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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172124 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2013-01-10 22:13:27 +00:00
parent 81bfd711de
commit 4ff23d09fa
2 changed files with 16 additions and 2 deletions

View File

@ -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;

View File

@ -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
}