6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-09-26 09:18:56 +00:00
Code Issues Projects Releases Wiki Activity

This transform only handles two-operand AddRec's. Prevent it from trying to

Browse Source 
handle anything more complex. Fixes PR10383 again!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139186 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nick Lewycky
2011-09-06 21:42:18 +00:00
parent 34c4485b74
commit c103a08a11
2 changed files with 43 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

36
lib/Analysis/ScalarEvolution.cpp
View File

@@ -1974,7 +1974,8 @@ const SCEV *ScalarEvolution::getMulExpr(SmallVectorImpl<const SCEV *> &Ops,
// multiplied together. If so, we can fold them.
for (unsigned OtherIdx = Idx+1;
OtherIdx < Ops.size() && isa<SCEVAddRecExpr>(Ops[OtherIdx]);
++OtherIdx)
++OtherIdx) {
bool Retry = false;
if (AddRecLoop == cast<SCEVAddRecExpr>(Ops[OtherIdx])->getLoop()) {
// {A,+,B}<L> * {C,+,D}<L> --> {A*C,+,A*D + B*C + B*D,+,2*B*D}<L>
//
@@ -1985,7 +1986,7 @@ const SCEV *ScalarEvolution::getMulExpr(SmallVectorImpl<const SCEV *> &Ops,
// Rearranging, X = x, Y = y+z, Z = 2z.
//
// x = A*C, y = (A*D + B*C), z = B*D.
// Therefore X = A*C, Y = (A*D + B*C) + B*D and Z = 2*B*D.
// Therefore X = A*C, Y = A*D + B*C + B*D and Z = 2*B*D.
for (; OtherIdx != Ops.size() && isa<SCEVAddRecExpr>(Ops[OtherIdx]);
++OtherIdx)
if (const SCEVAddRecExpr *OtherAddRec =
@@ -2002,19 +2003,28 @@ const SCEV *ScalarEvolution::getMulExpr(SmallVectorImpl<const SCEV *> &Ops,
const SCEV *NewSecondOrderStep =
getMulExpr(BD, getConstant(BD->getType(), 2));
SmallVector<const SCEV *, 3> AddRecOps;
AddRecOps.push_back(NewStart);
AddRecOps.push_back(NewStep);
AddRecOps.push_back(NewSecondOrderStep);
const SCEV *NewAddRec = getAddRecExpr(AddRecOps,
AddRec->getLoop(),
SCEV::FlagAnyWrap);
if (Ops.size() == 2) return NewAddRec;
Ops[Idx] = AddRec = cast<SCEVAddRecExpr>(NewAddRec);
Ops.erase(Ops.begin() + OtherIdx); --OtherIdx;
// This can happen when AddRec or OtherAddRec have >3 operands.
// TODO: support these add-recs.
if (isLoopInvariant(NewStart, AddRecLoop) &&
isLoopInvariant(NewStep, AddRecLoop) &&
isLoopInvariant(NewSecondOrderStep, AddRecLoop)) {
SmallVector<const SCEV *, 3> AddRecOps;
AddRecOps.push_back(NewStart);
AddRecOps.push_back(NewStep);
AddRecOps.push_back(NewSecondOrderStep);
const SCEV *NewAddRec = getAddRecExpr(AddRecOps,
AddRec->getLoop(),
SCEV::FlagAnyWrap);
if (Ops.size() == 2) return NewAddRec;
Ops[Idx] = AddRec = cast<SCEVAddRecExpr>(NewAddRec);
Ops.erase(Ops.begin() + OtherIdx); --OtherIdx;
Retry = true;
}
}
return getMulExpr(Ops);
if (Retry)
return getMulExpr(Ops);
}
}
// Otherwise couldn't fold anything into this recurrence. Move onto the
// next one.