PVS-Studio noticed that EmitVBR64 would perform undefined behaviour if the

number of bits was bigger than 32.  I checked every use of this function
that I could find and it looks like the maximum number of bits is 32, so I've
added an assertion checking this property, and a type cast to (hopefully) stop
PVS-Studio from warning about this in the future.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162277 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Duncan Sands 2012-08-21 13:47:25 +00:00
parent d43d7fec10
commit 91fcb7f420

View File

@ -155,6 +155,7 @@ public:
}
void EmitVBR(uint32_t Val, unsigned NumBits) {
assert(NumBits <= 32 && "Too many bits to emit!");
uint32_t Threshold = 1U << (NumBits-1);
// Emit the bits with VBR encoding, NumBits-1 bits at a time.
@ -167,10 +168,11 @@ public:
}
void EmitVBR64(uint64_t Val, unsigned NumBits) {
assert(NumBits <= 32 && "Too many bits to emit!");
if ((uint32_t)Val == Val)
return EmitVBR((uint32_t)Val, NumBits);
uint64_t Threshold = 1U << (NumBits-1);
uint64_t Threshold = uint64_t(1U << (NumBits-1));
// Emit the bits with VBR encoding, NumBits-1 bits at a time.
while (Val >= Threshold) {