Revert r121520, which may have introduced miscompilations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121573 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 2 insertions, 38 deletions

diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 17a502e1f7..3ab18fd3c0 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -857,17 +857,6 @@ BasicAliasAnalysis::aliasGEP(const GEPOperator *GEP1, uint64_t V1Size,
   if (GEP1BaseOffset == 0 && GEP1VariableIndices.empty())
     return MustAlias;
 
-  // If there is a difference betwen the pointers, but the difference is
-  // less than the size of the associated memory object, then we know
-  // that the objects are partially overlapping.
-  if (GEP1BaseOffset != 0 && GEP1VariableIndices.empty()) {
-    if (GEP1BaseOffset >= 0 ?
-        (V2Size != UnknownSize && (uint64_t)GEP1BaseOffset < V2Size) :
-        (V1Size != UnknownSize && -(uint64_t)GEP1BaseOffset < V1Size &&
-         GEP1BaseOffset != INT64_MIN))
-      return PartialAlias;
-  }
-
   // If we have a known constant offset, see if this offset is larger than the
   // access size being queried.  If so, and if no variable indices can remove
   // pieces of this constant, then we know we have a no-alias.  For example,
diff --git a/test/Analysis/TypeBasedAliasAnalysis/precedence.ll b/test/Analysis/TypeBasedAliasAnalysis/precedence.ll
index ade39f7c8e..9fa859eaab 100644
--- a/test/Analysis/TypeBasedAliasAnalysis/precedence.ll
+++ b/test/Analysis/TypeBasedAliasAnalysis/precedence.ll
@@ -1,5 +1,5 @@
-; RUN: opt -enable-tbaa -basicaa -tbaa -gvn -instcombine -S < %s | FileCheck %s --check-prefix=TBAA
-; RUN: opt -enable-tbaa -tbaa -basicaa -gvn -instcombine -S < %s | FileCheck %s --check-prefix=BASICAA
+; RUN: opt -enable-tbaa -basicaa -tbaa -gvn -instcombine -S < %s | grep {ret i32 0}
+; RUN: opt -enable-tbaa -tbaa -basicaa -gvn -instcombine -S < %s | grep {ret i32 1075000115}
 
 ; According to the TBAA metadata the load and store don't alias. However,
 ; according to the actual code, they do. The order of the alias analysis
@@ -7,12 +7,6 @@
 
 target datalayout = "e-p:64:64:64"
 
-; Test for simple MustAlias aliasing.
-
-; TBAA:    @trouble
-; TBAA:      ret i32 0
-; BASICAA: @trouble
-; BASICAA:   ret i32 1075000115
 define i32 @trouble(i32* %x) nounwind {
 entry:
   store i32 0, i32* %x, !tbaa !0
@@ -22,25 +16,6 @@ entry:
   ret i32 %tmp3
 }
 
-; Test for PartialAlias aliasing. GVN doesn't yet eliminate the load
-; in the BasicAA case.
-
-; TBAA:    @offset
-; TBAA:      ret i64 0
-; BASICAA: @offset
-; BASICAA:   ret i64 %tmp3
-define i64 @offset(i64* %x) nounwind {
-entry:
-  store i64 0, i64* %x, !tbaa !4
-  %0 = bitcast i64* %x to i8*
-  %1 = getelementptr i8* %0, i64 1
-  store i8 1, i8* %1, !tbaa !5
-  %tmp3 = load i64* %x, !tbaa !4
-  ret i64 %tmp3
-}
-
 !0 = metadata !{metadata !"int", metadata !1}
 !1 = metadata !{metadata !"simple"}
 !3 = metadata !{metadata !"float", metadata !1}
-!4 = metadata !{metadata !"long", metadata !1}
-!5 = metadata !{metadata !"small", metadata !1}