PR14896: Handle memcpy from constant string where the memcpy size is larger than...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172124 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 6c29c67808eba8a7040d308508379b4b551972e0..344d1447a8de485dff41954f570490d81e09cc73 100644 (file)
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -3374,10 +3374,11 @@ static SDValue getMemsetStringVal(EVT VT, DebugLoc dl, SelectionDAG &DAG,
   }
 
   assert(!VT.isVector() && "Can't handle vector type here!");
-  unsigned NumVTBytes = VT.getSizeInBits() / 8;
+  unsigned NumVTBits = VT.getSizeInBits();
+  unsigned NumVTBytes = NumVTBits / 8;
   unsigned NumBytes = std::min(NumVTBytes, unsigned(Str.size()));
 
-  APInt Val(NumBytes*8, 0);
+  APInt Val(NumVTBits, 0);
   if (TLI.isLittleEndian()) {
     for (unsigned i = 0; i != NumBytes; ++i)
       Val |= (uint64_t)(unsigned char)Str[i] << i*8;

diff --git a/test/CodeGen/X86/memcpy.ll b/test/CodeGen/X86/memcpy.ll
index 39c7fbafd4c7b6c7501a5779d0aadb8b1740d53f..2e02e45c8ddfee9e41e09291756d9cc8e6e3c64a 100644 (file)
--- a/test/CodeGen/X86/memcpy.ll
+++ b/test/CodeGen/X86/memcpy.ll
@@ -87,8 +87,21 @@ entry:
   tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* %C, i8* getelementptr inbounds ([30 x i8]* @.str, i64 0, i64 0), i64 16, i32 1, i1 false)
   ret void
 
+; DARWIN: test5:
 ; DARWIN: movabsq      $7016996765293437281
 ; DARWIN: movabsq      $7016996765293437184
 }
 
 
+; PR14896
+@.str2 = private unnamed_addr constant [2 x i8] c"x\00", align 1
+
+define void @test6() nounwind uwtable {
+entry:
+; DARWIN: test6
+; DARWIN: movw $0, 8
+; DARWIN: movq $120, 0
+  tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* null, i8* getelementptr inbounds ([2 x i8]* @.str2, i64 0, i64 0), i64 10, i32 1, i1 false)
+  ret void
+}
+