[InstCombine] Add more vscale icmp tests (NFC)

In particular cover cases where vscale_range entries are larger
than the vscale bitwidth.

Author: nikic

llvm/test/Transforms/InstCombine/icmp-vscale.ll

@@ -126,6 +126,79 @@ define i1 @vscale_ugt_min() vscale_range(5,10) {
   ret i1 %res
 }
 
+define i1 @vscale_uge_no_max() vscale_range(5) {
+; CHECK-LABEL: @vscale_uge_no_max(
+; CHECK-NEXT:    ret i1 true
+;
+  %vscale = call i8 @llvm.vscale.i8()
+  %res = icmp uge i8 %vscale, 5
+  ret i1 %res
+}
+
+define i1 @vscale_ugt_no_max() vscale_range(5) {
+; CHECK-LABEL: @vscale_ugt_no_max(
+; CHECK-NEXT:    ret i1 false
+;
+  %vscale = call i8 @llvm.vscale.i8()
+  %res = icmp ugt i8 %vscale, 5
+  ret i1 %res
+}
+
+define i1 @vscale_uge_max_overflow() vscale_range(5,256) {
+; CHECK-LABEL: @vscale_uge_max_overflow(
+; CHECK-NEXT:    [[VSCALE:%.*]] = call i8 @llvm.vscale.i8()
+; CHECK-NEXT:    [[RES:%.*]] = icmp ugt i8 [[VSCALE]], 4
+; CHECK-NEXT:    ret i1 [[RES]]
+;
+  %vscale = call i8 @llvm.vscale.i8()
+  %res = icmp uge i8 %vscale, 5
+  ret i1 %res
+}
+
+define i1 @vscale_ugt_max_overflow() vscale_range(5,256) {
+; CHECK-LABEL: @vscale_ugt_max_overflow(
+; CHECK-NEXT:    [[VSCALE:%.*]] = call i8 @llvm.vscale.i8()
+; CHECK-NEXT:    [[RES:%.*]] = icmp ugt i8 [[VSCALE]], 5
+; CHECK-NEXT:    ret i1 [[RES]]
+;
+  %vscale = call i8 @llvm.vscale.i8()
+  %res = icmp ugt i8 %vscale, 5
+  ret i1 %res
+}
+
+define i1 @vscale_eq_min_overflow() vscale_range(256,300) {
+; CHECK-LABEL: @vscale_eq_min_overflow(
+; CHECK-NEXT:    [[VSCALE:%.*]] = call i8 @llvm.vscale.i8()
+; CHECK-NEXT:    [[RES:%.*]] = icmp eq i8 [[VSCALE]], 42
+; CHECK-NEXT:    ret i1 [[RES]]
+;
+  %vscale = call i8 @llvm.vscale.i8()
+  %res = icmp eq i8 %vscale, 42
+  ret i1 %res
+}
+
+define i1 @vscale_ult_min_overflow() vscale_range(256,300) {
+; CHECK-LABEL: @vscale_ult_min_overflow(
+; CHECK-NEXT:    [[VSCALE:%.*]] = call i8 @llvm.vscale.i8()
+; CHECK-NEXT:    [[RES:%.*]] = icmp ult i8 [[VSCALE]], 42
+; CHECK-NEXT:    ret i1 [[RES]]
+;
+  %vscale = call i8 @llvm.vscale.i8()
+  %res = icmp ult i8 %vscale, 42
+  ret i1 %res
+}
+
+define i1 @vscale_ugt_min_overflow() vscale_range(256,300) {
+; CHECK-LABEL: @vscale_ugt_min_overflow(
+; CHECK-NEXT:    [[VSCALE:%.*]] = call i8 @llvm.vscale.i8()
+; CHECK-NEXT:    [[RES:%.*]] = icmp ult i8 [[VSCALE]], 42
+; CHECK-NEXT:    ret i1 [[RES]]
+;
+  %vscale = call i8 @llvm.vscale.i8()
+  %res = icmp ult i8 %vscale, 42
+  ret i1 %res
+}
+
 declare i8 @llvm.vscale.i8()
 declare i16 @llvm.vscale.i16()
 declare i32 @llvm.vscale.i32()