move isOnlyReachableByFallthrough out of MachineBasicBlock into AsmPrinter,
and add a sparc implementation that knows about delay slots. Patch by
Nathan Keynes!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96492 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/CodeGen/AsmPrinter.h b/include/llvm/CodeGen/AsmPrinter.h
index 28a1a3e..d4e8887 100644
--- a/include/llvm/CodeGen/AsmPrinter.h
+++ b/include/llvm/CodeGen/AsmPrinter.h
@@ -356,6 +356,11 @@
/// printOffset - This is just convenient handler for printing offsets.
void printOffset(int64_t Offset) const;
+ /// isBlockOnlyReachableByFallthough - Return true if the basic block has
+ /// exactly one predecessor and the control transfer mechanism between
+ /// the predecessor and this block is a fall-through.
+ virtual bool isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const;
+
private:
/// processDebugLoc - Processes the debug information of each machine
diff --git a/include/llvm/CodeGen/MachineBasicBlock.h b/include/llvm/CodeGen/MachineBasicBlock.h
index db82ba5..d92650b 100644
--- a/include/llvm/CodeGen/MachineBasicBlock.h
+++ b/include/llvm/CodeGen/MachineBasicBlock.h
@@ -285,11 +285,6 @@
/// it returns end()
iterator getFirstTerminator();
- /// isOnlyReachableViaFallthough - Return true if this basic block has
- /// exactly one predecessor and the control transfer mechanism between
- /// the predecessor and this block is a fall-through.
- bool isOnlyReachableByFallthrough() const;
-
void pop_front() { Insts.pop_front(); }
void pop_back() { Insts.pop_back(); }
void push_back(MachineInstr *MI) { Insts.push_back(MI); }
diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index fc08384..9f905db 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1717,7 +1717,7 @@
}
// Print the main label for the block.
- if (MBB->pred_empty() || MBB->isOnlyReachableByFallthrough()) {
+ if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
if (VerboseAsm) {
// NOTE: Want this comment at start of line.
O << MAI->getCommentString() << " BB#" << MBB->getNumber() << ':';
@@ -1764,6 +1764,39 @@
O << Offset;
}
+/// isBlockOnlyReachableByFallthough - Return true if the basic block has
+/// exactly one predecessor and the control transfer mechanism between
+/// the predecessor and this block is a fall-through.
+bool AsmPrinter::isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB)
+ const {
+ // If this is a landing pad, it isn't a fall through. If it has no preds,
+ // then nothing falls through to it.
+ if (MBB->isLandingPad() || MBB->pred_empty())
+ return false;
+
+ // If there isn't exactly one predecessor, it can't be a fall through.
+ MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
+ ++PI2;
+ if (PI2 != MBB->pred_end())
+ return false;
+
+ // The predecessor has to be immediately before this block.
+ const MachineBasicBlock *Pred = *PI;
+
+ if (!Pred->isLayoutSuccessor(MBB))
+ return false;
+
+ // If the block is completely empty, then it definitely does fall through.
+ if (Pred->empty())
+ return true;
+
+ // Otherwise, check the last instruction.
+ const MachineInstr &LastInst = Pred->back();
+ return !LastInst.getDesc().isBarrier();
+}
+
+
+
GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
if (!S->usesMetadata())
return 0;
diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index 655a0bf..64134ce 100644
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -143,36 +143,6 @@
return I;
}
-/// isOnlyReachableViaFallthough - Return true if this basic block has
-/// exactly one predecessor and the control transfer mechanism between
-/// the predecessor and this block is a fall-through.
-bool MachineBasicBlock::isOnlyReachableByFallthrough() const {
- // If this is a landing pad, it isn't a fall through. If it has no preds,
- // then nothing falls through to it.
- if (isLandingPad() || pred_empty())
- return false;
-
- // If there isn't exactly one predecessor, it can't be a fall through.
- const_pred_iterator PI = pred_begin(), PI2 = PI;
- ++PI2;
- if (PI2 != pred_end())
- return false;
-
- // The predecessor has to be immediately before this block.
- const MachineBasicBlock *Pred = *PI;
-
- if (!Pred->isLayoutSuccessor(this))
- return false;
-
- // If the block is completely empty, then it definitely does fall through.
- if (Pred->empty())
- return true;
-
- // Otherwise, check the last instruction.
- const MachineInstr &LastInst = Pred->back();
- return !LastInst.getDesc().isBarrier();
-}
-
void MachineBasicBlock::dump() const {
print(dbgs());
}
diff --git a/lib/Target/Sparc/AsmPrinter/SparcAsmPrinter.cpp b/lib/Target/Sparc/AsmPrinter/SparcAsmPrinter.cpp
index 9a2ce6b..ecb8b00 100644
--- a/lib/Target/Sparc/AsmPrinter/SparcAsmPrinter.cpp
+++ b/lib/Target/Sparc/AsmPrinter/SparcAsmPrinter.cpp
@@ -56,6 +56,9 @@
unsigned AsmVariant, const char *ExtraCode);
bool printGetPCX(const MachineInstr *MI, unsigned OpNo);
+
+ virtual bool isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB)
+ const;
};
} // end of anonymous namespace
@@ -197,6 +200,38 @@
return false;
}
+/// isBlockOnlyReachableByFallthough - Return true if the basic block has
+/// exactly one predecessor and the control transfer mechanism between
+/// the predecessor and this block is a fall-through.
+/// Override AsmPrinter implementation to handle delay slots
+bool SparcAsmPrinter::isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB)
+ const {
+ // If this is a landing pad, it isn't a fall through. If it has no preds,
+ // then nothing falls through to it.
+ if (MBB->isLandingPad() || MBB->pred_empty())
+ return false;
+
+ // If there isn't exactly one predecessor, it can't be a fall through.
+ MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
+ ++PI2;
+ if (PI2 != MBB->pred_end())
+ return false;
+
+ // The predecessor has to be immediately before this block.
+ const MachineBasicBlock *Pred = *PI;
+
+ if (!Pred->isLayoutSuccessor(MBB))
+ return false;
+
+ // Check if the last terminator is an unconditional branch
+ MachineBasicBlock::const_iterator I = Pred->end();
+ while( I != Pred->begin() && !(--I)->getDesc().isTerminator() )
+ ; /* Noop */
+ return I == Pred->end() || !I->getDesc().isBarrier();
+}
+
+
+
// Force static initialization.
extern "C" void LLVMInitializeSparcAsmPrinter() {
RegisterAsmPrinter<SparcAsmPrinter> X(TheSparcTarget);
diff --git a/utils/TableGen/DAGISelEmitter.cpp b/utils/TableGen/DAGISelEmitter.cpp
index e0e2573..28ac762 100644
--- a/utils/TableGen/DAGISelEmitter.cpp
+++ b/utils/TableGen/DAGISelEmitter.cpp
@@ -1975,7 +1975,7 @@
// definitions. Emit the resultant instruction selector.
EmitInstructionSelector(OS);
-#if 0
+#if 1
MatcherNode *Matcher = 0;
// Walk the patterns backwards, building a matcher for each and adding it to
// the matcher for the whole target.