6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-13 20:32:21 +00:00
Code Issues Projects Releases Wiki Activity

ValueTracking: Make computeKnownBits for Arguments a little more clear

Browse Source 
We would sometimes leave the out-param APInts untouched while going
through computeKnownBits.  While I don't know of a way to trigger a bug
involving this in practice, it goes against the overall design of
computeKnownBits.

Found via code inspection.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225109 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
David Majnemer 2015-01-03 02:33:25 +00:00
parent 958b670c34
commit ef8f7e1a5a
1 changed files with 3 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
lib/Analysis/ValueTracking.cpp
View File

@ -831,6 +831,9 @@ void computeKnownBits(Value *V, APInt &KnownZero, APInt &KnownOne,
if (Align)
KnownZero = APInt::getLowBitsSet(BitWidth, countTrailingZeros(Align));
else
KnownZero.clearAllBits();
KnownOne.clearAllBits();
// Don't give up yet... there might be an assumption that provides more
// information...