Confirmed, although "65% decrease" is on 0.44% of the total execution for this test case, so the decrease isn't actually noticeable.
Nevertheless, it's a simple enough change. ** Changed in: qemu Status: New => In Progress ** Changed in: qemu Assignee: (unassigned) => Richard Henderson (rth) -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1892081 Title: Performance improvement when using "QEMU_FLATTEN" with softfloat type conversions Status in QEMU: In Progress Bug description: Attached below is a matrix multiplication program for double data types. The program performs the casting operation "(double)rand()" when generating random numbers. This operation calls the integer to float softfloat conversion function "int32_to_float_64". Adding the "QEMU_FLATTEN" attribute to the function definition decreases the instructions per call of the function by about 63%. Attached are before and after performance screenshots from KCachegrind. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1892081/+subscriptions