[llvm-commits] [llvm] r169288 - in /llvm/trunk: lib/Transforms/Vectorize/LoopVectorize.cpp test/Transforms/LoopVectorize/if-conversion.ll
Nadav Rotem
nrotem at apple.com
Tue Dec 4 10:17:34 PST 2012
Author: nadav
Date: Tue Dec 4 12:17:33 2012
New Revision: 169288
URL: http://llvm.org/viewvc/llvm-project?rev=169288&view=rev
Log:
Add support for reduction variables when IF-conversion is enabled.
Modified:
llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp
llvm/trunk/test/Transforms/LoopVectorize/if-conversion.ll
Modified: llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp?rev=169288&r1=169287&r2=169288&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp Tue Dec 4 12:17:33 2012
@@ -1133,8 +1133,8 @@
// Reductions do not have to start at zero. They can start with
// any loop invariant values.
VecRdxPhi->addIncoming(VectorStart, VecPreheader);
- unsigned SelfEdgeIdx = (RdxPhi)->getBasicBlockIndex(LoopScalarBody);
- Value *Val = getVectorValue(RdxPhi->getIncomingValue(SelfEdgeIdx));
+ Value *Val =
+ getVectorValue(RdxPhi->getIncomingValueForBlock(OrigLoop->getLoopLatch()));
VecRdxPhi->addIncoming(Val, LoopVectorBody);
// Before each round, move the insertion point right between
@@ -1201,8 +1201,11 @@
// Fix the scalar loop reduction variable with the incoming reduction sum
// from the vector body and from the backedge value.
- int IncomingEdgeBlockIdx = (RdxPhi)->getBasicBlockIndex(LoopScalarBody);
- int SelfEdgeBlockIdx = (IncomingEdgeBlockIdx ? 0 : 1); // The other block.
+ int IncomingEdgeBlockIdx =
+ (RdxPhi)->getBasicBlockIndex(OrigLoop->getLoopLatch());
+ assert(IncomingEdgeBlockIdx >= 0 && "Invalid block index");
+ // Pick the other block.
+ int SelfEdgeBlockIdx = (IncomingEdgeBlockIdx ? 0 : 1);
(RdxPhi)->setIncomingValue(SelfEdgeBlockIdx, Scalar0);
(RdxPhi)->setIncomingValue(IncomingEdgeBlockIdx, RdxDesc.LoopExitInstr);
}// end of for each redux variable.
@@ -1961,11 +1964,13 @@
if (Phi->getNumIncomingValues() != 2)
return false;
- // Find the possible incoming reduction variable.
- BasicBlock *BB = Phi->getParent();
- int SelfEdgeIdx = Phi->getBasicBlockIndex(BB);
- int InEdgeBlockIdx = (SelfEdgeIdx ? 0 : 1); // The other entry.
- Value *RdxStart = Phi->getIncomingValue(InEdgeBlockIdx);
+ // Reduction variables are only found in the loop header block.
+ if (Phi->getParent() != TheLoop->getHeader())
+ return false;
+
+ // Obtain the reduction start value from the value that comes from the loop
+ // preheader.
+ Value *RdxStart = Phi->getIncomingValueForBlock(TheLoop->getLoopPreheader());
// ExitInstruction is the single value which is used outside the loop.
// We only allow for a single reduction value to be used outside the loop.
@@ -2003,9 +2008,17 @@
FoundStartPHI = true;
continue;
}
+
+ // We allow in-loop PHINodes which are not the original reduction PHI
+ // node. If this PHI is the only user of Iter (happens in IF w/ no ELSE
+ // structure) then don't skip this PHI.
+ if (isa<PHINode>(U) && U->getParent() != TheLoop->getHeader() &&
+ TheLoop->contains(U->getParent()) && Iter->getNumUses() > 1)
+ continue;
+
// Check if we found the exit user.
BasicBlock *Parent = U->getParent();
- if (Parent != BB) {
+ if (!TheLoop->contains(Parent)) {
// We must have a single exit instruction.
if (ExitInstruction != 0)
return false;
Modified: llvm/trunk/test/Transforms/LoopVectorize/if-conversion.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopVectorize/if-conversion.ll?rev=169288&r1=169287&r2=169288&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LoopVectorize/if-conversion.ll (original)
+++ llvm/trunk/test/Transforms/LoopVectorize/if-conversion.ll Tue Dec 4 12:17:33 2012
@@ -58,3 +58,51 @@
for.end:
ret i32 undef
}
+
+
+
+; int func(int *A, int n) {
+; unsigned sum = 0;
+; for (int i = 0; i < n; ++i)
+; if (A[i] > 30)
+; sum += A[i] + 2;
+;
+; return sum;
+; }
+
+;CHECK: @reduction_func
+;CHECK: load <4 x i32>
+;CHECK: icmp sgt <4 x i32>
+;CHECK: add <4 x i32>
+;CHECK: select <4 x i1>
+;CHECK: ret i32
+define i32 @reduction_func(i32* nocapture %A, i32 %n) nounwind uwtable readonly ssp {
+entry:
+ %cmp10 = icmp sgt i32 %n, 0
+ br i1 %cmp10, label %for.body, label %for.end
+
+for.body: ; preds = %entry, %for.inc
+ %indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ]
+ %sum.011 = phi i32 [ %sum.1, %for.inc ], [ 0, %entry ]
+ %arrayidx = getelementptr inbounds i32* %A, i64 %indvars.iv
+ %0 = load i32* %arrayidx, align 4
+ %cmp1 = icmp sgt i32 %0, 30
+ br i1 %cmp1, label %if.then, label %for.inc
+
+if.then: ; preds = %for.body
+ %add = add i32 %sum.011, 2
+ %add4 = add i32 %add, %0
+ br label %for.inc
+
+for.inc: ; preds = %for.body, %if.then
+ %sum.1 = phi i32 [ %add4, %if.then ], [ %sum.011, %for.body ]
+ %indvars.iv.next = add i64 %indvars.iv, 1
+ %lftr.wideiv = trunc i64 %indvars.iv.next to i32
+ %exitcond = icmp eq i32 %lftr.wideiv, %n
+ br i1 %exitcond, label %for.end, label %for.body
+
+for.end: ; preds = %for.inc, %entry
+ %sum.0.lcssa = phi i32 [ 0, %entry ], [ %sum.1, %for.inc ]
+ ret i32 %sum.0.lcssa
+}
+
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