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Diffstat (limited to 'mailinglist/output_launchpad/1892081')
| -rw-r--r-- | mailinglist/output_launchpad/1892081 | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/mailinglist/output_launchpad/1892081 b/mailinglist/output_launchpad/1892081 new file mode 100644 index 00000000..a05b89e6 --- /dev/null +++ b/mailinglist/output_launchpad/1892081 @@ -0,0 +1,35 @@ +Performance improvement when using "QEMU_FLATTEN" with softfloat type conversions + +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. + + + + + + + +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. + + +This is an automated cleanup. This bug report has been moved to QEMU's +new bug tracker on gitlab.com and thus gets marked as 'expired' now. +Please continue with the discussion here: + + https://gitlab.com/qemu-project/qemu/-/issues/134 + + |