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authorEli Bendersky <eliben@chromium.org>2013-07-15 16:09:15 -0700
committerEli Bendersky <eliben@chromium.org>2013-07-15 16:09:15 -0700
commitc6cf05cb5108f356dde97c01ee4188b0671d4542 (patch)
tree436fdc2a55296d3c202e7ef11f31be3be53efb5f /lib/CodeGen/SelectionDAG/FastISel.cpp
parentc75199c649c739aade160289d93f257edc798cde (diff)
parent7dfcb84fc16b3bf6b2379713b53090757f0a45f9 (diff)
Merge commit '7dfcb84fc16b3bf6b2379713b53090757f0a45f9'
Conflicts: docs/LangRef.rst include/llvm/CodeGen/CallingConvLower.h include/llvm/IRReader/IRReader.h include/llvm/Target/TargetMachine.h lib/CodeGen/CallingConvLower.cpp lib/IRReader/IRReader.cpp lib/IRReader/LLVMBuild.txt lib/IRReader/Makefile lib/LLVMBuild.txt lib/Makefile lib/Support/MemoryBuffer.cpp lib/Support/Unix/PathV2.inc lib/Target/ARM/ARMBaseInstrInfo.cpp lib/Target/ARM/ARMISelLowering.cpp lib/Target/ARM/ARMInstrInfo.td lib/Target/ARM/ARMSubtarget.cpp lib/Target/ARM/ARMTargetMachine.cpp lib/Target/Mips/CMakeLists.txt lib/Target/Mips/MipsDelaySlotFiller.cpp lib/Target/Mips/MipsISelLowering.cpp lib/Target/Mips/MipsInstrInfo.td lib/Target/Mips/MipsSubtarget.cpp lib/Target/Mips/MipsSubtarget.h lib/Target/X86/X86FastISel.cpp lib/Target/X86/X86ISelDAGToDAG.cpp lib/Target/X86/X86ISelLowering.cpp lib/Target/X86/X86InstrControl.td lib/Target/X86/X86InstrFormats.td lib/Transforms/IPO/ExtractGV.cpp lib/Transforms/InstCombine/InstCombineCompares.cpp lib/Transforms/Utils/SimplifyLibCalls.cpp test/CodeGen/X86/fast-isel-divrem.ll test/MC/ARM/data-in-code.ll tools/Makefile tools/llvm-extract/llvm-extract.cpp tools/llvm-link/CMakeLists.txt tools/opt/CMakeLists.txt tools/opt/LLVMBuild.txt tools/opt/Makefile tools/opt/opt.cpp
Diffstat (limited to 'lib/CodeGen/SelectionDAG/FastISel.cpp')
-rw-r--r--lib/CodeGen/SelectionDAG/FastISel.cpp67
1 files changed, 67 insertions, 0 deletions
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index 04f5b32e04..288499ac6f 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -696,6 +696,13 @@ bool FastISel::SelectCall(const User *I) {
UpdateValueMap(Call, ResultReg);
return true;
}
+ case Intrinsic::expect: {
+ unsigned ResultReg = getRegForValue(Call->getArgOperand(0));
+ if (ResultReg == 0)
+ return false;
+ UpdateValueMap(Call, ResultReg);
+ return true;
+ }
}
// Usually, it does not make sense to initialize a value,
@@ -1176,6 +1183,8 @@ unsigned FastISel::FastEmit_ri_(MVT VT, unsigned Opcode,
IntegerType *ITy = IntegerType::get(FuncInfo.Fn->getContext(),
VT.getSizeInBits());
MaterialReg = getRegForValue(ConstantInt::get(ITy, Imm));
+ assert (MaterialReg != 0 && "Unable to materialize imm.");
+ if (MaterialReg == 0) return 0;
}
return FastEmit_rr(VT, VT, Opcode,
Op0, Op0IsKill,
@@ -1496,3 +1505,61 @@ bool FastISel::HandlePHINodesInSuccessorBlocks(const BasicBlock *LLVMBB) {
return true;
}
+
+bool FastISel::tryToFoldLoad(const LoadInst *LI, const Instruction *FoldInst) {
+ assert(LI->hasOneUse() &&
+ "tryToFoldLoad expected a LoadInst with a single use");
+ // We know that the load has a single use, but don't know what it is. If it
+ // isn't one of the folded instructions, then we can't succeed here. Handle
+ // this by scanning the single-use users of the load until we get to FoldInst.
+ unsigned MaxUsers = 6; // Don't scan down huge single-use chains of instrs.
+
+ const Instruction *TheUser = LI->use_back();
+ while (TheUser != FoldInst && // Scan up until we find FoldInst.
+ // Stay in the right block.
+ TheUser->getParent() == FoldInst->getParent() &&
+ --MaxUsers) { // Don't scan too far.
+ // If there are multiple or no uses of this instruction, then bail out.
+ if (!TheUser->hasOneUse())
+ return false;
+
+ TheUser = TheUser->use_back();
+ }
+
+ // If we didn't find the fold instruction, then we failed to collapse the
+ // sequence.
+ if (TheUser != FoldInst)
+ return false;
+
+ // Don't try to fold volatile loads. Target has to deal with alignment
+ // constraints.
+ if (LI->isVolatile())
+ return false;
+
+ // Figure out which vreg this is going into. If there is no assigned vreg yet
+ // then there actually was no reference to it. Perhaps the load is referenced
+ // by a dead instruction.
+ unsigned LoadReg = getRegForValue(LI);
+ if (LoadReg == 0)
+ return false;
+
+ // We can't fold if this vreg has no uses or more than one use. Multiple uses
+ // may mean that the instruction got lowered to multiple MIs, or the use of
+ // the loaded value ended up being multiple operands of the result.
+ if (!MRI.hasOneUse(LoadReg))
+ return false;
+
+ MachineRegisterInfo::reg_iterator RI = MRI.reg_begin(LoadReg);
+ MachineInstr *User = &*RI;
+
+ // Set the insertion point properly. Folding the load can cause generation of
+ // other random instructions (like sign extends) for addressing modes; make
+ // sure they get inserted in a logical place before the new instruction.
+ FuncInfo.InsertPt = User;
+ FuncInfo.MBB = User->getParent();
+
+ // Ask the target to try folding the load.
+ return tryToFoldLoadIntoMI(User, RI.getOperandNo(), LI);
+}
+
+