Index: llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
===================================================================
--- llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -4877,8 +4877,7 @@
   return nullptr;
 }
 
-static Instruction *foldICmpWithTrunc(ICmpInst &ICmp,
-                                      InstCombiner::BuilderTy &Builder) {
+Instruction *InstCombinerImpl::foldICmpWithTrunc(ICmpInst &ICmp) {
   ICmpInst::Predicate Pred = ICmp.getPredicate();
   Value *Op0 = ICmp.getOperand(0), *Op1 = ICmp.getOperand(1);
 
@@ -4916,6 +4915,18 @@
     return new ICmpInst(ICmpInst::ICMP_EQ, And, MaskC);
   }
 
+  if (auto *II = dyn_cast<IntrinsicInst>(X)) {
+    if (II->getIntrinsicID() == Intrinsic::ctpop ||
+        II->getIntrinsicID() == Intrinsic::cttz ||
+        II->getIntrinsicID() == Intrinsic::ctlz) {
+      // Make sure the dest bits is enough to save the intrinsic output's range
+      if (llvm::Log2_32_Ceil(SrcBits) < Op0->getType()->getScalarSizeInBits())
+        if (Instruction *I =
+                foldICmpIntrinsicWithConstant(ICmp, II, C->zext(SrcBits)))
+          return I;
+    }
+  }
+
   return nullptr;
 }
 
@@ -5073,7 +5084,7 @@
       return new ICmpInst(ICmp.getPredicate(), Op0Src, NewOp1);
   }
 
-  if (Instruction *R = foldICmpWithTrunc(ICmp, Builder))
+  if (Instruction *R = foldICmpWithTrunc(ICmp))
     return R;
 
   return foldICmpWithZextOrSext(ICmp);
Index: llvm/lib/Transforms/InstCombine/InstCombineInternal.h
===================================================================
--- llvm/lib/Transforms/InstCombine/InstCombineInternal.h
+++ llvm/lib/Transforms/InstCombine/InstCombineInternal.h
@@ -624,6 +624,7 @@
   Instruction *foldICmpEqIntrinsicWithConstant(ICmpInst &ICI, IntrinsicInst *II,
                                                const APInt &C);
   Instruction *foldICmpBitCast(ICmpInst &Cmp);
+  Instruction *foldICmpWithTrunc(ICmpInst &Cmp);
 
   // Helpers of visitSelectInst().
   Instruction *foldSelectOfBools(SelectInst &SI);
Index: llvm/test/Transforms/InstCombine/cmp-intrinsic.ll
===================================================================
--- llvm/test/Transforms/InstCombine/cmp-intrinsic.ll
+++ llvm/test/Transforms/InstCombine/cmp-intrinsic.ll
@@ -116,7 +116,7 @@
 
 define i1 @ctlz_eq_other_i32_multiuse(i32 %x, ptr %p) {
 ; CHECK-LABEL: @ctlz_eq_other_i32_multiuse(
-; CHECK-NEXT:    [[LZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[X:%.*]], i1 false), [[RNG0:!range !.*]]
+; CHECK-NEXT:    [[LZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[X:%.*]], i1 false), !range [[RNG0:![0-9]+]]
 ; CHECK-NEXT:    store i32 [[LZ]], ptr [[P:%.*]], align 4
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[LZ]], 24
 ; CHECK-NEXT:    ret i1 [[CMP]]
@@ -169,7 +169,7 @@
 
 define i1 @ctlz_ugt_other_multiuse_i32(i32 %x, ptr %p) {
 ; CHECK-LABEL: @ctlz_ugt_other_multiuse_i32(
-; CHECK-NEXT:    [[LZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[X:%.*]], i1 false), [[RNG0]]
+; CHECK-NEXT:    [[LZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[X:%.*]], i1 false), !range [[RNG0]]
 ; CHECK-NEXT:    store i32 [[LZ]], ptr [[P:%.*]], align 4
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[X]], 32768
 ; CHECK-NEXT:    ret i1 [[CMP]]
@@ -329,7 +329,7 @@
 
 define i1 @cttz_eq_other_i33_multiuse(i33 %x, ptr %p) {
 ; CHECK-LABEL: @cttz_eq_other_i33_multiuse(
-; CHECK-NEXT:    [[TZ:%.*]] = tail call i33 @llvm.cttz.i33(i33 [[X:%.*]], i1 false), [[RNG1:!range !.*]]
+; CHECK-NEXT:    [[TZ:%.*]] = tail call i33 @llvm.cttz.i33(i33 [[X:%.*]], i1 false), !range [[RNG1:![0-9]+]]
 ; CHECK-NEXT:    store i33 [[TZ]], ptr [[P:%.*]], align 4
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i33 [[TZ]], 4
 ; CHECK-NEXT:    ret i1 [[CMP]]
@@ -375,7 +375,7 @@
 
 define i1 @cttz_ugt_other_multiuse_i33(i33 %x, ptr %p) {
 ; CHECK-LABEL: @cttz_ugt_other_multiuse_i33(
-; CHECK-NEXT:    [[TZ:%.*]] = tail call i33 @llvm.cttz.i33(i33 [[X:%.*]], i1 false), [[RNG1]]
+; CHECK-NEXT:    [[TZ:%.*]] = tail call i33 @llvm.cttz.i33(i33 [[X:%.*]], i1 false), !range [[RNG1]]
 ; CHECK-NEXT:    store i33 [[TZ]], ptr [[P:%.*]], align 4
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i33 [[TZ]], 16
 ; CHECK-NEXT:    ret i1 [[CMP]]
@@ -493,7 +493,7 @@
 
 define i1 @ctpop_ugt_bitwidth_minus_one_i8(i8 %x, ptr %p) {
 ; CHECK-LABEL: @ctpop_ugt_bitwidth_minus_one_i8(
-; CHECK-NEXT:    [[POP:%.*]] = tail call i8 @llvm.ctpop.i8(i8 [[X:%.*]]), [[RNG2:!range !.*]]
+; CHECK-NEXT:    [[POP:%.*]] = tail call i8 @llvm.ctpop.i8(i8 [[X:%.*]]), !range [[RNG2:![0-9]+]]
 ; CHECK-NEXT:    store i8 [[POP]], ptr [[P:%.*]], align 1
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[X]], -1
 ; CHECK-NEXT:    ret i1 [[CMP]]
@@ -513,3 +513,107 @@
   %cmp = icmp ult <2 x i32> %pop, <i32 32, i32 32>
   ret <2 x i1> %cmp
 }
+
+define i1 @trunc_cttz_eq_other_i33_i15(i33 %x) {
+; CHECK-LABEL: @trunc_cttz_eq_other_i33_i15(
+; CHECK-NEXT:    [[TMP1:%.*]] = and i33 [[X:%.*]], 31
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i33 [[TMP1]], 16
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %tz = tail call i33 @llvm.cttz.i33(i33 %x, i1 false)
+  %trunc = trunc i33 %tz to i15
+  %cmp = icmp eq i15 %trunc, 4
+  ret i1 %cmp
+}
+
+define i1 @trunc_cttz_ugt_other_i33_i15(i33 %x) {
+; CHECK-LABEL: @trunc_cttz_ugt_other_i33_i15(
+; CHECK-NEXT:    [[TMP1:%.*]] = and i33 [[X:%.*]], 15
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i33 [[TMP1]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %tz = tail call i33 @llvm.cttz.i33(i33 %x, i1 false)
+  %trunc = trunc i33 %tz to i15
+  %cmp = icmp ugt i15 %trunc, 3
+  ret i1 %cmp
+}
+
+define i1 @trunc_cttz_ult_other_i33_i15(i33 %x) {
+; CHECK-LABEL: @trunc_cttz_ult_other_i33_i15(
+; CHECK-NEXT:    [[TMP1:%.*]] = and i33 [[X:%.*]], 127
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i33 [[TMP1]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %tz = tail call i33 @llvm.cttz.i33(i33 %x, i1 false)
+  %trunc = trunc i33 %tz to i15
+  %cmp = icmp ult i15 %trunc, 7
+  ret i1 %cmp
+}
+
+define i1 @trunc_ctlz_ugt_zero_i32(i32 %x) {
+; CHECK-LABEL: @trunc_ctlz_ugt_zero_i32(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i32 [[X:%.*]], -1
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %lz = tail call i32 @llvm.ctlz.i32(i32 %x, i1 false)
+  %trunc = trunc i32 %lz to i15
+  %cmp = icmp ugt i15 %trunc, 0
+  ret i1 %cmp
+}
+
+define i1 @trunc_ctlz_ugt_one_i32(i32 %x) {
+; CHECK-LABEL: @trunc_ctlz_ugt_one_i32(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[X:%.*]], 1073741824
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %lz = tail call i32 @llvm.ctlz.i32(i32 %x, i1 false)
+  %trunc = trunc i32 %lz to i15
+  %cmp = icmp ugt i15 %trunc, 1
+  ret i1 %cmp
+}
+
+define i1 @trunc_ctlz_ugt_other_i32(i32 %x) {
+; CHECK-LABEL: @trunc_ctlz_ugt_other_i32(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[X:%.*]], 134217728
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %lz = tail call i32 @llvm.ctlz.i32(i32 %x, i1 false)
+  %trunc = trunc i32 %lz to i15
+  %cmp = icmp ugt i15 %trunc, 4
+  ret i1 %cmp
+}
+
+define i1 @trunc_ctpop_eq_zero_i11(i11 %x) {
+; CHECK-LABEL: @trunc_ctpop_eq_zero_i11(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i11 [[X:%.*]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %pop = tail call i11 @llvm.ctpop.i11(i11 %x)
+  %trunc = trunc i11 %pop to i5
+  %cmp = icmp eq i5 %trunc, 0
+  ret i1 %cmp
+}
+
+define i1 @trunc_ctpop_eq_bitwidth_i8(i8 %x) {
+; CHECK-LABEL: @trunc_ctpop_eq_bitwidth_i8(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[X:%.*]], -1
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %pop = tail call i8 @llvm.ctpop.i8(i8 %x)
+  %trunc = trunc i8 %pop to i5
+  %cmp = icmp eq i5 %trunc, 8
+  ret i1 %cmp
+}
+
+define i1 @trunc_negative_destbits_not_enough(i33 %x) {
+; CHECK-LABEL: @trunc_negative_destbits_not_enough(
+; CHECK-NEXT:    [[TZ:%.*]] = tail call i33 @llvm.cttz.i33(i33 [[X:%.*]], i1 false), !range [[RNG1]]
+; CHECK-NEXT:    [[TRUNC:%.*]] = trunc i33 [[TZ]] to i4
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i4 [[TRUNC]], 7
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %tz = tail call i33 @llvm.cttz.i33(i33 %x, i1 false)
+  %trunc = trunc i33 %tz to i4
+  %cmp = icmp ult i4 %trunc, 7
+  ret i1 %cmp
+}