Load from GV stub should be locally CSE'd.

llvm-svn: 55763

llvm/lib/Target/X86/X86FastISel.cpp

@@ -71,6 +71,8 @@ bool X86FastISel::X86SelectConstAddr(Value *V,
     X86AddressMode AM;
     AM.GV = GV;
     addFullAddress(BuildMI(MBB, TII.get(Opc), Op0), AM);
+    // Prevent loading GV stub multiple times in same MBB.
+    LocalValueMap[V] = Op0;
   }
   return true;
 }

llvm/test/CodeGen/X86/fast-isel-mem.ll

@@ -0,0 +1,12 @@
+; RUN: llvm-as < %s | llc -fast-isel -mtriple=i386-apple-darwin -mattr=sse2 | \
+; RUN:   grep mov | grep lazy_ptr | count 1
+
+@src = external global i32
+
+define i32 @loadgv() nounwind {
+entry:
+	%0 = load i32* @src, align 4
+	%1 = load i32* @src, align 4
+        %2 = add i32 %0, %1
+	ret i32 %2
+}

llvm/test/CodeGen/X86/fast-isel.ll

@@ -47,11 +47,3 @@ entry:
 	%tmp2 = bitcast i32 0 to i32
 	ret i32 %tmp2
 }
-
-@src = external global i32
-
-define i32 @loadgv() nounwind {
-entry:
-	%0 = load i32* @src, align 4
-	ret i32 %0
-}