[llvm-branch-commits] [llvm-branch] r89564 - in /llvm/branches/Apple/Zoidberg: include/llvm/Analysis/CaptureTracking.h lib/Analysis/BasicAliasAnalysis.cpp lib/Analysis/CaptureTracking.cpp lib/Transforms/IPO/FunctionAttrs.cpp test/Transforms/GVN/nonescaping-malloc.ll

Bob Wilson bob.wilson at apple.com
Sat Nov 21 14:10:11 PST 2009


Author: bwilson
Date: Sat Nov 21 16:10:10 2009
New Revision: 89564

URL: http://llvm.org/viewvc/llvm-project?rev=89564&view=rev
Log:
Temporarily revert 89389, 89398, 89436, and 89485 from zoidberg.  For some
reason as yet unknown, these changes are causing performance regressions
for ARM.

Modified:
    llvm/branches/Apple/Zoidberg/include/llvm/Analysis/CaptureTracking.h
    llvm/branches/Apple/Zoidberg/lib/Analysis/BasicAliasAnalysis.cpp
    llvm/branches/Apple/Zoidberg/lib/Analysis/CaptureTracking.cpp
    llvm/branches/Apple/Zoidberg/lib/Transforms/IPO/FunctionAttrs.cpp
    llvm/branches/Apple/Zoidberg/test/Transforms/GVN/nonescaping-malloc.ll

Modified: llvm/branches/Apple/Zoidberg/include/llvm/Analysis/CaptureTracking.h
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/Apple/Zoidberg/include/llvm/Analysis/CaptureTracking.h?rev=89564&r1=89563&r2=89564&view=diff

==============================================================================
--- llvm/branches/Apple/Zoidberg/include/llvm/Analysis/CaptureTracking.h (original)
+++ llvm/branches/Apple/Zoidberg/include/llvm/Analysis/CaptureTracking.h Sat Nov 21 16:10:10 2009
@@ -21,12 +21,8 @@
   /// by the enclosing function (which is required to exist).  This routine can
   /// be expensive, so consider caching the results.  The boolean ReturnCaptures
   /// specifies whether returning the value (or part of it) from the function
-  /// counts as capturing it or not.  The boolean StoreCaptures specified whether
-  /// storing the value (or part of it) into memory anywhere automatically
   /// counts as capturing it or not.
-  bool PointerMayBeCaptured(const Value *V,
-                            bool ReturnCaptures,
-                            bool StoreCaptures);
+  bool PointerMayBeCaptured(const Value *V, bool ReturnCaptures);
 
 } // end namespace llvm
 

Modified: llvm/branches/Apple/Zoidberg/lib/Analysis/BasicAliasAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/Apple/Zoidberg/lib/Analysis/BasicAliasAnalysis.cpp?rev=89564&r1=89563&r2=89564&view=diff

==============================================================================
--- llvm/branches/Apple/Zoidberg/lib/Analysis/BasicAliasAnalysis.cpp (original)
+++ llvm/branches/Apple/Zoidberg/lib/Analysis/BasicAliasAnalysis.cpp Sat Nov 21 16:10:10 2009
@@ -79,12 +79,7 @@
 static bool isNonEscapingLocalObject(const Value *V) {
   // If this is a local allocation, check to see if it escapes.
   if (isa<AllocaInst>(V) || isNoAliasCall(V))
-    // Set StoreCaptures to True so that we can assume in our callers that the
-    // pointer is not the result of a load instruction. Currently
-    // PointerMayBeCaptured doesn't have any special analysis for the
-    // StoreCaptures=false case; if it did, our callers could be refined to be
-    // more precise.
-    return !PointerMayBeCaptured(V, false, /*StoreCaptures=*/true);
+    return !PointerMayBeCaptured(V, false);
 
   // If this is an argument that corresponds to a byval or noalias argument,
   // then it has not escaped before entering the function.  Check if it escapes
@@ -94,7 +89,7 @@
       // Don't bother analyzing arguments already known not to escape.
       if (A->hasNoCaptureAttr())
         return true;
-      return !PointerMayBeCaptured(V, false, /*StoreCaptures=*/true);
+      return !PointerMayBeCaptured(V, false);
     }
   return false;
 }
@@ -688,19 +683,15 @@
         (V2Size != ~0U && isObjectSmallerThan(O1, V2Size, *TD)))
       return NoAlias;
   
-  // If one pointer is the result of a call/invoke or load and the other is a
+  // If one pointer is the result of a call/invoke and the other is a
   // non-escaping local object, then we know the object couldn't escape to a
-  // point where the call could return it. The load case works because
-  // isNonEscapingLocalObject considers all stores to be escapes (it
-  // passes true for the StoreCaptures argument to PointerMayBeCaptured).
-  if (O1 != O2) {
-    if ((isa<CallInst>(O1) || isa<InvokeInst>(O1) || isa<LoadInst>(O1)) &&
-        isNonEscapingLocalObject(O2))
-      return NoAlias;
-    if ((isa<CallInst>(O2) || isa<InvokeInst>(O2) || isa<LoadInst>(O2)) &&
-        isNonEscapingLocalObject(O1))
-      return NoAlias;
-  }
+  // point where the call could return it.
+  if ((isa<CallInst>(O1) || isa<InvokeInst>(O1)) &&
+      isNonEscapingLocalObject(O2) && O1 != O2)
+    return NoAlias;
+  if ((isa<CallInst>(O2) || isa<InvokeInst>(O2)) &&
+      isNonEscapingLocalObject(O1) && O1 != O2)
+    return NoAlias;
 
   if (!isa<GEPOperator>(V1) && isa<GEPOperator>(V2)) {
     std::swap(V1, V2);

Modified: llvm/branches/Apple/Zoidberg/lib/Analysis/CaptureTracking.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/Apple/Zoidberg/lib/Analysis/CaptureTracking.cpp?rev=89564&r1=89563&r2=89564&view=diff

==============================================================================
--- llvm/branches/Apple/Zoidberg/lib/Analysis/CaptureTracking.cpp (original)
+++ llvm/branches/Apple/Zoidberg/lib/Analysis/CaptureTracking.cpp Sat Nov 21 16:10:10 2009
@@ -19,7 +19,6 @@
 #include "llvm/Analysis/CaptureTracking.h"
 #include "llvm/Instructions.h"
 #include "llvm/Value.h"
-#include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/CallSite.h"
@@ -29,11 +28,8 @@
 /// by the enclosing function (which is required to exist).  This routine can
 /// be expensive, so consider caching the results.  The boolean ReturnCaptures
 /// specifies whether returning the value (or part of it) from the function
-/// counts as capturing it or not.  The boolean StoreCaptures specified whether
-/// storing the value (or part of it) into memory anywhere automatically
 /// counts as capturing it or not.
-bool llvm::PointerMayBeCaptured(const Value *V,
-                                bool ReturnCaptures, bool StoreCaptures) {
+bool llvm::PointerMayBeCaptured(const Value *V, bool ReturnCaptures) {
   assert(isa<PointerType>(V->getType()) && "Capture is for pointers only!");
   SmallVector<Use*, 16> Worklist;
   SmallSet<Use*, 16> Visited;
@@ -57,7 +53,8 @@
       // Not captured if the callee is readonly, doesn't return a copy through
       // its return value and doesn't unwind (a readonly function can leak bits
       // by throwing an exception or not depending on the input value).
-      if (CS.onlyReadsMemory() && CS.doesNotThrow() && I->getType()->isVoidTy())
+      if (CS.onlyReadsMemory() && CS.doesNotThrow() &&
+          I->getType() == Type::getVoidTy(V->getContext()))
         break;
 
       // Not captured if only passed via 'nocapture' arguments.  Note that
@@ -85,11 +82,7 @@
       break;
     case Instruction::Store:
       if (V == I->getOperand(0))
-        // Stored the pointer - conservatively assume it may be captured.
-        // TODO: If StoreCaptures is not true, we could do Fancy analysis
-        // to determine whether this store is not actually an escape point.
-        // In that case, BasicAliasAnalysis should be updated as well to
-        // take advantage of this.
+        // Stored the pointer - it may be captured.
         return true;
       // Storing to the pointee does not cause the pointer to be captured.
       break;
@@ -105,18 +98,6 @@
           Worklist.push_back(U);
       }
       break;
-    case Instruction::ICmp:
-      // Don't count comparisons of a no-alias return value against null as
-      // captures. This allows us to ignore comparisons of malloc results
-      // with null, for example.
-      if (isNoAliasCall(V->stripPointerCasts()))
-        if (ConstantPointerNull *CPN =
-              dyn_cast<ConstantPointerNull>(I->getOperand(1)))
-          if (CPN->getType()->getAddressSpace() == 0)
-            break;
-      // Otherwise, be conservative. There are crazy ways to capture pointers
-      // using comparisons.
-      return true;
     default:
       // Something else - be conservative and say it is captured.
       return true;

Modified: llvm/branches/Apple/Zoidberg/lib/Transforms/IPO/FunctionAttrs.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/Apple/Zoidberg/lib/Transforms/IPO/FunctionAttrs.cpp?rev=89564&r1=89563&r2=89564&view=diff

==============================================================================
--- llvm/branches/Apple/Zoidberg/lib/Transforms/IPO/FunctionAttrs.cpp (original)
+++ llvm/branches/Apple/Zoidberg/lib/Transforms/IPO/FunctionAttrs.cpp Sat Nov 21 16:10:10 2009
@@ -212,7 +212,7 @@
 
     for (Function::arg_iterator A = F->arg_begin(), E = F->arg_end(); A!=E; ++A)
       if (isa<PointerType>(A->getType()) && !A->hasNoCaptureAttr() &&
-          !PointerMayBeCaptured(A, true, /*StoreCaptures=*/false)) {
+          !PointerMayBeCaptured(A, true)) {
         A->addAttr(Attribute::NoCapture);
         ++NumNoCapture;
         Changed = true;
@@ -280,7 +280,7 @@
           return false;  // Did not come from an allocation.
       }
 
-    if (PointerMayBeCaptured(RetVal, false, /*StoreCaptures=*/false))
+    if (PointerMayBeCaptured(RetVal, false))
       return false;
   }
 

Modified: llvm/branches/Apple/Zoidberg/test/Transforms/GVN/nonescaping-malloc.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/Apple/Zoidberg/test/Transforms/GVN/nonescaping-malloc.ll?rev=89564&r1=89563&r2=89564&view=diff

==============================================================================
--- llvm/branches/Apple/Zoidberg/test/Transforms/GVN/nonescaping-malloc.ll (original)
+++ llvm/branches/Apple/Zoidberg/test/Transforms/GVN/nonescaping-malloc.ll Sat Nov 21 16:10:10 2009
@@ -1,108 +0,0 @@
-; RUN: opt < %s -gvn -stats |& grep {Number of loads deleted}
-; rdar://7363102
-
-; GVN should be able to eliminate load %tmp22.i, because it is redundant with
-; load %tmp8.i. This requires being able to prove that %tmp7.i doesn't
-; alias the malloc'd value %tmp.i20.i.i, which it can do since %tmp7.i
-; is derived from %tmp5.i which is computed from a load, and %tmp.i20.i.i
-; is never stored and does not escape.
-
-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"
-target triple = "x86_64-apple-darwin10.0"
-
-%"struct.llvm::MallocAllocator" = type <{ i8 }>
-%"struct.llvm::StringMap<void*,llvm::MallocAllocator>" = type { %"struct.llvm::StringMapImpl", %"struct.llvm::MallocAllocator" }
-%"struct.llvm::StringMapEntry<void*>" = type { %"struct.llvm::StringMapEntryBase", i8* }
-%"struct.llvm::StringMapEntryBase" = type { i32 }
-%"struct.llvm::StringMapImpl" = type { %"struct.llvm::StringMapImpl::ItemBucket"*, i32, i32, i32, i32 }
-%"struct.llvm::StringMapImpl::ItemBucket" = type { i32, %"struct.llvm::StringMapEntryBase"* }
-%"struct.llvm::StringRef" = type { i8*, i64 }
-
-define %"struct.llvm::StringMapEntry<void*>"* @_Z3fooRN4llvm9StringMapIPvNS_15MallocAllocatorEEEPKc(%"struct.llvm::StringMap<void*,llvm::MallocAllocator>"* %X, i8* %P) ssp {
-entry:
-  %tmp = alloca %"struct.llvm::StringRef", align 8 ; <%"struct.llvm::StringRef"*> [#uses=3]
-  %tmp.i = getelementptr inbounds %"struct.llvm::StringRef"* %tmp, i64 0, i32 0 ; <i8**> [#uses=1]
-  store i8* %P, i8** %tmp.i, align 8
-  %tmp1.i = call i64 @strlen(i8* %P) nounwind readonly ; <i64> [#uses=1]
-  %tmp2.i = getelementptr inbounds %"struct.llvm::StringRef"* %tmp, i64 0, i32 1 ; <i64*> [#uses=1]
-  store i64 %tmp1.i, i64* %tmp2.i, align 8
-  %tmp1 = call %"struct.llvm::StringMapEntry<void*>"* @_ZN4llvm9StringMapIPvNS_15MallocAllocatorEE16GetOrCreateValueERKNS_9StringRefE(%"struct.llvm::StringMap<void*,llvm::MallocAllocator>"* %X, %"struct.llvm::StringRef"* %tmp) ssp ; <%"struct.llvm::StringMapEntry<void*>"*> [#uses=1]
-  ret %"struct.llvm::StringMapEntry<void*>"* %tmp1
-}
-
-declare i64 @strlen(i8* nocapture) nounwind readonly
-
-declare noalias i8* @malloc(i64) nounwind
-
-declare void @llvm.memcpy.i64(i8* nocapture, i8* nocapture, i64, i32) nounwind
-
-declare i32 @_ZN4llvm13StringMapImpl15LookupBucketForENS_9StringRefE(%"struct.llvm::StringMapImpl"*, i64, i64)
-
-define linkonce_odr %"struct.llvm::StringMapEntry<void*>"* @_ZN4llvm9StringMapIPvNS_15MallocAllocatorEE16GetOrCreateValueERKNS_9StringRefE(%"struct.llvm::StringMap<void*,llvm::MallocAllocator>"* %this, %"struct.llvm::StringRef"* nocapture %Key) ssp align 2 {
-entry:
-  %elt = bitcast %"struct.llvm::StringRef"* %Key to i64* ; <i64*> [#uses=1]
-  %val = load i64* %elt                           ; <i64> [#uses=3]
-  %tmp = getelementptr inbounds %"struct.llvm::StringRef"* %Key, i64 0, i32 1 ; <i64*> [#uses=1]
-  %val2 = load i64* %tmp                          ; <i64> [#uses=2]
-  %tmp2.i = getelementptr inbounds %"struct.llvm::StringMap<void*,llvm::MallocAllocator>"* %this, i64 0, i32 0 ; <%"struct.llvm::StringMapImpl"*> [#uses=1]
-  %tmp3.i = tail call i32 @_ZN4llvm13StringMapImpl15LookupBucketForENS_9StringRefE(%"struct.llvm::StringMapImpl"* %tmp2.i, i64 %val, i64 %val2) ; <i32> [#uses=1]
-  %tmp4.i = getelementptr inbounds %"struct.llvm::StringMap<void*,llvm::MallocAllocator>"* %this, i64 0, i32 0, i32 0 ; <%"struct.llvm::StringMapImpl::ItemBucket"**> [#uses=1]
-  %tmp5.i = load %"struct.llvm::StringMapImpl::ItemBucket"** %tmp4.i, align 8 ; <%"struct.llvm::StringMapImpl::ItemBucket"*> [#uses=1]
-  %tmp6.i = zext i32 %tmp3.i to i64               ; <i64> [#uses=1]
-  %tmp7.i = getelementptr inbounds %"struct.llvm::StringMapImpl::ItemBucket"* %tmp5.i, i64 %tmp6.i, i32 1 ; <%"struct.llvm::StringMapEntryBase"**> [#uses=2]
-  %tmp8.i = load %"struct.llvm::StringMapEntryBase"** %tmp7.i, align 8 ; <%"struct.llvm::StringMapEntryBase"*> [#uses=3]
-  %tmp9.i = icmp eq %"struct.llvm::StringMapEntryBase"* %tmp8.i, null ; <i1> [#uses=1]
-  %tmp13.i = icmp eq %"struct.llvm::StringMapEntryBase"* %tmp8.i, inttoptr (i64 -1 to %"struct.llvm::StringMapEntryBase"*) ; <i1> [#uses=1]
-  %or.cond.i = or i1 %tmp9.i, %tmp13.i            ; <i1> [#uses=1]
-  br i1 %or.cond.i, label %bb4.i, label %bb6.i
-
-bb4.i:                                            ; preds = %entry
-  %tmp41.i = inttoptr i64 %val to i8*             ; <i8*> [#uses=2]
-  %tmp4.i35.i = getelementptr inbounds i8* %tmp41.i, i64 %val2 ; <i8*> [#uses=1]
-  %tmp.i.i = ptrtoint i8* %tmp4.i35.i to i64      ; <i64> [#uses=1]
-  %tmp1.i.i = trunc i64 %tmp.i.i to i32           ; <i32> [#uses=1]
-  %tmp3.i.i = trunc i64 %val to i32               ; <i32> [#uses=1]
-  %tmp4.i.i = sub i32 %tmp1.i.i, %tmp3.i.i        ; <i32> [#uses=3]
-  %tmp5.i.i = add i32 %tmp4.i.i, 17               ; <i32> [#uses=1]
-  %tmp8.i.i = zext i32 %tmp5.i.i to i64           ; <i64> [#uses=1]
-  %tmp.i20.i.i = tail call noalias i8* @malloc(i64 %tmp8.i.i) nounwind ; <i8*> [#uses=7]
-  %tmp10.i.i = bitcast i8* %tmp.i20.i.i to %"struct.llvm::StringMapEntry<void*>"* ; <%"struct.llvm::StringMapEntry<void*>"*> [#uses=2]
-  %tmp12.i.i = icmp eq i8* %tmp.i20.i.i, null     ; <i1> [#uses=1]
-  br i1 %tmp12.i.i, label %_ZN4llvm14StringMapEntryIPvE6CreateINS_15MallocAllocatorES1_EEPS2_PKcS7_RT_T0_.exit.i, label %bb.i.i
-
-bb.i.i:                                           ; preds = %bb4.i
-  %tmp.i.i.i.i = bitcast i8* %tmp.i20.i.i to i32* ; <i32*> [#uses=1]
-  store i32 %tmp4.i.i, i32* %tmp.i.i.i.i, align 4
-  %tmp1.i19.i.i = getelementptr inbounds i8* %tmp.i20.i.i, i64 8 ; <i8*> [#uses=1]
-  %0 = bitcast i8* %tmp1.i19.i.i to i8**          ; <i8**> [#uses=1]
-  store i8* null, i8** %0, align 8
-  br label %_ZN4llvm14StringMapEntryIPvE6CreateINS_15MallocAllocatorES1_EEPS2_PKcS7_RT_T0_.exit.i
-
-_ZN4llvm14StringMapEntryIPvE6CreateINS_15MallocAllocatorES1_EEPS2_PKcS7_RT_T0_.exit.i: ; preds = %bb4.i, %bb.i.i
-  %tmp.i18.i.i = getelementptr inbounds i8* %tmp.i20.i.i, i64 16 ; <i8*> [#uses=1]
-  %tmp15.i.i = zext i32 %tmp4.i.i to i64          ; <i64> [#uses=2]
-  tail call void @llvm.memcpy.i64(i8* %tmp.i18.i.i, i8* %tmp41.i, i64 %tmp15.i.i, i32 1) nounwind
-  %tmp.i18.sum.i.i = add i64 %tmp15.i.i, 16       ; <i64> [#uses=1]
-  %tmp17.i.i = getelementptr inbounds i8* %tmp.i20.i.i, i64 %tmp.i18.sum.i.i ; <i8*> [#uses=1]
-  store i8 0, i8* %tmp17.i.i, align 1
-  %tmp.i.i.i = getelementptr inbounds i8* %tmp.i20.i.i, i64 8 ; <i8*> [#uses=1]
-  %1 = bitcast i8* %tmp.i.i.i to i8**             ; <i8**> [#uses=1]
-  store i8* null, i8** %1, align 8
-  %tmp22.i = load %"struct.llvm::StringMapEntryBase"** %tmp7.i, align 8 ; <%"struct.llvm::StringMapEntryBase"*> [#uses=1]
-  %tmp24.i = icmp eq %"struct.llvm::StringMapEntryBase"* %tmp22.i, inttoptr (i64 -1 to %"struct.llvm::StringMapEntryBase"*) ; <i1> [#uses=1]
-  br i1 %tmp24.i, label %bb9.i, label %_ZN4llvm9StringMapIPvNS_15MallocAllocatorEE16GetOrCreateValueIS1_EERNS_14StringMapEntryIS1_EENS_9StringRefET_.exit
-
-bb6.i:                                            ; preds = %entry
-  %tmp16.i = bitcast %"struct.llvm::StringMapEntryBase"* %tmp8.i to %"struct.llvm::StringMapEntry<void*>"* ; <%"struct.llvm::StringMapEntry<void*>"*> [#uses=1]
-  ret %"struct.llvm::StringMapEntry<void*>"* %tmp16.i
-
-bb9.i:                                            ; preds = %_ZN4llvm14StringMapEntryIPvE6CreateINS_15MallocAllocatorES1_EEPS2_PKcS7_RT_T0_.exit.i
-  %tmp25.i = getelementptr inbounds %"struct.llvm::StringMap<void*,llvm::MallocAllocator>"* %this, i64 0, i32 0, i32 3 ; <i32*> [#uses=2]
-  %tmp26.i = load i32* %tmp25.i, align 8          ; <i32> [#uses=1]
-  %tmp27.i = add i32 %tmp26.i, -1                 ; <i32> [#uses=1]
-  store i32 %tmp27.i, i32* %tmp25.i, align 8
-  ret %"struct.llvm::StringMapEntry<void*>"* %tmp10.i.i
-
-_ZN4llvm9StringMapIPvNS_15MallocAllocatorEE16GetOrCreateValueIS1_EERNS_14StringMapEntryIS1_EENS_9StringRefET_.exit: ; preds = %_ZN4llvm14StringMapEntryIPvE6CreateINS_15MallocAllocatorES1_EEPS2_PKcS7_RT_T0_.exit.i
-  ret %"struct.llvm::StringMapEntry<void*>"* %tmp10.i.i
-}





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