diff --git a/cranelift/codegen/src/isa/s390x/lower.isle b/cranelift/codegen/src/isa/s390x/lower.isle
index e40d1203be..ed725d1dc3 100644
--- a/cranelift/codegen/src/isa/s390x/lower.isle
+++ b/cranelift/codegen/src/isa/s390x/lower.isle
@@ -239,9 +239,19 @@
 ;;;; Rules for `umax` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 ;; Unsigned maximum of two scalar integers - expand to icmp + select.
-(rule 1 (lower (has_type (ty_int ty) (umax x y)))
-      (let ((cond ProducesBool (icmp_val $false (IntCC.UnsignedLessThan) x y)))
-        (select_bool_reg ty cond y x)))
+(rule 2 (lower (has_type (fits_in_64 ty) (umax x y)))
+      (let ((x_ext Reg (put_in_reg_zext32 x))
+            (y_ext Reg (put_in_reg_zext32 y))
+            (cond ProducesBool (bool (icmpu_reg (ty_ext32 ty) x_ext y_ext)
+                                     (intcc_as_cond (IntCC.UnsignedLessThan)))))
+        (select_bool_reg ty cond y_ext x_ext)))
+
+;; Unsigned maximum of two 128-bit integers - expand to icmp + select.
+(rule 1 (lower (has_type $I128 (umax x y)))
+      (let ((x_reg Reg (put_in_reg x))
+            (y_reg Reg (put_in_reg y))
+            (cond ProducesBool (vec_int128_ucmphi y_reg x_reg)))
+        (select_bool_reg $I128 cond y_reg x_reg)))
 
 ;; Unsigned maximum of two vector registers.
 (rule 0 (lower (has_type (ty_vec128 ty) (umax x y)))
@@ -251,9 +261,19 @@
 ;;;; Rules for `umin` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 ;; Unsigned minimum of two scalar integers - expand to icmp + select.
-(rule 1 (lower (has_type (ty_int ty) (umin x y)))
-      (let ((cond ProducesBool (icmp_val $false (IntCC.UnsignedGreaterThan) x y)))
-        (select_bool_reg ty cond y x)))
+(rule 2 (lower (has_type (fits_in_64 ty) (umin x y)))
+      (let ((x_ext Reg (put_in_reg_zext32 x))
+            (y_ext Reg (put_in_reg_zext32 y))
+            (cond ProducesBool (bool (icmpu_reg (ty_ext32 ty) x_ext y_ext)
+                                     (intcc_as_cond (IntCC.UnsignedGreaterThan)))))
+        (select_bool_reg ty cond y_ext x_ext)))
+
+;; Unsigned maximum of two 128-bit integers - expand to icmp + select.
+(rule 1 (lower (has_type $I128 (umin x y)))
+      (let ((x_reg Reg (put_in_reg x))
+            (y_reg Reg (put_in_reg y))
+            (cond ProducesBool (vec_int128_ucmphi x_reg y_reg)))
+        (select_bool_reg $I128 cond y_reg x_reg)))
 
 ;; Unsigned minimum of two vector registers.
 (rule 0 (lower (has_type (ty_vec128 ty) (umin x y)))
@@ -263,9 +283,19 @@
 ;;;; Rules for `smax` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 ;; Signed maximum of two scalar integers - expand to icmp + select.
-(rule 1 (lower (has_type (ty_int ty) (smax x y)))
-      (let ((cond ProducesBool (icmp_val $false (IntCC.SignedLessThan) x y)))
-        (select_bool_reg ty cond y x)))
+(rule 2 (lower (has_type (fits_in_64 ty) (smax x y)))
+      (let ((x_ext Reg (put_in_reg_sext32 x))
+            (y_ext Reg (put_in_reg_sext32 y))
+            (cond ProducesBool (bool (icmps_reg (ty_ext32 ty) x_ext y_ext)
+                                     (intcc_as_cond (IntCC.SignedLessThan)))))
+        (select_bool_reg ty cond y_ext x_ext)))
+
+;; Signed maximum of two 128-bit integers - expand to icmp + select.
+(rule 1 (lower (has_type $I128 (smax x y)))
+      (let ((x_reg Reg (put_in_reg x))
+            (y_reg Reg (put_in_reg y))
+            (cond ProducesBool (vec_int128_scmphi y_reg x_reg)))
+        (select_bool_reg $I128 cond y_reg x_reg)))
 
 ;; Signed maximum of two vector registers.
 (rule (lower (has_type (ty_vec128 ty) (smax x y)))
@@ -275,9 +305,19 @@
 ;;;; Rules for `smin` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 ;; Signed minimum of two scalar integers - expand to icmp + select.
-(rule 1 (lower (has_type (ty_int ty) (smin x y)))
-      (let ((cond ProducesBool (icmp_val $false (IntCC.SignedGreaterThan) x y)))
-        (select_bool_reg ty cond y x)))
+(rule 2 (lower (has_type (fits_in_64 ty) (smin x y)))
+      (let ((x_ext Reg (put_in_reg_sext32 x))
+            (y_ext Reg (put_in_reg_sext32 y))
+            (cond ProducesBool (bool (icmps_reg (ty_ext32 ty) x_ext y_ext)
+                                     (intcc_as_cond (IntCC.SignedGreaterThan)))))
+        (select_bool_reg ty cond y_ext x_ext)))
+
+;; Signed maximum of two 128-bit integers - expand to icmp + select.
+(rule 1 (lower (has_type $I128 (smin x y)))
+      (let ((x_reg Reg (put_in_reg x))
+            (y_reg Reg (put_in_reg y))
+            (cond ProducesBool (vec_int128_scmphi x_reg y_reg)))
+        (select_bool_reg $I128 cond y_reg x_reg)))
 
 ;; Signed minimum of two vector registers.
 (rule (lower (has_type (ty_vec128 ty) (smin x y)))
diff --git a/cranelift/filetests/filetests/isa/s390x/minmax.clif b/cranelift/filetests/filetests/isa/s390x/minmax.clif
index c818a74a5f..a944794823 100644
--- a/cranelift/filetests/filetests/isa/s390x/minmax.clif
+++ b/cranelift/filetests/filetests/isa/s390x/minmax.clif
@@ -72,17 +72,17 @@ block0(v0: i16, v1: i16):
 
 ; VCode:
 ; block0:
-;   llhr %r5, %r2
-;   llhr %r4, %r3
-;   clr %r5, %r4
+;   llhr %r2, %r2
+;   llhr %r3, %r3
+;   clr %r2, %r3
 ;   locrl %r2, %r3
 ;   br %r14
 ; 
 ; Disassembled:
 ; block0: ; offset 0x0
-;   llhr %r5, %r2
-;   llhr %r4, %r3
-;   clr %r5, %r4
+;   llhr %r2, %r2
+;   llhr %r3, %r3
+;   clr %r2, %r3
 ;   locrl %r2, %r3
 ;   br %r14
 
@@ -94,17 +94,17 @@ block0(v0: i8, v1: i8):
 
 ; VCode:
 ; block0:
-;   llcr %r5, %r2
-;   llcr %r4, %r3
-;   clr %r5, %r4
+;   llcr %r2, %r2
+;   llcr %r3, %r3
+;   clr %r2, %r3
 ;   locrl %r2, %r3
 ;   br %r14
 ; 
 ; Disassembled:
 ; block0: ; offset 0x0
-;   llcr %r5, %r2
-;   llcr %r4, %r3
-;   clr %r5, %r4
+;   llcr %r2, %r2
+;   llcr %r3, %r3
+;   clr %r2, %r3
 ;   locrl %r2, %r3
 ;   br %r14
 
@@ -179,17 +179,17 @@ block0(v0: i16, v1: i16):
 
 ; VCode:
 ; block0:
-;   llhr %r5, %r2
-;   llhr %r4, %r3
-;   clr %r5, %r4
+;   llhr %r2, %r2
+;   llhr %r3, %r3
+;   clr %r2, %r3
 ;   locrh %r2, %r3
 ;   br %r14
 ; 
 ; Disassembled:
 ; block0: ; offset 0x0
-;   llhr %r5, %r2
-;   llhr %r4, %r3
-;   clr %r5, %r4
+;   llhr %r2, %r2
+;   llhr %r3, %r3
+;   clr %r2, %r3
 ;   locrh %r2, %r3
 ;   br %r14
 
@@ -201,17 +201,17 @@ block0(v0: i8, v1: i8):
 
 ; VCode:
 ; block0:
-;   llcr %r5, %r2
-;   llcr %r4, %r3
-;   clr %r5, %r4
+;   llcr %r2, %r2
+;   llcr %r3, %r3
+;   clr %r2, %r3
 ;   locrh %r2, %r3
 ;   br %r14
 ; 
 ; Disassembled:
 ; block0: ; offset 0x0
-;   llcr %r5, %r2
-;   llcr %r4, %r3
-;   clr %r5, %r4
+;   llcr %r2, %r2
+;   llcr %r3, %r3
+;   clr %r2, %r3
 ;   locrh %r2, %r3
 ;   br %r14
 
@@ -286,17 +286,17 @@ block0(v0: i16, v1: i16):
 
 ; VCode:
 ; block0:
-;   lhr %r5, %r2
-;   lhr %r4, %r3
-;   cr %r5, %r4
+;   lhr %r2, %r2
+;   lhr %r3, %r3
+;   cr %r2, %r3
 ;   locrl %r2, %r3
 ;   br %r14
 ; 
 ; Disassembled:
 ; block0: ; offset 0x0
-;   lhr %r5, %r2
-;   lhr %r4, %r3
-;   cr %r5, %r4
+;   lhr %r2, %r2
+;   lhr %r3, %r3
+;   cr %r2, %r3
 ;   locrl %r2, %r3
 ;   br %r14
 
@@ -308,17 +308,17 @@ block0(v0: i8, v1: i8):
 
 ; VCode:
 ; block0:
-;   lbr %r5, %r2
-;   lbr %r4, %r3
-;   cr %r5, %r4
+;   lbr %r2, %r2
+;   lbr %r3, %r3
+;   cr %r2, %r3
 ;   locrl %r2, %r3
 ;   br %r14
 ; 
 ; Disassembled:
 ; block0: ; offset 0x0
-;   lbr %r5, %r2
-;   lbr %r4, %r3
-;   cr %r5, %r4
+;   lbr %r2, %r2
+;   lbr %r3, %r3
+;   cr %r2, %r3
 ;   locrl %r2, %r3
 ;   br %r14
 
@@ -393,17 +393,17 @@ block0(v0: i16, v1: i16):
 
 ; VCode:
 ; block0:
-;   lhr %r5, %r2
-;   lhr %r4, %r3
-;   cr %r5, %r4
+;   lhr %r2, %r2
+;   lhr %r3, %r3
+;   cr %r2, %r3
 ;   locrh %r2, %r3
 ;   br %r14
 ; 
 ; Disassembled:
 ; block0: ; offset 0x0
-;   lhr %r5, %r2
-;   lhr %r4, %r3
-;   cr %r5, %r4
+;   lhr %r2, %r2
+;   lhr %r3, %r3
+;   cr %r2, %r3
 ;   locrh %r2, %r3
 ;   br %r14
 
@@ -415,17 +415,17 @@ block0(v0: i8, v1: i8):
 
 ; VCode:
 ; block0:
-;   lbr %r5, %r2
-;   lbr %r4, %r3
-;   cr %r5, %r4
+;   lbr %r2, %r2
+;   lbr %r3, %r3
+;   cr %r2, %r3
 ;   locrh %r2, %r3
 ;   br %r14
 ; 
 ; Disassembled:
 ; block0: ; offset 0x0
-;   lbr %r5, %r2
-;   lbr %r4, %r3
-;   cr %r5, %r4
+;   lbr %r2, %r2
+;   lbr %r3, %r3
+;   cr %r2, %r3
 ;   locrh %r2, %r3
 ;   br %r14