The cost of splitting a large vector instruction is not being taken i…

…nto account by the getUserCost function. This was leading to some loops being over unrolled. The cost of a vector instruction is now being multiplied by the cost of the type legalization. This will return a more accurate cost. Committing on behalf on Brad Nemanich ([email protected]) Differential Revision: https://reviews.llvm.org/D38961 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316174 91177308-0d34-0410-b5e6-96231b3b80d8
hacxman · Oct 19, 2017 · 1f93c85 · 1f93c85
1 parent cb5868c
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diff --git a/lib/Target/PowerPC/PPCTargetTransformInfo.cpp b/lib/Target/PowerPC/PPCTargetTransformInfo.cpp
@@ -189,6 +189,17 @@ int PPCTTIImpl::getIntImmCost(unsigned Opcode, unsigned Idx, const APInt &Imm,
   return PPCTTIImpl::getIntImmCost(Imm, Ty);
 }
 
+unsigned PPCTTIImpl::getUserCost(const User *U,
+                                 ArrayRef<const Value *> Operands) {
+  if (U->getType()->isVectorTy()) {
+    // Instructions that need to be split should cost more.
+    std::pair<int, MVT> LT = TLI->getTypeLegalizationCost(DL, U->getType());
+    return LT.first * BaseT::getUserCost(U, Operands);
+  }
+
+  return BaseT::getUserCost(U, Operands);
+}
+
 void PPCTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
                                          TTI::UnrollingPreferences &UP) {
   if (ST->getDarwinDirective() == PPC::DIR_A2) {

diff --git a/lib/Target/PowerPC/PPCTargetTransformInfo.h b/lib/Target/PowerPC/PPCTargetTransformInfo.h
@@ -51,6 +51,8 @@ class PPCTTIImpl : public BasicTTIImplBase<PPCTTIImpl> {
   int getIntImmCost(Intrinsic::ID IID, unsigned Idx, const APInt &Imm,
                     Type *Ty);
 
+  unsigned getUserCost(const User *U, ArrayRef<const Value *> Operands);
+
   TTI::PopcntSupportKind getPopcntSupport(unsigned TyWidth);
   void getUnrollingPreferences(Loop *L, ScalarEvolution &SE,
                                TTI::UnrollingPreferences &UP);

diff --git a/test/Transforms/LoopUnroll/PowerPC/p8-unrolling-legalize-vectors.ll b/test/Transforms/LoopUnroll/PowerPC/p8-unrolling-legalize-vectors.ll
@@ -0,0 +1,74 @@
+; RUN: opt < %s -S -mtriple=powerpc64le-unknown-linux-gnu -mcpu=pwr8 -loop-unroll | FileCheck %s
+; RUN: opt < %s -S -mtriple=powerpc64le-unknown-linux-gnu -mcpu=pwr9 -loop-unroll | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-n32:64"
+target triple = "powerpc64le-unknown-linux-gnu"
+
+; Function Attrs: norecurse nounwind
+define i8* @f(i8* returned %s, i32 zeroext %x, i32 signext %k) local_unnamed_addr #0 {
+entry:
+  %cmp10 = icmp sgt i32 %k, 0
+  br i1 %cmp10, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  %wide.trip.count = zext i32 %k to i64
+  %min.iters.check = icmp ult i32 %k, 16
+  br i1 %min.iters.check, label %for.body.preheader, label %vector.ph
+
+vector.ph:                                        ; preds = %for.body.lr.ph
+  %n.vec = and i64 %wide.trip.count, 4294967280
+  %broadcast.splatinsert = insertelement <16 x i32> undef, i32 %x, i32 0
+  %broadcast.splat = shufflevector <16 x i32> %broadcast.splatinsert, <16 x i32> undef, <16 x i32> zeroinitializer
+  br label %vector.body
+
+vector.body:                                      ; preds = %vector.body, %vector.ph
+  %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
+  %vec.ind12 = phi <16 x i32> [ <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7, i32 8, i32 9, i32 10, i32 11, i32 12, i32 13, i32 14, i32 15>, %vector.ph ], [ %vec.ind.next13, %vector.body ]
+  %0 = shl <16 x i32> <i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1>, %vec.ind12
+  %1 = and <16 x i32> %0, %broadcast.splat
+  %2 = icmp eq <16 x i32> %1, zeroinitializer
+  %3 = select <16 x i1> %2, <16 x i8> <i8 48, i8 48, i8 48, i8 48, i8 48, i8 48, i8 48, i8 48, i8 48, i8 48, i8 48, i8 48, i8 48, i8 48, i8 48, i8 48>, <16 x i8> <i8 49, i8 49, i8 49, i8 49, i8 49, i8 49, i8 49, i8 49, i8 49, i8 49, i8 49, i8 49, i8 49, i8 49, i8 49, i8 49>
+  %4 = getelementptr inbounds i8, i8* %s, i64 %index
+  %5 = bitcast i8* %4 to <16 x i8>*
+  store <16 x i8> %3, <16 x i8>* %5, align 1
+  %index.next = add i64 %index, 16
+  %vec.ind.next13 = add <16 x i32> %vec.ind12, <i32 16, i32 16, i32 16, i32 16, i32 16, i32 16, i32 16, i32 16, i32 16, i32 16, i32 16, i32 16, i32 16, i32 16, i32 16, i32 16>
+  %6 = icmp eq i64 %index.next, %n.vec
+  br i1 %6, label %middle.block, label %vector.body
+
+middle.block:                                     ; preds = %vector.body
+  %cmp.n = icmp eq i64 %n.vec, %wide.trip.count
+  br i1 %cmp.n, label %for.end, label %for.body.preheader
+
+for.body.preheader:                               ; preds = %middle.block, %for.body.lr.ph
+  %indvars.iv.ph = phi i64 [ 0, %for.body.lr.ph ], [ %n.vec, %middle.block ]
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.preheader, %for.body
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ %indvars.iv.ph, %for.body.preheader ]
+  %7 = trunc i64 %indvars.iv to i32
+  %shl = shl i32 1, %7
+  %and = and i32 %shl, %x
+  %tobool = icmp eq i32 %and, 0
+  %conv = select i1 %tobool, i8 48, i8 49
+  %arrayidx = getelementptr inbounds i8, i8* %s, i64 %indvars.iv
+  store i8 %conv, i8* %arrayidx, align 1
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond = icmp eq i64 %indvars.iv.next, %wide.trip.count
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:                                          ; preds = %for.body, %middle.block, %entry
+  %idxprom1 = sext i32 %k to i64
+  %arrayidx2 = getelementptr inbounds i8, i8* %s, i64 %idxprom1
+  store i8 0, i8* %arrayidx2, align 1
+  ret i8* %s
+}
+
+
+; CHECK-LABEL: vector.body
+; CHECK:      shl
+; CHECK-NEXT: and
+; CHECK: shl
+; CHECK-NEXT: and
+; CHECK: label %vector.body
+