Commited patch from Björn Steinbrink:

Summary:
Different range metadata can lead to different optimizations in later
passes, possibly breaking the semantics of the merged function. So range
metadata must be taken into consideration when comparing Load
instructions.

Thanks!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211391 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/IPO/MergeFunctions.cpp b/lib/Transforms/IPO/MergeFunctions.cpp
index c9b4af769136dddf1ac4fd430f09d2136642758f..c66df600700b06e8094687651137af21dcc31155 100644 (file)
--- a/lib/Transforms/IPO/MergeFunctions.cpp
+++ b/lib/Transforms/IPO/MergeFunctions.cpp
@@ -325,6 +325,7 @@ private:
   /// 6.1.Load: volatile (as boolean flag)
   /// 6.2.Load: alignment (as integer numbers)
   /// 6.3.Load: synch-scope (as integer numbers)
+  /// 6.4.Load: range metadata (as integer numbers)
   /// On this stage its better to see the code, since its not more than 10-15
   /// strings for particular instruction, and could change sometimes.
   int cmpOperation(const Instruction *L, const Instruction *R) const;
@@ -788,7 +789,11 @@ int FunctionComparator::cmpOperation(const Instruction *L,
     if (int Res =
             cmpNumbers(LI->getOrdering(), cast<LoadInst>(R)->getOrdering()))
       return Res;
-    return cmpNumbers(LI->getSynchScope(), cast<LoadInst>(R)->getSynchScope());
+    if (int Res =
+            cmpNumbers(LI->getSynchScope(), cast<LoadInst>(R)->getSynchScope()))
+      return Res;
+    return cmpNumbers((uint64_t)LI->getMetadata(LLVMContext::MD_range),
+                      (uint64_t)cast<LoadInst>(R)->getMetadata(LLVMContext::MD_range));
   }
   if (const StoreInst *SI = dyn_cast<StoreInst>(L)) {
     if (int Res =

diff --git a/test/Transforms/MergeFunc/ranges.ll b/test/Transforms/MergeFunc/ranges.ll
new file mode 100644 (file)
index 0000000..e25ff1d
--- /dev/null
+++ b/test/Transforms/MergeFunc/ranges.ll
@@ -0,0 +1,43 @@
+; RUN: opt -mergefunc -S < %s | FileCheck %s
+define i1 @cmp_with_range(i8*, i8*) {
+  %v1 = load i8* %0, !range !0
+  %v2 = load i8* %1, !range !0
+  %out = icmp eq i8 %v1, %v2
+  ret i1 %out
+}
+
+define i1 @cmp_no_range(i8*, i8*) {
+; CHECK-LABEL: @cmp_no_range
+; CHECK-NEXT  %v1 = load i8* %0
+; CHECK-NEXT  %v2 = load i8* %1
+; CHECK-NEXT  %out = icmp eq i8 %v1, %v2
+; CHECK-NEXT  ret i1 %out
+  %v1 = load i8* %0
+  %v2 = load i8* %1
+  %out = icmp eq i8 %v1, %v2
+  ret i1 %out
+}
+
+define i1 @cmp_different_range(i8*, i8*) {
+; CHECK-LABEL: @cmp_different_range
+; CHECK-NEXT:  %v1 = load i8* %0, !range !1
+; CHECK-NEXT:  %v2 = load i8* %1, !range !1
+; CHECK-NEXT:  %out = icmp eq i8 %v1, %v2
+; CHECK-NEXT:  ret i1 %out
+  %v1 = load i8* %0, !range !1
+  %v2 = load i8* %1, !range !1
+  %out = icmp eq i8 %v1, %v2
+  ret i1 %out
+}
+
+define i1 @cmp_with_same_range(i8*, i8*) {
+; CHECK-LABEL: @cmp_with_same_range
+; CHECK: tail call i1 @cmp_with_range
+  %v1 = load i8* %0, !range !0
+  %v2 = load i8* %1, !range !0
+  %out = icmp eq i8 %v1, %v2
+  ret i1 %out
+}
+
+!0 = metadata !{i8 0, i8 2}
+!1 = metadata !{i8 5, i8 7}