[fast-isel] Fallback to SelectionDAG isel if we require strict alignment for

[oota-llvm.git] / lib / Target / ARM / ARMConstantIslandPass.cpp

diff --git a/lib/Target/ARM/ARMConstantIslandPass.cpp b/lib/Target/ARM/ARMConstantIslandPass.cpp
index 896955170a5e405a58b82ace8b8126361ed07164..dd05f0cf409a8fba0d3f9d691518406434a962fb 100644 (file)
--- a/lib/Target/ARM/ARMConstantIslandPass.cpp
+++ b/lib/Target/ARM/ARMConstantIslandPass.cpp
@@ -124,7 +124,12 @@ namespace {
       /// This number should be used to predict worst case padding when
       /// splitting the block.
       unsigned internalKnownBits() const {
-        return Unalign ? Unalign : KnownBits;
+        unsigned Bits = Unalign ? Unalign : KnownBits;
+        // If the block size isn't a multiple of the known bits, assume the
+        // worst case padding.
+        if (Size & ((1u << Bits) - 1))
+          Bits = CountTrailingZeros_32(Size);
+        return Bits;
       }
 
       /// Compute the offset immediately following this block.  If LogAlign is
@@ -410,7 +415,7 @@ bool ARMConstantIslands::runOnMachineFunction(MachineFunction &mf) {
 
   // ARM and Thumb2 functions need to be 4-byte aligned.
   if (!isThumb1)
-    MF->EnsureAlignment(2);  // 2 = log2(4)
+    MF->ensureAlignment(2);  // 2 = log2(4)
 
   // Perform the initial placement of the constant pool entries.  To start with,
   // we put them all at the end of the function.
@@ -511,7 +516,7 @@ ARMConstantIslands::doInitialPlacement(std::vector<MachineInstr*> &CPEMIs) {
 
   // The function needs to be as aligned as the basic blocks. The linker may
   // move functions around based on their alignment.
-  MF->EnsureAlignment(BB->getAlignment());
+  MF->ensureAlignment(BB->getAlignment());
 
   // Order the entries in BB by descending alignment.  That ensures correct
   // alignment of all entries as long as BB is sufficiently aligned.  Keep
@@ -810,7 +815,7 @@ void ARMConstantIslands::computeBlockSize(MachineBasicBlock *MBB) {
   // tBR_JTr contains a .align 2 directive.
   if (!MBB->empty() && MBB->back().getOpcode() == ARM::tBR_JTr) {
     BBI.PostAlign = 2;
-    MBB->getParent()->EnsureAlignment(2);
+    MBB->getParent()->ensureAlignment(2);
   }
 }
 
@@ -1301,9 +1306,10 @@ void ARMConstantIslands::createNewWater(unsigned CPUserIndex,
   // pool entries following this block; only the last one is in the water list.
   // Back past any possible branches (allow for a conditional and a maximally
   // long unconditional).
-  if (BaseInsertOffset >= BBInfo[UserMBB->getNumber()+1].Offset)
-    BaseInsertOffset = BBInfo[UserMBB->getNumber()+1].Offset -
-      (isThumb1 ? 6 : 8);
+  if (BaseInsertOffset + 8 >= UserBBI.postOffset()) {
+    BaseInsertOffset = UserBBI.postOffset() - UPad - 8;
+    DEBUG(dbgs() << format("Move inside block: %#x\n", BaseInsertOffset));
+  }
   unsigned EndInsertOffset = BaseInsertOffset + 4 + UPad +
     CPEMI->getOperand(2).getImm();
   MachineBasicBlock::iterator MI = UserMI;
@@ -1315,6 +1321,7 @@ void ARMConstantIslands::createNewWater(unsigned CPUserIndex,
        Offset < BaseInsertOffset;
        Offset += TII->GetInstSizeInBytes(MI),
        MI = llvm::next(MI)) {
+    assert(MI != UserMBB->end() && "Fell off end of block");
     if (CPUIndex < NumCPUsers && CPUsers[CPUIndex].MI == MI) {
       CPUser &U = CPUsers[CPUIndex];
       if (!isOffsetInRange(Offset, EndInsertOffset, U)) {
@@ -1381,10 +1388,9 @@ bool ARMConstantIslands::handleConstantPoolUser(unsigned CPUserIndex) {
     // If the original WaterList entry was "new water" on this iteration,
     // propagate that to the new island.  This is just keeping NewWaterList
     // updated to match the WaterList, which will be updated below.
-    if (NewWaterList.count(WaterBB)) {
-      NewWaterList.erase(WaterBB);
+    if (NewWaterList.erase(WaterBB))
       NewWaterList.insert(NewIsland);
-    }
+
     // The new CPE goes before the following block (NewMBB).
     NewMBB = llvm::next(MachineFunction::iterator(WaterBB));