Disable the main feature of 130180, the elimination of loads that are
redundant with partially-aliasing loads.
When computing what portion of a clobbering load value is needed,
it doesn't consider phi-translation which may have occurred
between the clobbing load and the redundant load.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132631 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/MemoryDependenceAnalysis.cpp b/lib/Analysis/MemoryDependenceAnalysis.cpp
index a412425..5f640c0 100644
--- a/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -374,10 +374,16 @@
if (R == AliasAnalysis::MustAlias)
return MemDepResult::getDef(Inst);
+#if 0 // FIXME: Temporarily disabled. GVN is cleverly rewriting loads
+ // in terms of clobbering loads, but since it does this by looking
+ // at the clobbering load directly, it doesn't know about any
+ // phi translation that may have happened along the way.
+
// If we have a partial alias, then return this as a clobber for the
// client to handle.
if (R == AliasAnalysis::PartialAlias)
return MemDepResult::getClobber(Inst);
+#endif
// Random may-alias loads don't depend on each other without a
// dependence.
diff --git a/test/Transforms/GVN/rle.ll b/test/Transforms/GVN/rle.ll
index 51f2727..28b1fc7 100644
--- a/test/Transforms/GVN/rle.ll
+++ b/test/Transforms/GVN/rle.ll
@@ -562,14 +562,14 @@
%add = add nsw i32 %tmp2, %conv
ret i32 %add
-; CHECK: @load_load_partial_alias
-; CHECK: load i32*
-; CHECK-NOT: load
-; CHECK: lshr i32 {{.*}}, 8
-; CHECK-NOT: load
-; CHECK: trunc i32 {{.*}} to i8
-; CHECK-NOT: load
-; CHECK: ret i32
+; TEMPORARILYDISABLED: @load_load_partial_alias
+; TEMPORARILYDISABLED: load i32*
+; TEMPORARILYDISABLED-NOT: load
+; TEMPORARILYDISABLED: lshr i32 {{.*}}, 8
+; TEMPORARILYDISABLED-NOT: load
+; TEMPORARILYDISABLED: trunc i32 {{.*}} to i8
+; TEMPORARILYDISABLED-NOT: load
+; TEMPORARILYDISABLED: ret i32
}
@@ -589,10 +589,10 @@
if.end:
ret i32 52
-; CHECK: @load_load_partial_alias_cross_block
-; CHECK: land.lhs.true:
-; CHECK-NOT: load i8
-; CHECK: ret i32 %conv6
+; TEMPORARILY_DISABLED: @load_load_partial_alias_cross_block
+; TEMPORARILY_DISABLED: land.lhs.true:
+; TEMPORARILY_DISABLED-NOT: load i8
+; TEMPORARILY_DISABLED: ret i32 %conv6
}