diff --git a/llvm/lib/Target/RISCV/RISCV.td b/llvm/lib/Target/RISCV/RISCV.td
--- a/llvm/lib/Target/RISCV/RISCV.td
+++ b/llvm/lib/Target/RISCV/RISCV.td
@@ -62,6 +62,7 @@
 def HasStdExtZba : Predicate<"Subtarget->hasStdExtZba()">,
                              AssemblerPredicate<(all_of FeatureExtZba),
                              "'Zba' (Address calculation 'B' Instructions)">;
+def NotHasStdExtZba : Predicate<"!Subtarget->hasStdExtZba()">;
 
 def FeatureExtZbb
     : SubtargetFeature<"experimental-zbb", "HasStdExtZbb", "true",
@@ -131,8 +132,6 @@
 def HasStdExtZbbOrZbp
     : Predicate<"Subtarget->hasStdExtZbb() || Subtarget->hasStdExtZbp()">,
                 AssemblerPredicate<(any_of FeatureExtZbb, FeatureExtZbp)>;
-def NotHasStdExtZbbOrZbp
-    : Predicate<"!(Subtarget->hasStdExtZbb() || Subtarget->hasStdExtZbp())">;
 
 def FeatureExtZbproposedc
     : SubtargetFeature<"experimental-zbproposedc", "HasStdExtZbproposedc", "true",
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfo.td b/llvm/lib/Target/RISCV/RISCVInstrInfo.td
--- a/llvm/lib/Target/RISCV/RISCVInstrInfo.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfo.td
@@ -1158,7 +1158,7 @@
 
 /// RV64 patterns
 
-let Predicates = [IsRV64, NotHasStdExtZbbOrZbp] in
+let Predicates = [IsRV64, NotHasStdExtZba] in
 def : Pat<(and GPR:$rs1, 0xffffffff), (SRLI (SLLI GPR:$rs1, 32), 32)>;
 
 let Predicates = [IsRV64] in {
diff --git a/llvm/lib/Target/RISCV/RISCVInstrInfoB.td b/llvm/lib/Target/RISCV/RISCVInstrInfoB.td
--- a/llvm/lib/Target/RISCV/RISCVInstrInfoB.td
+++ b/llvm/lib/Target/RISCV/RISCVInstrInfoB.td
@@ -495,7 +495,7 @@
 def C_NEG : RVBInstC<0b01, "c.neg">, Sched<[]>;
 } // DecoderNamespace = "RVBC", Predicates = [HasStdExtZbproposedc, HasStdExtC]
 
-let DecoderNamespace = "RVBC", Predicates = [HasStdExtZbproposedc, HasStdExtZbbOrZbp, HasStdExtC, IsRV64] in
+let DecoderNamespace = "RVBC", Predicates = [HasStdExtZbproposedc, HasStdExtZba, HasStdExtC, IsRV64] in
 def C_ZEXTW : RVBInstC<0b10, "c.zext.w">, Sched<[]>;
 
 //===----------------------------------------------------------------------===//
@@ -508,9 +508,14 @@
 
 let Predicates = [HasStdExtZbb, IsRV64] in {
 def : InstAlias<"zext.h $rd, $rs", (PACKW GPR:$rd, GPR:$rs, X0)>;
-def : InstAlias<"zext.w $rd, $rs", (PACK GPR:$rd, GPR:$rs, X0)>;
 } // Predicates = [HasStdExtZbb, IsRV64]
 
+let Predicates = [HasStdExtZba, IsRV64] in {
+// NOTE: The 0.93 spec shows zext.w as an alias of pack/packw. It has been
+// changed to add.uw in a draft after 0.94.
+def : InstAlias<"zext.w $rd, $rs", (ADDUW GPR:$rd, GPR:$rs, X0)>;
+}
+
 let Predicates = [HasStdExtZbp] in {
 def : InstAlias<"rev.p $rd, $rs",  (GREVI GPR:$rd, GPR:$rs, 0b00001)>;
 def : InstAlias<"rev2.n $rd, $rs", (GREVI GPR:$rd, GPR:$rs, 0b00010)>;
@@ -626,8 +631,8 @@
                   (C_NEG GPRC:$rs1)>;
 } // Predicates = [HasStdExtZbproposedc, HasStdExtC]
 
-let Predicates = [HasStdExtZbproposedc, HasStdExtZbbOrZbp, HasStdExtC, IsRV64] in {
-def : CompressPat<(PACK GPRC:$rs1, GPRC:$rs1, X0),
+let Predicates = [HasStdExtZbproposedc, HasStdExtZba, HasStdExtC, IsRV64] in {
+def : CompressPat<(ADDUW GPRC:$rs1, GPRC:$rs1, X0),
                   (C_ZEXTW GPRC:$rs1)>;
 } // Predicates = [HasStdExtZbproposedc, HasStdExtC, IsRV64]
 
@@ -806,7 +811,6 @@
 def : Pat<(and GPR:$rs, 0x0000FFFF), (PACK GPR:$rs, X0)>;
 let Predicates = [HasStdExtZbbOrZbp, IsRV64] in {
 def : Pat<(and GPR:$rs, 0x000000000000FFFF), (PACKW GPR:$rs, X0)>;
-def : Pat<(and GPR:$rs, 0x00000000FFFFFFFF), (PACK GPR:$rs, X0)>;
 }
 
 let Predicates = [HasStdExtZbp, IsRV32] in {
@@ -858,6 +862,7 @@
           (SLLIUW GPR:$rs1, uimm5:$shamt)>;
 def : Pat<(add (and GPR:$rs1, (i64 0xFFFFFFFF)), GPR:$rs2),
           (ADDUW GPR:$rs1, GPR:$rs2)>;
+def : Pat<(and GPR:$rs, 0x00000000FFFFFFFF), (ADDUW GPR:$rs, X0)>;
 }
 
 let Predicates = [HasStdExtZbp, IsRV64] in {
diff --git a/llvm/test/CodeGen/RISCV/rv64Zba.ll b/llvm/test/CodeGen/RISCV/rv64Zba.ll
--- a/llvm/test/CodeGen/RISCV/rv64Zba.ll
+++ b/llvm/test/CodeGen/RISCV/rv64Zba.ll
@@ -109,3 +109,23 @@
   %5 = load i8, i8* %4
   ret i8 %5
 }
+
+define i64 @zextw_i64(i64 %a) nounwind {
+; RV64I-LABEL: zextw_i64:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    slli a0, a0, 32
+; RV64I-NEXT:    srli a0, a0, 32
+; RV64I-NEXT:    ret
+;
+; RV64IB-LABEL: zextw_i64:
+; RV64IB:       # %bb.0:
+; RV64IB-NEXT:    zext.w a0, a0
+; RV64IB-NEXT:    ret
+;
+; RV64IBA-LABEL: zextw_i64:
+; RV64IBA:       # %bb.0:
+; RV64IBA-NEXT:    zext.w a0, a0
+; RV64IBA-NEXT:    ret
+  %and = and i64 %a, 4294967295
+  ret i64 %and
+}
diff --git a/llvm/test/CodeGen/RISCV/rv64Zbbp.ll b/llvm/test/CodeGen/RISCV/rv64Zbbp.ll
--- a/llvm/test/CodeGen/RISCV/rv64Zbbp.ll
+++ b/llvm/test/CodeGen/RISCV/rv64Zbbp.ll
@@ -792,28 +792,3 @@
   %or = or i64 %shl, %and
   ret i64 %or
 }
-
-define i64 @zextw_i64(i64 %a) nounwind {
-; RV64I-LABEL: zextw_i64:
-; RV64I:       # %bb.0:
-; RV64I-NEXT:    slli a0, a0, 32
-; RV64I-NEXT:    srli a0, a0, 32
-; RV64I-NEXT:    ret
-;
-; RV64IB-LABEL: zextw_i64:
-; RV64IB:       # %bb.0:
-; RV64IB-NEXT:    zext.w a0, a0
-; RV64IB-NEXT:    ret
-;
-; RV64IBB-LABEL: zextw_i64:
-; RV64IBB:       # %bb.0:
-; RV64IBB-NEXT:    zext.w a0, a0
-; RV64IBB-NEXT:    ret
-;
-; RV64IBP-LABEL: zextw_i64:
-; RV64IBP:       # %bb.0:
-; RV64IBP-NEXT:    pack a0, a0, zero
-; RV64IBP-NEXT:    ret
-  %and = and i64 %a, 4294967295
-  ret i64 %and
-}
diff --git a/llvm/test/MC/RISCV/rv64b-aliases-valid.s b/llvm/test/MC/RISCV/rv64b-aliases-valid.s
--- a/llvm/test/MC/RISCV/rv64b-aliases-valid.s
+++ b/llvm/test/MC/RISCV/rv64b-aliases-valid.s
@@ -23,7 +23,7 @@
 # CHECK-S-OBJ: zext.h t0, t1
 zext.h x5, x6
 
-# CHECK-S-OBJ-NOALIAS: pack t0, t1, zero
+# CHECK-S-OBJ-NOALIAS: add.uw t0, t1, zero
 # CHECK-S-OBJ: zext.w t0, t1
 zext.w x5, x6