[llvm] r187265 - SLP Vectorizer: Disable the vectorization of non power of two chains, such as <3 x float>, because we dont have a good cost model for these types.

Nadav Rotem nrotem at apple.com
Fri Jul 26 15:53:12 PDT 2013


Author: nadav
Date: Fri Jul 26 17:53:11 2013
New Revision: 187265

URL: http://llvm.org/viewvc/llvm-project?rev=187265&view=rev
Log:
SLP Vectorizer: Disable the vectorization of non power of two chains, such as <3 x float>, because we dont have a good cost model for these types.

Modified:
    llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp
    llvm/trunk/test/Transforms/SLPVectorizer/X86/cycle_dup.ll
    llvm/trunk/test/Transforms/SLPVectorizer/X86/odd_store.ll

Modified: llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp?rev=187265&r1=187264&r2=187265&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp Fri Jul 26 17:53:11 2013
@@ -1664,23 +1664,7 @@ bool SLPVectorizer::vectorizeStoreChain(
     }
   }
 
-  if (Changed || ChainLen > VF)
     return Changed;
-
-  // Handle short chains. This helps us catch types such as <3 x float> that
-  // are smaller than vector size.
-  R.buildTree(Chain);
-
-  int Cost = R.getTreeCost();
-
-  if (Cost < CostThreshold) {
-    DEBUG(dbgs() << "SLP: Found store chain cost = " << Cost
-          << " for size = " << ChainLen << "\n");
-    R.vectorizeTree();
-    return true;
-  }
-
-  return false;
 }
 
 bool SLPVectorizer::vectorizeStores(ArrayRef<StoreInst *> Stores,

Modified: llvm/trunk/test/Transforms/SLPVectorizer/X86/cycle_dup.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SLPVectorizer/X86/cycle_dup.ll?rev=187265&r1=187264&r2=187265&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SLPVectorizer/X86/cycle_dup.ll (original)
+++ llvm/trunk/test/Transforms/SLPVectorizer/X86/cycle_dup.ll Fri Jul 26 17:53:11 2013
@@ -3,55 +3,61 @@
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
 target triple = "x86_64-apple-macosx10.9.0"
 
-
 ; int foo(int *A) {
-;   int r = A[0], g = A[1], b = A[2];
-;   for (int i=0; i < A[13]; i++)
-;     r*=18; g*=19; b*=12;
-;   A[0] = r; A[1] = g; A[2] = b;
+;   int r = A[0], g = A[1], b = A[2], a = A[3];
+;   for (int i=0; i < A[13]; i++) {
+;     r*=18; g*=19; b*=12; a *=9;
+;   }
+;   A[0] = r; A[1] = g; A[2] = b; A[3] = a;
 ; }
 
 ;CHECK-LABEL: @foo
-;CHECK: bitcast i32* %A to <3 x i32>*
-;CHECK-NEXT: load <3 x i32>
-;CHECK: phi <3 x i32>
-;CHECK-NEXT: mul <3 x i32>
+;CHECK: bitcast i32* %A to <4 x i32>*
+;CHECK-NEXT: load <4 x i32>
+;CHECK: phi <4 x i32>
+;CHECK-NEXT: mul <4 x i32>
 ;CHECK-NOT: mul
-;CHECK: phi <3 x i32>
-;CHECK: bitcast i32* %A to <3 x i32>*
-;CHECK-NEXT: store <3 x i32>
+;CHECK: phi <4 x i32>
+;CHECK: bitcast i32* %A to <4 x i32>*
+;CHECK-NEXT: store <4 x i32>
 ;CHECK-NEXT:ret i32 undef
-define i32 @foo(i32* nocapture %A) {
+define i32 @foo(i32* nocapture %A) #0 {
 entry:
   %0 = load i32* %A, align 4
   %arrayidx1 = getelementptr inbounds i32* %A, i64 1
   %1 = load i32* %arrayidx1, align 4
   %arrayidx2 = getelementptr inbounds i32* %A, i64 2
   %2 = load i32* %arrayidx2, align 4
-  %arrayidx3 = getelementptr inbounds i32* %A, i64 13
+  %arrayidx3 = getelementptr inbounds i32* %A, i64 3
   %3 = load i32* %arrayidx3, align 4
-  %cmp18 = icmp sgt i32 %3, 0
-  br i1 %cmp18, label %for.body, label %for.end
+  %arrayidx4 = getelementptr inbounds i32* %A, i64 13
+  %4 = load i32* %arrayidx4, align 4
+  %cmp24 = icmp sgt i32 %4, 0
+  br i1 %cmp24, label %for.body, label %for.end
 
 for.body:                                         ; preds = %entry, %for.body
-  %i.022 = phi i32 [ %inc, %for.body ], [ 0, %entry ]
-  %b.021 = phi i32 [ %mul5, %for.body ], [ %2, %entry ]
-  %g.020 = phi i32 [ %mul4, %for.body ], [ %1, %entry ]
-  %r.019 = phi i32 [ %mul, %for.body ], [ %0, %entry ]
-  %mul = mul nsw i32 %r.019, 18
-  %mul4 = mul nsw i32 %g.020, 19
-  %mul5 = mul nsw i32 %b.021, 12
-  %inc = add nsw i32 %i.022, 1
-  %cmp = icmp slt i32 %inc, %3
+  %i.029 = phi i32 [ %inc, %for.body ], [ 0, %entry ]
+  %a.028 = phi i32 [ %mul7, %for.body ], [ %3, %entry ]
+  %b.027 = phi i32 [ %mul6, %for.body ], [ %2, %entry ]
+  %g.026 = phi i32 [ %mul5, %for.body ], [ %1, %entry ]
+  %r.025 = phi i32 [ %mul, %for.body ], [ %0, %entry ]
+  %mul = mul nsw i32 %r.025, 18
+  %mul5 = mul nsw i32 %g.026, 19
+  %mul6 = mul nsw i32 %b.027, 12
+  %mul7 = mul nsw i32 %a.028, 9
+  %inc = add nsw i32 %i.029, 1
+  %cmp = icmp slt i32 %inc, %4
   br i1 %cmp, label %for.body, label %for.end
 
 for.end:                                          ; preds = %for.body, %entry
-  %b.0.lcssa = phi i32 [ %2, %entry ], [ %mul5, %for.body ]
-  %g.0.lcssa = phi i32 [ %1, %entry ], [ %mul4, %for.body ]
+  %a.0.lcssa = phi i32 [ %3, %entry ], [ %mul7, %for.body ]
+  %b.0.lcssa = phi i32 [ %2, %entry ], [ %mul6, %for.body ]
+  %g.0.lcssa = phi i32 [ %1, %entry ], [ %mul5, %for.body ]
   %r.0.lcssa = phi i32 [ %0, %entry ], [ %mul, %for.body ]
   store i32 %r.0.lcssa, i32* %A, align 4
   store i32 %g.0.lcssa, i32* %arrayidx1, align 4
   store i32 %b.0.lcssa, i32* %arrayidx2, align 4
+  store i32 %a.0.lcssa, i32* %arrayidx3, align 4
   ret i32 undef
 }
 

Modified: llvm/trunk/test/Transforms/SLPVectorizer/X86/odd_store.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SLPVectorizer/X86/odd_store.ll?rev=187265&r1=187264&r2=187265&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SLPVectorizer/X86/odd_store.ll (original)
+++ llvm/trunk/test/Transforms/SLPVectorizer/X86/odd_store.ll Fri Jul 26 17:53:11 2013
@@ -10,12 +10,12 @@ target triple = "x86_64-apple-macosx10.8
 ;}
 
 ;CHECK-LABEL: @foo(
-;CHECK: load <3 x float>
-;CHECK: fmul <3 x float>
-;CHECK: fpext <3 x float>
-;CHECK: fadd <3 x double>
-;CHECK: fptosi <3 x double>
-;CHECK: store <3 x i8>
+;CHECK-NOT: load <3 x float>
+;CHECK-NOT: fmul <3 x float>
+;CHECK-NOT: fpext <3 x float>
+;CHECK-NOT: fadd <3 x double>
+;CHECK-NOT: fptosi <3 x double>
+;CHECK-NOT: store <3 x i8>
 ;CHECK: ret
 define i32 @foo(i8* noalias nocapture %A, float* noalias nocapture %B, float %T) {
   %1 = getelementptr inbounds float* %B, i64 10





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