, fpst), fpst);
+}
+
+uint32_t HELPER(vfp_touhh)(float16 x, uint32_t shift, void *fpst)
+{
+ return float64_to_uint16(do_prescale_fp16(x, shift, fpst), fpst);
+}
/* Set the current fp rounding mode and return the old one.
* The argument is a softfloat float_round_ value.