nicolas/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

[StackColoring] Update AliasAnalysis information in stack coloring pass (part 2)

Browse Source 
This patch is update after the first patch (https://reviews.llvm.org/rL309651) based on the post-commit comments.

Stack coloring pass need to maintain AliasAnalysis information when merging stack slots of different types.
Actually, there is a FIXME comment in StackColoring.cpp

// FIXME: In order to enable the use of TBAA when using AA in CodeGen,
// we'll also need to update the TBAA nodes in MMOs with values
// derived from the merged allocas.

But, TBAA has been already enabled in CodeGen without fixing this pass.
The incorrect TBAA metadata results in recent failures in bootstrap test on ppc64le (PR33928) by allowing unsafe instruction scheduling.
Although we observed the problem on ppc64le, this is a platform neutral issue.

This patch makes the stack coloring pass maintains AliasAnalysis information when merging multiple stack slots.

This patch fixes PR33928.

llvm-svn: 309849
This commit is contained in:
Hiroshi Inoue
2017-08-02 18:16:32 +00:00
parent f67036b62c
commit 0bd906ec8f
2 changed files with 10 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
llvm/lib/CodeGen/StackColoring.cpp
View File

@@ -1001,7 +1001,7 @@ void StackColoring::remapInstructions(DenseMap<int, int> &SlotRemap) {
}
// We adjust AliasAnalysis information for merged stack slots.
MachineSDNode::mmo_iterator MemOps =
MachineSDNode::mmo_iterator NewMemOps =
MF->allocateMemRefsArray(I.getNumMemOperands());
unsigned MemOpIdx = 0;
bool ReplaceMemOps = false;
@@ -1030,17 +1030,17 @@ void StackColoring::remapInstructions(DenseMap<int, int> &SlotRemap) {
}
}
if (MayHaveConflictingAAMD) {
MemOps[MemOpIdx++] = MF->getMachineMemOperand(MMO, AAMDNodes());
NewMemOps[MemOpIdx++] = MF->getMachineMemOperand(MMO, AAMDNodes());
ReplaceMemOps = true;
}
else
MemOps[MemOpIdx++] = MMO;
NewMemOps[MemOpIdx++] = MMO;
}
// If any memory operand is updated, set memory references of
// this instruction.
if (ReplaceMemOps)
I.setMemRefs(std::make_pair(MemOps, I.getNumMemOperands()));
I.setMemRefs(std::make_pair(NewMemOps, I.getNumMemOperands()));
}
// Update the location of C++ catch objects for the MSVC personality routine.