[llvm] r295038 - [LoopVectorize] Added address space check when analysing interleaved accesses

[Karl-Johan Karlsson via llvm-commits]

Author: karka
Date: Tue Feb 14 02:14:06 2017
New Revision: 295038

URL: http://llvm.org/viewvc/llvm-project?rev=295038&view=rev
Log:
[LoopVectorize] Added address space check when analysing interleaved accesses

Prevent memory objects of different address spaces to be part of
the same load/store groups when analysing interleaved accesses.

This is fixing pr31900.

Reviewers: HaoLiu, mssimpso, mkuper

Reviewed By: mssimpso, mkuper

Subscribers: llvm-commits, efriedma, mzolotukhin

Differential Revision: https://reviews.llvm.org/D29717

Added:
    llvm/trunk/test/Transforms/LoopVectorize/AArch64/pr31900.ll
Modified:
    llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp

Modified: llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp?rev=295038&r1=295037&r2=295038&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/LoopVectorize.cpp Tue Feb 14 02:14:06 2017
@@ -5997,6 +5997,12 @@ void InterleavedAccessInfo::analyzeInter
       if (DesA.Stride != DesB.Stride || DesA.Size != DesB.Size)
         continue;
 
+      // Ignore A if the memory object of A and B don't belong to the same
+      // address space
+      if (DesA.Scev->getType()->getPointerAddressSpace() !=
+          DesB.Scev->getType()->getPointerAddressSpace())
+        continue;
+
       // Calculate the distance from A to B.
       const SCEVConstant *DistToB = dyn_cast<SCEVConstant>(
           PSE.getSE()->getMinusSCEV(DesA.Scev, DesB.Scev));
@@ -6040,35 +6046,35 @@ void InterleavedAccessInfo::analyzeInter
       releaseGroup(Group);
 
   // Remove interleaved groups with gaps (currently only loads) whose memory
-  // accesses may wrap around. We have to revisit the getPtrStride analysis, 
-  // this time with ShouldCheckWrap=true, since collectConstStrideAccesses does 
+  // accesses may wrap around. We have to revisit the getPtrStride analysis,
+  // this time with ShouldCheckWrap=true, since collectConstStrideAccesses does
   // not check wrapping (see documentation there).
-  // FORNOW we use Assume=false; 
-  // TODO: Change to Assume=true but making sure we don't exceed the threshold 
+  // FORNOW we use Assume=false;
+  // TODO: Change to Assume=true but making sure we don't exceed the threshold
   // of runtime SCEV assumptions checks (thereby potentially failing to
-  // vectorize altogether). 
+  // vectorize altogether).
   // Additional optional optimizations:
-  // TODO: If we are peeling the loop and we know that the first pointer doesn't 
+  // TODO: If we are peeling the loop and we know that the first pointer doesn't
   // wrap then we can deduce that all pointers in the group don't wrap.
-  // This means that we can forcefully peel the loop in order to only have to 
-  // check the first pointer for no-wrap. When we'll change to use Assume=true 
+  // This means that we can forcefully peel the loop in order to only have to
+  // check the first pointer for no-wrap. When we'll change to use Assume=true
   // we'll only need at most one runtime check per interleaved group.
   //
   for (InterleaveGroup *Group : LoadGroups) {
 
     // Case 1: A full group. Can Skip the checks; For full groups, if the wide
-    // load would wrap around the address space we would do a memory access at 
-    // nullptr even without the transformation. 
-    if (Group->getNumMembers() == Group->getFactor()) 
+    // load would wrap around the address space we would do a memory access at
+    // nullptr even without the transformation.
+    if (Group->getNumMembers() == Group->getFactor())
       continue;
 
-    // Case 2: If first and last members of the group don't wrap this implies 
+    // Case 2: If first and last members of the group don't wrap this implies
     // that all the pointers in the group don't wrap.
     // So we check only group member 0 (which is always guaranteed to exist),
-    // and group member Factor - 1; If the latter doesn't exist we rely on 
+    // and group member Factor - 1; If the latter doesn't exist we rely on
     // peeling (if it is a non-reveresed accsess -- see Case 3).
     Value *FirstMemberPtr = getPointerOperand(Group->getMember(0));
-    if (!getPtrStride(PSE, FirstMemberPtr, TheLoop, Strides, /*Assume=*/false, 
+    if (!getPtrStride(PSE, FirstMemberPtr, TheLoop, Strides, /*Assume=*/false,
                       /*ShouldCheckWrap=*/true)) {
       DEBUG(dbgs() << "LV: Invalidate candidate interleaved group due to "
                       "first group member potentially pointer-wrapping.\n");

Added: llvm/trunk/test/Transforms/LoopVectorize/AArch64/pr31900.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopVectorize/AArch64/pr31900.ll?rev=295038&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LoopVectorize/AArch64/pr31900.ll (added)
+++ llvm/trunk/test/Transforms/LoopVectorize/AArch64/pr31900.ll Tue Feb 14 02:14:06 2017
@@ -0,0 +1,37 @@
+; RUN: opt -S -mtriple=aarch64-apple-ios -loop-vectorize -enable-interleaved-mem-accesses -force-vector-width=2 < %s | FileCheck %s
+
+; Reproducer for address space fault in the LoopVectorizer (pr31900). Added
+; different sized address space pointers (p:16:16-p4:32:16) to the aarch64
+; datalayout to reproduce the fault.
+
+target datalayout = "e-m:e-i64:64-i128:128-n32:64-S128-p:16:16-p4:32:16"
+
+; Check that all the loads are scalarized
+; CHECK: load i16, i16*
+; CHECK: load i16, i16*
+; CHECK: load i16, i16 addrspace(4)*
+; CHECK: load i16, i16 addrspace(4)*
+
+%rec1445 = type { i16, i16, i16, i16, i16 }
+
+define void @foo() {
+bb1:
+  br label %bb4
+
+bb4:
+  %tmp1 = phi i16 [ undef, %bb1 ], [ %_tmp1013, %bb4 ]
+  %tmp2 = phi %rec1445* [ undef, %bb1 ], [ %_tmp1015, %bb4 ]
+  %tmp3 = phi %rec1445 addrspace(4)* [ undef, %bb1 ], [ %_tmp1017, %bb4 ]
+  %0 = getelementptr %rec1445, %rec1445* %tmp2, i16 0, i32 1
+  %_tmp987 = load i16, i16* %0, align 1
+  %1 = getelementptr %rec1445, %rec1445 addrspace(4)* %tmp3, i32 0, i32 1
+  %_tmp993 = load i16, i16 addrspace(4)* %1, align 1
+  %_tmp1013 = add i16 %tmp1, 1
+  %_tmp1015 = getelementptr %rec1445, %rec1445* %tmp2, i16 1
+  %_tmp1017 = getelementptr %rec1445, %rec1445 addrspace(4)* %tmp3, i32 1
+  %_tmp1019 = icmp ult i16 %_tmp1013, 24
+  br i1 %_tmp1019, label %bb4, label %bb16
+
+bb16:
+  unreachable
+}