[TCWG CI] 464.h264ref slowed down by 7% after llvm: [JumpThreading] Ignore free instructions

After llvm commit 1e3c6fc7cb9d2ee6a5328881f95d6643afeadbff Author: Nikita Popov [JumpThreading] Ignore free instructions the following benchmarks slowed down by more than 2%: - 464.h264ref slowed down by 7% from 10715 to 11434 perf samples Below reproducer instructions can be used to

[ACTIVITY] report week ending 24 Sep

Progress * UM-2 [QEMU upstream maintainership] + Still looking at the mess that is non-unique bus names. Worked through exactly which devices and machine types are affected for the i2c bus. + Sent a patchset which tries to make the "create a bus" function names a bit more regular

[TCWG CI] 400.perlbench slowed down by 6% after llvm: [SimplifyCFG] Ignore free instructions when computing cost for folding branch to common dest

After llvm commit e7249e4acf3cf9438d6d9e02edecebd5b622a4dc Author: Arthur Eubanks [SimplifyCFG] Ignore free instructions when computing cost for folding branch to common dest the following benchmarks slowed down by more than 2%: - 400.perlbench slowed down by 6% from 9730 to 10312 perf