@@ -3559,6 +3559,13 @@ float32 int64_to_float32_scalbn(int64_t a, int scale, float_status *status)
{
FloatParts64 p;
+ /* Without scaling, there are no overflow concerns. */
+ if (likely(scale == 0) && can_use_fpu(status)) {
+ union_float32 ur;
+ ur.h = a;
+ return ur.s;
+ }
+
parts64_sint_to_float(&p, a, scale, status);
return float32_round_pack_canonical(&p, status);
}
@@ -3592,6 +3599,13 @@ float64 int64_to_float64_scalbn(int64_t a, int scale, float_status *status)
{
FloatParts64 p;
+ /* Without scaling, there are no overflow concerns. */
+ if (likely(scale == 0) && can_use_fpu(status)) {
+ union_float64 ur;
+ ur.h = a;
+ return ur.s;
+ }
+
parts_sint_to_float(&p, a, scale, status);
return float64_round_pack_canonical(&p, status);
}
@@ -3726,6 +3740,13 @@ float32 uint64_to_float32_scalbn(uint64_t a, int scale, float_status *status)
{
FloatParts64 p;
+ /* Without scaling, there are no overflow concerns. */
+ if (likely(scale == 0) && can_use_fpu(status)) {
+ union_float32 ur;
+ ur.h = a;
+ return ur.s;
+ }
+
parts_uint_to_float(&p, a, scale, status);
return float32_round_pack_canonical(&p, status);
}
@@ -3759,6 +3780,13 @@ float64 uint64_to_float64_scalbn(uint64_t a, int scale, float_status *status)
{
FloatParts64 p;
+ /* Without scaling, there are no overflow concerns. */
+ if (likely(scale == 0) && can_use_fpu(status)) {
+ union_float64 ur;
+ ur.h = a;
+ return ur.s;
+ }
+
parts_uint_to_float(&p, a, scale, status);
return float64_round_pack_canonical(&p, status);
}
For the normal case of no additional scaling, this reduces the profile contribution of int64_to_float64 to the testcase in the linked issue from 0.81% to 0.04%. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/134 Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- fpu/softfloat.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) -- 2.25.1