diff options
author | Jonas Paulsson <paulsson@linux.vnet.ibm.com> | 2017-12-04 10:03:14 +0000 |
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committer | Jonas Paulsson <paulsson@linux.vnet.ibm.com> | 2017-12-04 10:03:14 +0000 |
commit | 62f11d908ed4e9b576d6769cfdbce3e215c40cd1 (patch) | |
tree | 83a165afbf0fd1bfdc18f21d614deb825540b199 /lib/CodeGen/TwoAddressInstructionPass.cpp | |
parent | 5022455191e0d386d601770f5ea936f6376d21f9 (diff) |
[TwoAddressInstructionPass] Bugfix in handling of sunk instructions.
An instruction returned by TII->convertToThreeAddress() may contain a %noreg
(undef) operand, which is not expected by tryInstructionTransform(). So if
this MI is sunk to a lower point in MBB, it must be skipped when later
encountered.
A new set SunkInstrs is used for this purpose.
Note: there is no test supplied here, as this was triggered on SystemZ while
working on a review of instruction flags. A test case for this bugfix will be
included in the upcoming SystemZ commit.
Review: Quentin Colombet
https://reviews.llvm.org/D40711
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319646 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/TwoAddressInstructionPass.cpp')
-rw-r--r-- | lib/CodeGen/TwoAddressInstructionPass.cpp | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp index b996850d706..28a4375cb28 100644 --- a/lib/CodeGen/TwoAddressInstructionPass.cpp +++ b/lib/CodeGen/TwoAddressInstructionPass.cpp @@ -110,6 +110,10 @@ class TwoAddressInstructionPass : public MachineFunctionPass { // Set of already processed instructions in the current block. SmallPtrSet<MachineInstr*, 8> Processed; + // Set of instructions converted to three-address by target and then sunk + // down current basic block. + SmallPtrSet<MachineInstr*, 8> SunkInstrs; + // A map from virtual registers to physical registers which are likely targets // to be coalesced to due to copies from physical registers to virtual // registers. e.g. v1024 = move r0. @@ -756,6 +760,8 @@ TwoAddressInstructionPass::convertInstTo3Addr(MachineBasicBlock::iterator &mi, mi = NewMI; nmi = std::next(mi); } + else + SunkInstrs.insert(NewMI); // Update source and destination register maps. SrcRegMap.erase(RegA); @@ -1674,10 +1680,13 @@ bool TwoAddressInstructionPass::runOnMachineFunction(MachineFunction &Func) { SrcRegMap.clear(); DstRegMap.clear(); Processed.clear(); + SunkInstrs.clear(); for (MachineBasicBlock::iterator mi = MBB->begin(), me = MBB->end(); mi != me; ) { MachineBasicBlock::iterator nmi = std::next(mi); - if (mi->isDebugValue()) { + // Don't revisit an instruction previously converted by target. It may + // contain undef register operands (%noreg), which are not handled. + if (mi->isDebugValue() || SunkInstrs.count(&*mi)) { mi = nmi; continue; } |