1 files changed, 30 insertions, 4 deletions
diff --git a/llvm/lib/Target/R600/SIISelLowering.cpp b/llvm/lib/Target/R600/SIISelLowering.cpp
index ae405aca4e1..af38c94928a 100644
--- a/llvm/lib/Target/R600/SIISelLowering.cpp
+++ b/llvm/lib/Target/R600/SIISelLowering.cpp
@@ -1342,6 +1342,35 @@ SDValue SITargetLowering::performUCharToFloatCombine(SDNode *N,
   return SDValue();
 }
 
+/// \brief Return true if the given offset Size in bytes can be folded into
+/// the immediate offsets of a memory instruction for the given address space.
+static bool canFoldOffset(unsigned OffsetSize, unsigned AS,
+                          const AMDGPUSubtarget &STI) {
+  switch (AS) {
+  case AMDGPUAS::GLOBAL_ADDRESS: {
+    // MUBUF instructions a 12-bit offset in bytes.
+    return isUInt<12>(OffsetSize);
+  }
+  case AMDGPUAS::CONSTANT_ADDRESS: {
+    // SMRD instructions have an 8-bit offset in dwords on SI and
+    // a 20-bit offset in bytes on VI.
+    if (STI.getGeneration() >= AMDGPUSubtarget::VOLCANIC_ISLANDS)
+      return isUInt<20>(OffsetSize);
+    else
+      return (OffsetSize % 4 == 0) && isUInt<8>(OffsetSize / 4);
+  }
+  case AMDGPUAS::LOCAL_ADDRESS:
+  case AMDGPUAS::REGION_ADDRESS: {
+    // The single offset versions have a 16-bit offset in bytes.
+    return isUInt<16>(OffsetSize);
+  }
+  case AMDGPUAS::PRIVATE_ADDRESS:
+  // Indirect register addressing does not use any offsets.
+  default:
+    return 0;
+  }
+}
+
 // (shl (add x, c1), c2) -> add (shl x, c2), (shl c1, c2)
 
 // This is a variant of
@@ -1373,13 +1402,10 @@ SDValue SITargetLowering::performSHLPtrCombine(SDNode *N,
   if (!CAdd)
     return SDValue();
 
-  const SIInstrInfo *TII =
-      static_cast<const SIInstrInfo *>(Subtarget->getInstrInfo());
-
   // If the resulting offset is too large, we can't fold it into the addressing
   // mode offset.
   APInt Offset = CAdd->getAPIntValue() << CN1->getAPIntValue();
-  if (!TII->canFoldOffset(Offset.getZExtValue(), AddrSpace))
+  if (!canFoldOffset(Offset.getZExtValue(), AddrSpace, *Subtarget))
     return SDValue();
 
   SelectionDAG &DAG = DCI.DAG;