[Qemu-devel] [PATCH] FMULX should flushes operators to zero when FZ is set.

[Xiangyu Hu <libhu.so@gmail.com>]

The difference between FMULX and FMUL is that FMULX will return 2.0f when one operator is 
FPInfinity and the other one is FPZero, whilst FMUL will return a Default NaN. Without 
this patch, the emulation would result in inconsistency.

Signed-off-by: Xiangyu Hu <libhu.so@gmail.com>
---
 target-arm/helper-a64.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/target-arm/helper-a64.c b/target-arm/helper-a64.c
index 81066ca..ebd9247 100644
--- a/target-arm/helper-a64.c
+++ b/target-arm/helper-a64.c
@@ -135,6 +135,9 @@ float32 HELPER(vfp_mulxs)(float32 a, float32 b, void *fpstp)
 {
     float_status *fpst = fpstp;
 
+    a = float32_squash_input_denormal(a, fpst);
+    b = float32_squash_input_denormal(b, fpst);
+
     if ((float32_is_zero(a) && float32_is_infinity(b)) ||
         (float32_is_infinity(a) && float32_is_zero(b))) {
         /* 2.0 with the sign bit set to sign(A) XOR sign(B) */
@@ -148,6 +151,9 @@ float64 HELPER(vfp_mulxd)(float64 a, float64 b, void *fpstp)
 {
     float_status *fpst = fpstp;
 
+    a = float64_squash_input_denormal(a, fpst);
+    b = float64_squash_input_denormal(b, fpst);
+
     if ((float64_is_zero(a) && float64_is_infinity(b)) ||
         (float64_is_infinity(a) && float64_is_zero(b))) {
         /* 2.0 with the sign bit set to sign(A) XOR sign(B) */
-- 
1.9.1