[LLVMdev] [Shrink-Wrapping] Request For Benchmarking: X86 and AArch64

[Quentin Colombet]

Hi,

Shrink-wrapping capabilities, i.e., better placement of prologue and epilogue sequences, landed in r236507 but are not yet enabled by default.

Since r236507 AArch64 is shrink-wrapping ready, meaning we can turn the pass on for this target.
I’ve done the same for X86 in r 238293.

Now, I need your help to test and benchmark how shrink-wrapping perform on those targets.

The goal is to decide whether or not the support is good enough to be enabled by default.


** How Can I Test/Benchmark It? **

Add (-mllvm) -enable-shrink-wrap on your command line or patch the XXXConfigPass to set EnableShrinkWrap to true.
Note the -enable-shrink-wrap=<bool> takes precedence over whatever is set for EnableShrinkWrap.

Please report any problem specific to this optimization turned on. A PR with a small IR to reproduce are appreciated.

Note: I’ve seem up to 4% runtime improvements on the LLVM test-suite + specs for Os and O3.


Thanks in advance for your help,
-Quentin