diff options
| author | Ulrich Weigand <ulrich.weigand@de.ibm.com> | 2017-12-05 19:42:07 +0000 |
|---|---|---|
| committer | Ulrich Weigand <ulrich.weigand@de.ibm.com> | 2017-12-05 19:42:07 +0000 |
| commit | b7cbf75ecd793d089910775035fc226c7b1a20da (patch) | |
| tree | e7f97ec199df80cf821690891f80a96b99677fa5 /lib/Target/SystemZ | |
| parent | 952471eaa55401f25188e0c158fb59bbdd1586ce (diff) | |
[SystemZ] Validate shifted compare value in adjustForTestUnderMask
When folding a shift into a test-under-mask comparison, make sure that
there is no loss of precision when creating the shifted comparison
value. This usually never happens, except for certain always-true
comparisons in unoptimized code.
Fixes PR35529.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319818 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/SystemZ')
| -rw-r--r-- | lib/Target/SystemZ/SystemZISelLowering.cpp | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/lib/Target/SystemZ/SystemZISelLowering.cpp b/lib/Target/SystemZ/SystemZISelLowering.cpp index ad14e5e34e2..c239cd5ad46 100644 --- a/lib/Target/SystemZ/SystemZISelLowering.cpp +++ b/lib/Target/SystemZ/SystemZISelLowering.cpp @@ -2201,6 +2201,7 @@ static void adjustForTestUnderMask(SelectionDAG &DAG, const SDLoc &DL, NewC.Op0.getOpcode() == ISD::SHL && isSimpleShift(NewC.Op0, ShiftVal) && (MaskVal >> ShiftVal != 0) && + ((CmpVal >> ShiftVal) << ShiftVal) == CmpVal && (NewCCMask = getTestUnderMaskCond(BitSize, NewC.CCMask, MaskVal >> ShiftVal, CmpVal >> ShiftVal, @@ -2211,6 +2212,7 @@ static void adjustForTestUnderMask(SelectionDAG &DAG, const SDLoc &DL, NewC.Op0.getOpcode() == ISD::SRL && isSimpleShift(NewC.Op0, ShiftVal) && (MaskVal << ShiftVal != 0) && + ((CmpVal << ShiftVal) >> ShiftVal) == CmpVal && (NewCCMask = getTestUnderMaskCond(BitSize, NewC.CCMask, MaskVal << ShiftVal, CmpVal << ShiftVal, |