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| author | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2011-12-19 16:53:37 +0000 |
|---|---|---|
| committer | Jakob Stoklund Olesen <stoklund@2pi.dk> | 2011-12-19 16:53:37 +0000 |
| commit | 0488d6ee5deed63cc46efb5931d5761ab6f9c64c (patch) | |
| tree | f120a612ac730035572514402256a185d81fe075 /lib/CodeGen/MachineRegisterInfo.cpp | |
| parent | 570f9a972e02830d1ca223743dd6b4cc4fdf9549 (diff) | |
| download | llvm-0488d6ee5deed63cc46efb5931d5761ab6f9c64c.tar.gz llvm-0488d6ee5deed63cc46efb5931d5761ab6f9c64c.tar.bz2 llvm-0488d6ee5deed63cc46efb5931d5761ab6f9c64c.tar.xz | |
Handle sub-register operands in recomputeRegClass().
Now that getMatchingSuperRegClass() returns accurate results, it can be
used to compute constraints imposed by instructions using a sub-register
of a virtual register.
This means we can recompute the register class of any virtual register
by combining the constraints from all its uses.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146874 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/MachineRegisterInfo.cpp')
| -rw-r--r-- | lib/CodeGen/MachineRegisterInfo.cpp | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp index 266ebf64a3..c35b154aa1 100644 --- a/lib/CodeGen/MachineRegisterInfo.cpp +++ b/lib/CodeGen/MachineRegisterInfo.cpp @@ -76,12 +76,14 @@ MachineRegisterInfo::recomputeRegClass(unsigned Reg, const TargetMachine &TM) { // Accumulate constraints from all uses. for (reg_nodbg_iterator I = reg_nodbg_begin(Reg), E = reg_nodbg_end(); I != E; ++I) { - // TRI doesn't have accurate enough information to model this yet. - if (I.getOperand().getSubReg()) - return false; const TargetRegisterClass *OpRC = I->getRegClassConstraint(I.getOperandNo(), TII, TRI); - if (OpRC) + if (unsigned SubIdx = I.getOperand().getSubReg()) { + if (OpRC) + NewRC = TRI->getMatchingSuperRegClass(NewRC, OpRC, SubIdx); + else + NewRC = TRI->getSubClassWithSubReg(NewRC, SubIdx); + } else if (OpRC) NewRC = TRI->getCommonSubClass(NewRC, OpRC); if (!NewRC || NewRC == OldRC) return false; |