diff --git a/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp b/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp
--- a/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp
+++ b/llvm/lib/Target/AArch64/GISel/AArch64LegalizerInfo.cpp
@@ -529,6 +529,7 @@
   getActionDefinitionsBuilder(G_SEXT_INREG)
       .legalFor({s32, s64})
       .legalFor(PackedVectorAllTypeList)
+      .maxScalar(0, s64)
       .lower();
 
   // FP conversions
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/legalize-saddsat.mir b/llvm/test/CodeGen/AArch64/GlobalISel/legalize-saddsat.mir
--- a/llvm/test/CodeGen/AArch64/GlobalISel/legalize-saddsat.mir
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/legalize-saddsat.mir
@@ -238,16 +238,11 @@
     ; CHECK-NEXT: [[UV8:%[0-9]+]]:_(s8), [[UV9:%[0-9]+]]:_(s8), [[UV10:%[0-9]+]]:_(s8), [[UV11:%[0-9]+]]:_(s8) = G_UNMERGE_VALUES [[DEF1]](s32)
     ; CHECK-NEXT: [[MV:%[0-9]+]]:_(s32) = G_MERGE_VALUES [[UV4]](s8), [[UV5]](s8), [[UV6]](s8), [[DEF]](s8)
     ; CHECK-NEXT: [[MV1:%[0-9]+]]:_(s32) = G_MERGE_VALUES [[UV8]](s8), [[UV9]](s8), [[UV10]](s8), [[UV8]](s8)
-    ; CHECK-NEXT: [[C2:%[0-9]+]]:_(s64) = G_CONSTANT i64 40
     ; CHECK-NEXT: [[MV2:%[0-9]+]]:_(s64) = G_MERGE_VALUES [[MV]](s32), [[MV1]](s32)
-    ; CHECK-NEXT: [[SHL:%[0-9]+]]:_(s64) = G_SHL [[MV2]], [[C2]](s64)
-    ; CHECK-NEXT: [[C3:%[0-9]+]]:_(s64) = G_CONSTANT i64 24
-    ; CHECK-NEXT: [[LSHR:%[0-9]+]]:_(s64) = G_LSHR [[UADDO]], [[C3]](s64)
-    ; CHECK-NEXT: [[OR:%[0-9]+]]:_(s64) = G_OR [[SHL]], [[LSHR]]
-    ; CHECK-NEXT: [[ASHR:%[0-9]+]]:_(s64) = G_ASHR [[OR]], [[C2]](s64)
-    ; CHECK-NEXT: [[C4:%[0-9]+]]:_(s64) = G_CONSTANT i64 23
-    ; CHECK-NEXT: [[ASHR1:%[0-9]+]]:_(s64) = G_ASHR [[ASHR]], [[C4]](s64)
-    ; CHECK-NEXT: [[UADDO2:%[0-9]+]]:_(s64), [[UADDO3:%[0-9]+]]:_(s32) = G_UADDO [[ASHR1]], [[C]]
+    ; CHECK-NEXT: [[SEXT_INREG3:%[0-9]+]]:_(s64) = G_SEXT_INREG [[MV2]], 24
+    ; CHECK-NEXT: [[C2:%[0-9]+]]:_(s64) = G_CONSTANT i64 23
+    ; CHECK-NEXT: [[ASHR:%[0-9]+]]:_(s64) = G_ASHR [[SEXT_INREG3]], [[C2]](s64)
+    ; CHECK-NEXT: [[UADDO2:%[0-9]+]]:_(s64), [[UADDO3:%[0-9]+]]:_(s32) = G_UADDO [[ASHR]], [[C]]
     ; CHECK-NEXT: [[AND1:%[0-9]+]]:_(s32) = G_AND [[ICMP]], [[C1]]
     ; CHECK-NEXT: [[SELECT:%[0-9]+]]:_(s64) = G_SELECT [[AND1]](s32), [[UADDO2]], [[UADDO]]
     ; CHECK-NEXT: $x0 = COPY [[SELECT]](s64)
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/legalize-ssubsat.mir b/llvm/test/CodeGen/AArch64/GlobalISel/legalize-ssubsat.mir
--- a/llvm/test/CodeGen/AArch64/GlobalISel/legalize-ssubsat.mir
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/legalize-ssubsat.mir
@@ -238,16 +238,11 @@
     ; CHECK-NEXT: [[UV8:%[0-9]+]]:_(s8), [[UV9:%[0-9]+]]:_(s8), [[UV10:%[0-9]+]]:_(s8), [[UV11:%[0-9]+]]:_(s8) = G_UNMERGE_VALUES [[DEF1]](s32)
     ; CHECK-NEXT: [[MV:%[0-9]+]]:_(s32) = G_MERGE_VALUES [[UV4]](s8), [[UV5]](s8), [[UV6]](s8), [[DEF]](s8)
     ; CHECK-NEXT: [[MV1:%[0-9]+]]:_(s32) = G_MERGE_VALUES [[UV8]](s8), [[UV9]](s8), [[UV10]](s8), [[UV8]](s8)
-    ; CHECK-NEXT: [[C2:%[0-9]+]]:_(s64) = G_CONSTANT i64 40
     ; CHECK-NEXT: [[MV2:%[0-9]+]]:_(s64) = G_MERGE_VALUES [[MV]](s32), [[MV1]](s32)
-    ; CHECK-NEXT: [[SHL:%[0-9]+]]:_(s64) = G_SHL [[MV2]], [[C2]](s64)
-    ; CHECK-NEXT: [[C3:%[0-9]+]]:_(s64) = G_CONSTANT i64 24
-    ; CHECK-NEXT: [[LSHR:%[0-9]+]]:_(s64) = G_LSHR [[USUBO]], [[C3]](s64)
-    ; CHECK-NEXT: [[OR:%[0-9]+]]:_(s64) = G_OR [[SHL]], [[LSHR]]
-    ; CHECK-NEXT: [[ASHR:%[0-9]+]]:_(s64) = G_ASHR [[OR]], [[C2]](s64)
-    ; CHECK-NEXT: [[C4:%[0-9]+]]:_(s64) = G_CONSTANT i64 23
-    ; CHECK-NEXT: [[ASHR1:%[0-9]+]]:_(s64) = G_ASHR [[ASHR]], [[C4]](s64)
-    ; CHECK-NEXT: [[UADDO:%[0-9]+]]:_(s64), [[UADDO1:%[0-9]+]]:_(s32) = G_UADDO [[ASHR1]], [[C]]
+    ; CHECK-NEXT: [[SEXT_INREG3:%[0-9]+]]:_(s64) = G_SEXT_INREG [[MV2]], 24
+    ; CHECK-NEXT: [[C2:%[0-9]+]]:_(s64) = G_CONSTANT i64 23
+    ; CHECK-NEXT: [[ASHR:%[0-9]+]]:_(s64) = G_ASHR [[SEXT_INREG3]], [[C2]](s64)
+    ; CHECK-NEXT: [[UADDO:%[0-9]+]]:_(s64), [[UADDO1:%[0-9]+]]:_(s32) = G_UADDO [[ASHR]], [[C]]
     ; CHECK-NEXT: [[AND1:%[0-9]+]]:_(s32) = G_AND [[ICMP]], [[C1]]
     ; CHECK-NEXT: [[SELECT:%[0-9]+]]:_(s64) = G_SELECT [[AND1]](s32), [[UADDO]], [[USUBO]]
     ; CHECK-NEXT: $x0 = COPY [[SELECT]](s64)