Changeset 1297:8e8552601ecd

Timestamp:

05/03/09 12:01:45 (3 years ago)

Author:

Frits van Bommel <fvbommel wxs.nl>

branch:

default

Message:

Stack promotion for _d_newarrayvT. Array literals, concatenations (a ~ b) and
such are eligible for stack-allocation now.

Files:

• gen/passes/GarbageCollect2Stack.cpp (modified) (6 diffs)

gen/passes/GarbageCollect2Stack.cpp

@@ -30 +30 @@
-#include "llvm/Support/IRBuilder.h"
-#include "llvm/Analysis/CaptureTracking.h"
+#include "llvm/Analysis/ValueTracking.h"
-#include "llvm/Analysis/LoopInfo.h"
-#include "llvm/Target/TargetData.h"
@@ -38 +39 @@
-using namespace llvm;
-
-
+
+
-STATISTIC(NumDeleted, "Number of GC calls deleted because the return value was unused");
-
@@ -48 +50 @@
-    struct FunctionInfo {
-        unsigned TypeInfoArgNr;
+        int ArrSizeArgNr;
-        bool SafeToDelete;
-        
-
-
-
-
-
-
+
+
+
-    };
-    
@@ -93 +93 @@
-bool GarbageCollect2Stack::doInitialization(Module &M) {
-    this->M = &M;
-
+
+
-}
-
@@ -101 +102 @@
-    DEBUG(DOUT << "Running -dgc2stack on function " << F.getName() << '\n');
-    
-const 
+
-    const LoopInfo &LI = getAnalysis<LoopInfo>();
-    
@@ -162 +163 @@
-            }
-            
+            Value* arrSize = 0;
+            if (info->ArrSizeArgNr != -1) {
+                arrSize = CS.getArgument(info->ArrSizeArgNr);
+                const IntegerType* SizeType =
+                    dyn_cast<IntegerType>(arrSize->getType());
+                if (!SizeType)
+                    continue;
+                unsigned bits = SizeType->getBitWidth();
+                if (bits > 32) {
+                    // The array size of an alloca must be an i32, so make sure
+                    // the conversion is safe.
+                    APInt Mask = APInt::getHighBitsSet(bits, bits - 32);
+                    APInt KnownZero(bits, 0), KnownOne(bits, 0);
+                    ComputeMaskedBits(arrSize, Mask, KnownZero, KnownOne, &TD);
+                    if ((KnownZero & Mask) != Mask)
+                        continue;
+                }
+                // Extract the element type from the array type.
+                const StructType* ArrTy = dyn_cast<StructType>(Ty);
+                assert(ArrTy && "Dynamic array type not a struct?");
+                assert(isa<IntegerType>(ArrTy->getElementType(0)));
+                const PointerType* PtrTy =
+                    cast<PointerType>(ArrTy->getElementType(1));
+                Ty = PtrTy->getElementType();
+            }
+            
-            // Let's alloca this!
-            Changed = true;
-
-
-
-
-
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
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+
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+
+
+
-            if (newVal->getType() != Inst->getType())
-
-
+
-            Inst->replaceAllUsesWith(newVal);
-            
+            // If this was an invoke instruction, update the control flow.
-            if (InvokeInst* Invoke = dyn_cast<InvokeInst>(Inst)) {
+                // Notify the exception landing pad block that we won't be
+                // going there anymore.
-                Invoke->getUnwindDest()->removePredecessor(Invoke->getParent());
-                // Create a branch to the "normal" destination.
-                BranchInst::Create(Invoke->getNormalDest(), Invoke->getParent());
-            }
+            
+            // Finally, remove the runtime call.
-            Inst->eraseFromParent();
-        }
-    }
+    
-    return Changed;
-}