RPCSX/llvm
1
0
Fork 0
mirror of https://github.com/RPCSX/llvm.git synced 2024-12-14 23:48:49 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Remove the user-count threshold when analyzing read attributes

Browse Source 
Summary:
This threshold limited FunctionAttrs ability to prove arguments to be read-only. 
In NVPTX, a specialized instruction ld.global.nc can be used to load memory
with non-coherent texture cache. We notice that in SHOC [1] benchmark, some
function arguments are not marked with readonly because FunctionAttrs reaches
a hardcoded threshold when analysis uses.

Removing this threshold won't cause significant regression in compilation time, because the worst-case time complexity of the algorithm is still O(# of instructions) for each parameter.

Patched by Xuetian Weng.  

[1] https://github.com/vetter/shoc

Reviewers: nlewycky, jingyue, nicholas

Subscribers: nicholas, test, llvm-commits

Differential Revision: http://reviews.llvm.org/D11311

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243141 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jingyue Wu 2015-07-24 19:05:53 +00:00
parent ec2871f730
commit ab0a70d3a3
1 changed files with 0 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
lib/Transforms/IPO/FunctionAttrs.cpp
View File

@ -425,9 +425,6 @@ determinePointerReadAttrs(Argument *A,
// We don't need to track IsWritten. If A is written to, return immediately. // We don't need to track IsWritten. If A is written to, return immediately.
for (Use &U : A->uses()) { for (Use &U : A->uses()) {
if (Count++ >= 20)
return Attribute::None;
Visited.insert(&U); Visited.insert(&U);
Worklist.push_back(&U); Worklist.push_back(&U);
} }