Implement PR2370: memmove(x,x,size) -> noop.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51636 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2008-05-28 05:30:41 +00:00
parent e5ab3355ba
commit a935db8ea2
2 changed files with 10 additions and 0 deletions

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@ -9131,6 +9131,10 @@ Instruction *InstCombiner::visitCallInst(CallInst &CI) {
CI.setOperand(0, Intrinsic::getDeclaration(M, MemCpyID));
Changed = true;
}
// memmove(x,x,size) -> noop.
if (MMI->getSource() == MMI->getDest())
return EraseInstFromFunction(CI);
}
// If we can determine a pointer alignment that is bigger than currently

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@ -34,3 +34,9 @@ define i32 @test3() {
ret i32 0
}
; PR2370
define void @test4(i8* %a) {
tail call void @llvm.memmove.i32( i8* %a, i8* %a, i32 100, i32 1 )
ret void
}