[llvm] r234670 - [PowerPC] Fix PPCLoopPreIncPrep for depth > 1 loops
Hal Finkel
hfinkel at anl.gov
Fri Apr 10 17:33:08 PDT 2015
Author: hfinkel
Date: Fri Apr 10 19:33:08 2015
New Revision: 234670
URL: http://llvm.org/viewvc/llvm-project?rev=234670&view=rev
Log:
[PowerPC] Fix PPCLoopPreIncPrep for depth > 1 loops
This pass had the same problem as the data-prefetching pass: it was only
checking for depth == 1 loops in practice. Fix that, add some debugging
statements, and make sure that, when we grab an AddRec, it is for the loop we
expect.
Added:
llvm/trunk/test/CodeGen/PowerPC/pip-inner.ll
Modified:
llvm/trunk/lib/Target/PowerPC/PPCLoopPreIncPrep.cpp
Modified: llvm/trunk/lib/Target/PowerPC/PPCLoopPreIncPrep.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCLoopPreIncPrep.cpp?rev=234670&r1=234669&r2=234670&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCLoopPreIncPrep.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCLoopPreIncPrep.cpp Fri Apr 10 19:33:08 2015
@@ -22,6 +22,7 @@
#define DEBUG_TYPE "ppc-loop-preinc-prep"
#include "PPC.h"
#include "PPCTargetMachine.h"
+#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/Statistic.h"
@@ -143,8 +144,10 @@ bool PPCLoopPreIncPrep::runOnFunction(Fu
bool MadeChange = false;
- for (LoopInfo::iterator I = LI->begin(), E = LI->end();
- I != E; ++I) {
+ if (LI->empty())
+ return MadeChange;
+
+ for (auto I = df_begin(*LI->begin()), E = df_end(*LI->begin()); I != E; ++I) {
Loop *L = *I;
MadeChange |= runOnLoop(L);
}
@@ -159,16 +162,15 @@ bool PPCLoopPreIncPrep::runOnLoop(Loop *
if (!L->empty())
return MadeChange;
+ DEBUG(dbgs() << "PIP: Examining: " << *L << "\n");
+
BasicBlock *Header = L->getHeader();
const PPCSubtarget *ST =
TM ? TM->getSubtargetImpl(*Header->getParent()) : nullptr;
- unsigned HeaderLoopPredCount = 0;
- for (pred_iterator PI = pred_begin(Header), PE = pred_end(Header);
- PI != PE; ++PI) {
- ++HeaderLoopPredCount;
- }
+ unsigned HeaderLoopPredCount =
+ std::distance(pred_begin(Header), pred_end(Header));
// Collect buckets of comparable addresses used by loads and stores.
typedef std::multimap<const SCEV *, Instruction *, SCEVLess> Bucket;
@@ -205,9 +207,13 @@ bool PPCLoopPreIncPrep::runOnLoop(Loop *
if (L->isLoopInvariant(PtrValue))
continue;
- const SCEV *LSCEV = SE->getSCEV(PtrValue);
- if (!isa<SCEVAddRecExpr>(LSCEV))
+ const SCEV *LSCEV = SE->getSCEVAtScope(PtrValue, L);
+ if (const SCEVAddRecExpr *LARSCEV = dyn_cast<SCEVAddRecExpr>(LSCEV)) {
+ if (LARSCEV->getLoop() != L)
+ continue;
+ } else {
continue;
+ }
bool FoundBucket = false;
for (unsigned i = 0, e = Buckets.size(); i != e; ++i)
@@ -236,11 +242,16 @@ bool PPCLoopPreIncPrep::runOnLoop(Loop *
// returns a value (which might contribute to determining the loop's
// iteration space), insert a new preheader for the loop.
if (!LoopPredecessor ||
- !LoopPredecessor->getTerminator()->getType()->isVoidTy())
+ !LoopPredecessor->getTerminator()->getType()->isVoidTy()) {
LoopPredecessor = InsertPreheaderForLoop(L, this);
+ if (LoopPredecessor)
+ MadeChange = true;
+ }
if (!LoopPredecessor)
return MadeChange;
+ DEBUG(dbgs() << "PIP: Found " << Buckets.size() << " buckets\n");
+
SmallSet<BasicBlock *, 16> BBChanged;
for (unsigned i = 0, e = Buckets.size(); i != e; ++i) {
// The base address of each bucket is transformed into a phi and the others
@@ -251,6 +262,10 @@ bool PPCLoopPreIncPrep::runOnLoop(Loop *
if (!BasePtrSCEV->isAffine())
continue;
+ DEBUG(dbgs() << "PIP: Transforming: " << *BasePtrSCEV << "\n");
+ assert(BasePtrSCEV->getLoop() == L &&
+ "AddRec for the wrong loop?");
+
Instruction *MemI = Buckets[i].begin()->second;
Value *BasePtr = GetPointerOperand(MemI);
assert(BasePtr && "No pointer operand");
@@ -271,6 +286,8 @@ bool PPCLoopPreIncPrep::runOnLoop(Loop *
if (!isSafeToExpand(BasePtrStartSCEV, *SE))
continue;
+ DEBUG(dbgs() << "PIP: New start is: " << *BasePtrStartSCEV << "\n");
+
PHINode *NewPHI = PHINode::Create(I8PtrTy, HeaderLoopPredCount,
MemI->hasName() ? MemI->getName() + ".phi" : "",
Header->getFirstNonPHI());
Added: llvm/trunk/test/CodeGen/PowerPC/pip-inner.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/pip-inner.ll?rev=234670&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/pip-inner.ll (added)
+++ llvm/trunk/test/CodeGen/PowerPC/pip-inner.ll Fri Apr 10 19:33:08 2015
@@ -0,0 +1,52 @@
+; RUN: llc < %s | FileCheck %s
+target datalayout = "E-m:e-i64:64-n32:64"
+target triple = "powerpc64-unknown-linux-gnu"
+
+; Function Attrs: nounwind
+define void @foo(double* %x, double* nocapture readonly %y) #0 {
+entry:
+ br label %for.cond1.preheader
+
+for.cond1.preheader: ; preds = %for.end, %entry
+ %i.015 = phi i32 [ 0, %entry ], [ %inc7, %for.end ]
+ br label %for.body3
+
+for.body3: ; preds = %for.body3, %for.cond1.preheader
+ %indvars.iv = phi i64 [ 0, %for.cond1.preheader ], [ %indvars.iv.next, %for.body3 ]
+ %arrayidx = getelementptr inbounds double, double* %y, i64 %indvars.iv
+ %0 = load double, double* %arrayidx, align 8
+ %add = fadd double %0, 1.000000e+00
+ %arrayidx5 = getelementptr inbounds double, double* %x, i64 %indvars.iv
+ store double %add, double* %arrayidx5, align 8
+ %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+ %exitcond = icmp eq i64 %indvars.iv.next, 16000
+ br i1 %exitcond, label %for.end, label %for.body3
+
+for.end: ; preds = %for.body3
+ tail call void @bar(double* %x) #2
+ %inc7 = add nuw nsw i32 %i.015, 1
+ %exitcond16 = icmp eq i32 %inc7, 1000
+ br i1 %exitcond16, label %for.end8, label %for.cond1.preheader
+
+for.end8: ; preds = %for.end
+ ret void
+
+; CHECK-LABEL: @foo
+
+; CHECK: lfdu [[REG1:[0-9]+]], 8({{[0-9]+}})
+; CHECK: fadd [[REG2:[0-9]+]], [[REG1]], {{[0-9]+}}
+; CHECK: stfdu [[REG2]], 8({{[0-9]+}})
+; CHECK: bdnz
+
+; CHECK: bl bar
+; CHECK-NEXT: nop
+
+; CHECK: blr
+}
+
+declare void @bar(double*) #1
+
+attributes #0 = { nounwind "target-cpu"="a2" }
+attributes #1 = { "target-cpu"="a2" }
+attributes #2 = { nounwind }
+
More information about the llvm-commits
mailing list