fix infinite loop in instcombine with more than 4GB memcpy
- memcpy size is wrongly truncated into 32-bit and treat 8GB memcpy is
0-sized memcpy
- as 0-sized memcpy/memset is already removed before SimplifyMemTransfer
and SimplifyMemSet in visitCallInst, replace 0 checking with
assertions.
- replace getZExtValue() with getLimitedValue() according to
Eli Friedman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161923 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp
index d34fab1..cbe1ca4 100644
--- a/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -51,8 +51,8 @@
// if the size is something we can handle with a single primitive load/store.
// A single load+store correctly handles overlapping memory in the memmove
// case.
- unsigned Size = MemOpLength->getZExtValue();
- if (Size == 0) return MI; // Delete this mem transfer.
+ uint64_t Size = MemOpLength->getLimitedValue();
+ assert(Size && "0-sized memory transfering should be removed already.");
if (Size > 8 || (Size&(Size-1)))
return 0; // If not 1/2/4/8 bytes, exit.
@@ -133,11 +133,9 @@
ConstantInt *FillC = dyn_cast<ConstantInt>(MI->getValue());
if (!LenC || !FillC || !FillC->getType()->isIntegerTy(8))
return 0;
- uint64_t Len = LenC->getZExtValue();
+ uint64_t Len = LenC->getLimitedValue();
Alignment = MI->getAlignment();
-
- // If the length is zero, this is a no-op
- if (Len == 0) return MI; // memset(d,c,0,a) -> noop
+ assert(Len && "0-sized memory setting should be removed already.");
// memset(s,c,n) -> store s, c (for n=1,2,4,8)
if (Len <= 8 && isPowerOf2_32((uint32_t)Len)) {