[llvm-commits] CVS: llvm/lib/Transforms/Utils/DemoteRegToStack.cpp
Chris Lattner
lattner at cs.uiuc.edu
Tue Sep 27 12:39:12 PDT 2005
Changes in directory llvm/lib/Transforms/Utils:
DemoteRegToStack.cpp updated: 1.13 -> 1.14
---
Log message:
allow demotion to volatile values, add support for invoke
---
Diffs of the changes: (+15 -12)
DemoteRegToStack.cpp | 27 +++++++++++++++------------
1 files changed, 15 insertions(+), 12 deletions(-)
Index: llvm/lib/Transforms/Utils/DemoteRegToStack.cpp
diff -u llvm/lib/Transforms/Utils/DemoteRegToStack.cpp:1.13 llvm/lib/Transforms/Utils/DemoteRegToStack.cpp:1.14
--- llvm/lib/Transforms/Utils/DemoteRegToStack.cpp:1.13 Thu Apr 21 18:45:34 2005
+++ llvm/lib/Transforms/Utils/DemoteRegToStack.cpp Tue Sep 27 14:39:00 2005
@@ -29,7 +29,7 @@
/// invalidating the SSA information for the value. It returns the pointer to
/// the alloca inserted to create a stack slot for I.
///
-AllocaInst* llvm::DemoteRegToStack(Instruction &I) {
+AllocaInst* llvm::DemoteRegToStack(Instruction &I, bool VolatileLoads) {
if (I.use_empty()) return 0; // nothing to do!
// Create a stack slot to hold the value.
@@ -57,7 +57,7 @@
Value *&V = Loads[PN->getIncomingBlock(i)];
if (V == 0) {
// Insert the load into the predecessor block
- V = new LoadInst(Slot, I.getName()+".reload",
+ V = new LoadInst(Slot, I.getName()+".reload", VolatileLoads,
PN->getIncomingBlock(i)->getTerminator());
}
PN->setIncomingValue(i, V);
@@ -65,7 +65,7 @@
} else {
// If this is a normal instruction, just insert a load.
- Value *V = new LoadInst(Slot, I.getName()+".reload", U);
+ Value *V = new LoadInst(Slot, I.getName()+".reload", VolatileLoads, U);
U->replaceUsesOfWith(&I, V);
}
}
@@ -74,18 +74,21 @@
// Insert stores of the computed value into the stack slot. We have to be
// careful is I is an invoke instruction though, because we can't insert the
// store AFTER the terminator instruction.
+ BasicBlock::iterator InsertPt;
if (!isa<TerminatorInst>(I)) {
- BasicBlock::iterator InsertPt = &I;
- for (++InsertPt; isa<PHINode>(InsertPt); ++InsertPt)
- /* empty */; // Don't insert before any PHI nodes.
- new StoreInst(&I, Slot, InsertPt);
+ InsertPt = &I;
} else {
- // FIXME: We cannot yet demote invoke instructions to the stack, because
- // doing so would require breaking critical edges. This should be fixed
- // eventually.
- assert(0 &&
- "Cannot demote the value computed by an invoke instruction yet!");
+ // We cannot demote invoke instructions to the stack if their normal edge
+ // is critical.
+ InvokeInst &II = cast<InvokeInst>(I);
+ assert(II.getNormalDest()->getSinglePredecessor() &&
+ "Cannot demote invoke with a critical successor!");
+ InsertPt = II.getNormalDest()->begin();
}
+ for (++InsertPt; isa<PHINode>(InsertPt); ++InsertPt)
+ /* empty */; // Don't insert before any PHI nodes.
+ new StoreInst(&I, Slot, InsertPt);
+
return Slot;
}
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