[llvm] [AMDGPU] Accept arbitrary sized sources in CalculateByteProvider (PR #70240)

[Matt Arsenault via llvm-commits]

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@@ -11233,15 +11259,68 @@ static bool hasNon16BitAccesses(uint64_t PermMask, SDValue &Op,
   return !addresses16Bits(Low16) || !addresses16Bits(Hi16);
 }
 
+static SDValue getDWordFromOffset(SelectionDAG &DAG, SDLoc SL, SDValue Src,
+                                  unsigned DWordOffset) {
+  SDValue Ret;
+
+  auto ValueSize = Src.getValueSizeInBits().getFixedValue();
+  // ByteProvider must be at least 8 bits
+  assert(!(ValueSize % 8));
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arsenm wrote:

.isKnownMultipleOf(8)

https://github.com/llvm/llvm-project/pull/70240