RPCSX/llvm
1
0
Fork 0
mirror of https://github.com/RPCSX/llvm.git synced 2024-11-26 21:20:37 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Reprioritize tests for tail duplication to be aggressive about indirect

Browse Source 
branches even when optimizing for code size.  Unless we find evidence to the
contrary in the future, the special treatment for indirect branches does not
have a significant effect on code size, and performance still matters with -Os.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90147 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Bob Wilson 2009-11-30 18:56:45 +00:00
parent 15217e63bc
commit 3858225afc
1 changed files with 3 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
lib/CodeGen/TailDuplication.cpp
View File

@ -116,14 +116,14 @@ bool TailDuplicatePass::TailDuplicate(MachineBasicBlock *TailBB,
// duplicate only one, because one branch instruction can be eliminated to
// compensate for the duplication.
unsigned MaxDuplicateCount;
if (MF.getFunction()->hasFnAttr(Attribute::OptimizeForSize))
MaxDuplicateCount = 1;
else if (!TailBB->empty() && TailBB->back().getDesc().isIndirectBranch())
if (!TailBB->empty() && TailBB->back().getDesc().isIndirectBranch())
// If the target has hardware branch prediction that can handle indirect
// branches, duplicating them can often make them predictable when there
// are common paths through the code. The limit needs to be high enough
// to allow undoing the effects of tail merging.
MaxDuplicateCount = 20;
else if (MF.getFunction()->hasFnAttr(Attribute::OptimizeForSize))
MaxDuplicateCount = 1;
else
MaxDuplicateCount = TailDuplicateSize;