[PATCH] D13254: [LAA] LLE 1/6: Expose Forward dependences

[Adam Nemet via llvm-commits]

This revision was automatically updated to reflect the committed changes.
Closed by commit rL251972: [LAA] LLE 1/6: Expose Forward dependences (authored by anemet).

Changed prior to commit:
  http://reviews.llvm.org/D13254?vs=35998&id=39099#toc

Repository:
  rL LLVM

http://reviews.llvm.org/D13254

Files:
  llvm/trunk/lib/Analysis/LoopAccessAnalysis.cpp
  llvm/trunk/test/Analysis/LoopAccessAnalysis/forward-loop-carried.ll
  llvm/trunk/test/Analysis/LoopAccessAnalysis/safe-no-checks.ll

Index: llvm/trunk/lib/Analysis/LoopAccessAnalysis.cpp
===================================================================
--- llvm/trunk/lib/Analysis/LoopAccessAnalysis.cpp
+++ llvm/trunk/lib/Analysis/LoopAccessAnalysis.cpp
@@ -911,19 +911,7 @@
 }
 
 bool MemoryDepChecker::Dependence::isInterestingDependence(DepType Type) {
-  switch (Type) {
-  case NoDep:
-  case Forward:
-    return false;
-
-  case BackwardVectorizable:
-  case Unknown:
-  case ForwardButPreventsForwarding:
-  case Backward:
-  case BackwardVectorizableButPreventsForwarding:
-    return true;
-  }
-  llvm_unreachable("unexpected DepType!");
+  return Type != NoDep;
 }
 
 bool MemoryDepChecker::Dependence::isPossiblyBackward() const {
Index: llvm/trunk/test/Analysis/LoopAccessAnalysis/safe-no-checks.ll
===================================================================
--- llvm/trunk/test/Analysis/LoopAccessAnalysis/safe-no-checks.ll
+++ llvm/trunk/test/Analysis/LoopAccessAnalysis/safe-no-checks.ll
@@ -7,7 +7,15 @@
 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-apple-macosx10.10.0"
 
+; Check the loop-carried forward anti-dep between the load of A[i+1] and the
+; store of A[i];
+
 ; CHECK: Memory dependences are safe{{$}}
+; CHECK-NEXT: Interesting Dependences:
+; CHECK-NEXT:   Forward:
+; CHECK-NEXT:     %loadA_plus_2 = load i16, i16* %arrayidxA_plus_2, align 2 ->
+; CHECK-NEXT:     store i16 %mul1, i16* %arrayidxA, align 2
+
 
 define void @f(i16* noalias %a,
                i16* noalias %b,
Index: llvm/trunk/test/Analysis/LoopAccessAnalysis/forward-loop-carried.ll
===================================================================
--- llvm/trunk/test/Analysis/LoopAccessAnalysis/forward-loop-carried.ll
+++ llvm/trunk/test/Analysis/LoopAccessAnalysis/forward-loop-carried.ll
@@ -0,0 +1,44 @@
+; RUN: opt -loop-accesses -analyze < %s | FileCheck %s
+
+;   for (unsigned i = 0; i < 100; i++) {
+;     A[i+8] = B[i] + 2;
+;     C[i] = A[i] * 2;
+;   }
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+
+define void @f(i32* %A, i32* %B, i32* %C, i64 %N) {
+
+; CHECK: Interesting Dependences:
+; CHECK-NEXT: Forward:
+; CHECK-NEXT:   store i32 %a_p1, i32* %Aidx_ahead, align 4 ->
+; CHECK-NEXT:   %a = load i32, i32* %Aidx, align 4
+
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %for.body, %entry
+  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+
+  %idx = add nuw nsw i64 %indvars.iv, 8
+
+  %Aidx_ahead = getelementptr inbounds i32, i32* %A, i64 %idx
+  %Bidx = getelementptr inbounds i32, i32* %B, i64 %indvars.iv
+  %Cidx = getelementptr inbounds i32, i32* %C, i64 %indvars.iv
+  %Aidx = getelementptr inbounds i32, i32* %A, i64 %indvars.iv
+
+  %b = load i32, i32* %Bidx, align 4
+  %a_p1 = add i32 %b, 2
+  store i32 %a_p1, i32* %Aidx_ahead, align 4
+
+  %a = load i32, i32* %Aidx, align 4
+  %c = mul i32 %a, 2
+  store i32 %c, i32* %Cidx, align 4
+
+  %exitcond = icmp eq i64 %indvars.iv.next, %N
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:                                          ; preds = %for.body
+  ret void
+}


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D13254.39099.patch
Type: text/x-patch
Size: 3220 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20151103/06c0b73c/attachment.bin>