diff options
| author | Evan Cheng <evan.cheng@apple.com> | 2011-06-15 01:12:31 +0000 |
|---|---|---|
| committer | Evan Cheng <evan.cheng@apple.com> | 2011-06-15 01:12:31 +0000 |
| commit | bf188aeae7a579fb71480be7d32a2edc4d56d827 (patch) | |
| tree | bb4fb35062d992f7249a8027f3cd0fa869615a60 /lib | |
| parent | cf886188fb04d9521db39fe5213df1295673f51e (diff) | |
| download | llvm-bf188aeae7a579fb71480be7d32a2edc4d56d827.tar.gz llvm-bf188aeae7a579fb71480be7d32a2edc4d56d827.tar.bz2 llvm-bf188aeae7a579fb71480be7d32a2edc4d56d827.tar.xz | |
PerformBFICombine - (bfi A, (and B, Mask1), Mask2) -> (bfi A, B, Mask2) iff
the bits being cleared by the AND are not demanded by the BFI.
The previous BFI dag combine rule was actually incorrect (or used to be
correct until BFI representation changed).
rdar://9609030
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133034 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Target/ARM/ARMISelLowering.cpp | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp index c4513fd97d..358eb597cc 100644 --- a/lib/Target/ARM/ARMISelLowering.cpp +++ b/lib/Target/ARM/ARMISelLowering.cpp @@ -5976,8 +5976,8 @@ static SDValue PerformORCombine(SDNode *N, return SDValue(); } -/// PerformBFICombine - (bfi A, (and B, C1), C2) -> (bfi A, B, C2) iff -/// C1 & C2 == C1. +/// PerformBFICombine - (bfi A, (and B, Mask1), Mask2) -> (bfi A, B, Mask2) iff +/// the bits being cleared by the AND are not demanded by the BFI. static SDValue PerformBFICombine(SDNode *N, TargetLowering::DAGCombinerInfo &DCI) { SDValue N1 = N->getOperand(1); @@ -5985,9 +5985,12 @@ static SDValue PerformBFICombine(SDNode *N, ConstantSDNode *N11C = dyn_cast<ConstantSDNode>(N1.getOperand(1)); if (!N11C) return SDValue(); - unsigned Mask = cast<ConstantSDNode>(N->getOperand(2))->getZExtValue(); + unsigned InvMask = cast<ConstantSDNode>(N->getOperand(2))->getZExtValue(); + unsigned LSB = CountTrailingZeros_32(~InvMask); + unsigned Width = (32 - CountLeadingZeros_32(~InvMask)) - LSB; + unsigned Mask = (1 << Width)-1; unsigned Mask2 = N11C->getZExtValue(); - if ((Mask & Mask2) == Mask2) + if ((Mask & (~Mask2)) == 0) return DCI.DAG.getNode(ARMISD::BFI, N->getDebugLoc(), N->getValueType(0), N->getOperand(0), N1.getOperand(0), N->getOperand(2)); |