Implement two virtual functions in SPUTargetLowering.

Before the implementation of isLegalAddressingMode, some rare cases
of code were miscompiled if optimized with the LoopStrengthReduce pass.
It is unclear (to me) if LSR is "allowed" to produce wrong code with a
bad TargetLowering, or if the bug is elsewhere and this patch just
hides it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115919 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/CellSPU/SPUISelLowering.cpp b/lib/Target/CellSPU/SPUISelLowering.cpp
index 0e63750fd89ccf0c8006f07272d10512a1ad5562..38b9f4e5233b5e258023f31e397659e3a8109757 100644 (file)
--- a/lib/Target/CellSPU/SPUISelLowering.cpp
+++ b/lib/Target/CellSPU/SPUISelLowering.cpp
@@ -3088,3 +3088,29 @@ SPUTargetLowering::isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const {
   // The SPU target isn't yet aware of offsets.
   return false;
 }
+
+// can we compare to Imm without writing it into a register?
+bool SPUTargetLowering::isLegalICmpImmediate(int64_t Imm) const {
+  //ceqi, cgti, etc. all take s10 operand
+  return isInt<10>(Imm);
+}
+
+bool 
+SPUTargetLowering::isLegalAddressingMode(const AddrMode &AM, 
+                                         const Type * ) const{
+
+  // A-form: 18bit absolute address. 
+  if (AM.BaseGV && !AM.HasBaseReg && AM.Scale == 0 && AM.BaseOffs == 0)
+    return true;
+ 
+  // D-form: reg + 14bit offset
+  if (AM.BaseGV ==0 && AM.HasBaseReg && AM.Scale == 0 && isInt<14>(AM.BaseOffs))
+    return true;
+
+  // X-form: reg+reg
+  if (AM.BaseGV == 0 && AM.HasBaseReg && AM.Scale == 1 && AM.BaseOffs ==0)
+    return true;
+
+  return false;
+}
+

diff --git a/lib/Target/CellSPU/SPUISelLowering.h b/lib/Target/CellSPU/SPUISelLowering.h
index 6d3c90b7512ce0d223708c543da7b5fbcdf099a8..23726435b8326d629be22ad805354951b0b26abc 100644 (file)
--- a/lib/Target/CellSPU/SPUISelLowering.h
+++ b/lib/Target/CellSPU/SPUISelLowering.h
@@ -170,6 +170,11 @@ namespace llvm {
                   const SmallVectorImpl<ISD::OutputArg> &Outs,
                   const SmallVectorImpl<SDValue> &OutVals,
                   DebugLoc dl, SelectionDAG &DAG) const;
+
+    virtual bool isLegalICmpImmediate(int64_t Imm) const;
+
+    virtual bool isLegalAddressingMode(const AddrMode &AM, 
+                                       const Type *Ty) const;
   };
 }