[SystemZ] Require D12 for i128 accesses in isLegalAddressingMode() (#79221)

Machines with vector support handle i128 in vector registers and
therefore only have the small displacement available for memory
accesses. Update isLegalAddressingMode() to reflect this.

(cherry picked from commit 84dcf3d)

Author: JonPsson1

llvm/lib/Target/SystemZ/SystemZISelLowering.cpp

@@ -1067,7 +1067,8 @@ bool SystemZTargetLowering::isLegalAddressingMode(const DataLayout &DL,
   if (!isInt<20>(AM.BaseOffs))
     return false;
 
-  bool RequireD12 = Subtarget.hasVector() && Ty->isVectorTy();
+  bool RequireD12 =
+      Subtarget.hasVector() && (Ty->isVectorTy() || Ty->isIntegerTy(128));
   AddressingMode SupportedAM(!RequireD12, true);
   if (I != nullptr)
     SupportedAM = supportedAddressingMode(I, Subtarget.hasVector());

llvm/test/CodeGen/SystemZ/loop-01.ll

@@ -312,3 +312,26 @@ for.inc.i:                                        ; preds = %for.body.i63
   %indvars.iv.next156.i.3 = add nsw i64 %indvars.iv155.i, 4
   br label %for.body.i63
 }
+
+; Test that offsets are in range for i128 memory accesses.
+define void @fun10() {
+; CHECK-Z13-LABEL: fun10:
+; CHECK-Z13: # =>This Inner Loop Header: Depth=1
+; CHECK-Z13-NOT: lay
+entry:
+  %A1 = alloca [3 x [7 x [10 x i128]]], align 8
+  br label %for.body
+
+for.body:                        ; preds = %for.body, %entry
+  %IV = phi i64 [ 0, %entry ], [ %IV.next, %for.body ]
+  %Addr1 = getelementptr inbounds [3 x [7 x [10 x i128]]], ptr %A1, i64 0, i64 %IV, i64 6, i64 6
+  store i128 17174966165894859678, ptr %Addr1, align 8
+  %Addr2 = getelementptr inbounds [3 x [7 x [10 x i128]]], ptr %A1, i64 0, i64 %IV, i64 6, i64 8
+  store i128 17174966165894859678, ptr %Addr2, align 8
+  %IV.next = add nuw nsw i64 %IV, 1
+  %exitcond.not.i.i = icmp eq i64 %IV.next, 3
+  br i1 %exitcond.not.i.i, label %exit, label %for.body
+
+exit:                        ; preds = %for.body
+  unreachable
+}