Commit Graph

2 Commits

Author SHA1 Message Date
Michael Kuperstein d926465342 [X86] Do not generate 64-bit pops of 32-bit GPRs.
When trying emit a stack adjustments using pops, frame lowering selects an
arbitrary free GPR. It should always select one from an appropriate class...
This fixes PR24649.

Patch by: amjad.aboud@intel.com
Differential Revision: http://reviews.llvm.org/D12609

llvm-svn: 247785
2015-09-16 11:27:20 +00:00
Michael Kuperstein 7337ee23d8 [X86] When optimizing for minsize, use POP for small post-call stack clean-up
When optimizing for size, replace "addl $4, %esp" and "addl $8, %esp"
following a call by one or two pops, respectively. We don't try to do it in
general, but only when the stack adjustment immediately follows a call - which
is the most common case.

That allows taking a short-cut when trying to find a free register to pop into,
instead of a full-blown liveness check. If the adjustment immediately follows a
call, then every register the call clobbers but doesn't define should be dead at
that point, and can be used.

Differential Revision: http://reviews.llvm.org/D11749

llvm-svn: 244578
2015-08-11 08:48:48 +00:00