[InstCombine] Implement folds of icmp of UCMP/SCMP call and a constant #96118
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
@llvm/pr-subscribers-llvm-transforms Author: None (Poseydon42) ChangesThis patch handles various cases where an operation of the kind I wasn't sure what negative tests should be added here, if any are necessary at all. I'd love to hear your suggestions. Proofs (ucmp): https://alive2.llvm.org/ce/z/qQ7ihz Full diff: https://github.com/llvm/llvm-project/pull/96118.diff 3 Files Affected:
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 34b0f8b860497..cb0351259a1f9 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -3926,6 +3926,92 @@ foldICmpUSubSatOrUAddSatWithConstant(ICmpInst::Predicate Pred,
ConstantInt::get(Op1->getType(), EquivInt));
}
+static Instruction *
+foldICmpOfCmpIntrinsicWithConstant(ICmpInst::Predicate Pred, IntrinsicInst *I,
+ const APInt &C,
+ InstCombiner::BuilderTy &Builder) {
+ Intrinsic::ID IID = I->getIntrinsicID();
+ Value *LHS = I->getOperand(0);
+ Value *RHS = I->getOperand(1);
+
+ switch (Pred) {
+ case ICmpInst::ICMP_EQ:
+ if (C.isZero())
+ return new ICmpInst(Pred, LHS, RHS);
+ if (C.isOne())
+ return new ICmpInst(IID == Intrinsic::scmp ? ICmpInst::ICMP_SGT
+ : ICmpInst::ICMP_UGT,
+ LHS, RHS);
+ if (C.isAllOnes())
+ return new ICmpInst(IID == Intrinsic::scmp ? ICmpInst::ICMP_SLT
+ : ICmpInst::ICMP_ULT,
+ LHS, RHS);
+ break;
+
+ case ICmpInst::ICMP_NE:
+ if (C.isZero())
+ return new ICmpInst(Pred, LHS, RHS);
+ if (C.isOne())
+ return new ICmpInst(IID == Intrinsic::scmp ? ICmpInst::ICMP_SLE
+ : ICmpInst::ICMP_ULE,
+ LHS, RHS);
+ if (C.isAllOnes())
+ return new ICmpInst(IID == Intrinsic::scmp ? ICmpInst::ICMP_SGE
+ : ICmpInst::ICMP_UGE,
+ LHS, RHS);
+ break;
+
+ case ICmpInst::ICMP_SGT:
+ if (C.isAllOnes())
+ return new ICmpInst(IID == Intrinsic::scmp ? ICmpInst::ICMP_SGE
+ : ICmpInst::ICMP_UGE,
+ LHS, RHS);
+ if (C.isZero())
+ return new ICmpInst(IID == Intrinsic::scmp ? ICmpInst::ICMP_SGT
+ : ICmpInst::ICMP_UGT,
+ LHS, RHS);
+ break;
+
+ case ICmpInst::ICMP_SGE:
+ if (C.isZero())
+ return new ICmpInst(IID == Intrinsic::scmp ? ICmpInst::ICMP_SGE
+ : ICmpInst::ICMP_UGE,
+ LHS, RHS);
+ if (C.isOne())
+ return new ICmpInst(IID == Intrinsic::scmp ? ICmpInst::ICMP_SGT
+ : ICmpInst::ICMP_UGT,
+ LHS, RHS);
+ break;
+
+ case ICmpInst::ICMP_SLT:
+ if (C.isZero())
+ return new ICmpInst(IID == Intrinsic::scmp ? ICmpInst::ICMP_SLT
+ : ICmpInst::ICMP_ULT,
+ LHS, RHS);
+ if (C.isOne())
+ return new ICmpInst(IID == Intrinsic::scmp ? ICmpInst::ICMP_SLE
+ : ICmpInst::ICMP_ULE,
+ LHS, RHS);
+ break;
+
+ case llvm::ICmpInst::ICMP_SLE:
+ if (C.isZero())
+ return new ICmpInst(IID == Intrinsic::scmp ? ICmpInst::ICMP_SLE
+ : ICmpInst::ICMP_ULE,
+ LHS, RHS);
+ if (C.isAllOnes())
+ return new ICmpInst(IID == Intrinsic::scmp ? ICmpInst::ICMP_SLT
+ : ICmpInst::ICMP_ULT,
+ LHS, RHS);
+ break;
+
+ default:
+ return nullptr;
+ }
+
+ return nullptr;
+}
+
/// Fold an icmp with LLVM intrinsic and constant operand: icmp Pred II, C.
Instruction *InstCombinerImpl::foldICmpIntrinsicWithConstant(ICmpInst &Cmp,
IntrinsicInst *II,
@@ -3947,6 +4033,11 @@ Instruction *InstCombinerImpl::foldICmpIntrinsicWithConstant(ICmpInst &Cmp,
if (Instruction *R = foldCtpopPow2Test(Cmp, II, C, Builder, Q))
return R;
} break;
+ case Intrinsic::scmp:
+ case Intrinsic::ucmp:
+ if (auto *Folded = foldICmpOfCmpIntrinsicWithConstant(Pred, II, C, Builder))
+ return Folded;
+ break;
}
if (Cmp.isEquality())
diff --git a/llvm/test/Transforms/InstCombine/scmp.ll b/llvm/test/Transforms/InstCombine/scmp.ll
new file mode 100644
index 0000000000000..4f903a79afd5d
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/scmp.ll
@@ -0,0 +1,156 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt < %s -passes=instcombine -S | FileCheck %s
+
+define i1 @scmp_eq_0(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @scmp_eq_0(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.scmp(i32 %x, i32 %y)
+ %2 = icmp eq i8 %1, 0
+ ret i1 %2
+}
+
+define i1 @scmp_ne_0(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @scmp_ne_0(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.scmp(i32 %x, i32 %y)
+ %2 = icmp ne i8 %1, 0
+ ret i1 %2
+}
+
+define i1 @scmp_eq_1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @scmp_eq_1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp sgt i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.scmp(i32 %x, i32 %y)
+ %2 = icmp eq i8 %1, 1
+ ret i1 %2
+}
+
+define i1 @scmp_ne_1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @scmp_ne_1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp sle i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.scmp(i32 %x, i32 %y)
+ %2 = icmp ne i8 %1, 1
+ ret i1 %2
+}
+
+define i1 @scmp_eq_negative_1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @scmp_eq_negative_1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp slt i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.scmp(i32 %x, i32 %y)
+ %2 = icmp eq i8 %1, -1
+ ret i1 %2
+}
+
+define i1 @scmp_ne_negative_1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @scmp_ne_negative_1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp sge i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.scmp(i32 %x, i32 %y)
+ %2 = icmp ne i8 %1, -1
+ ret i1 %2
+}
+
+define i1 @scmp_sgt_0(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @scmp_sgt_0(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp sgt i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.scmp(i32 %x, i32 %y)
+ %2 = icmp sgt i8 %1, 0
+ ret i1 %2
+}
+
+define i1 @scmp_sgt_neg_1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @scmp_sgt_neg_1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp sge i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.scmp(i32 %x, i32 %y)
+ %2 = icmp sgt i8 %1, -1
+ ret i1 %2
+}
+
+define i1 @scmp_sge_0(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @scmp_sge_0(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp sge i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.scmp(i32 %x, i32 %y)
+ %2 = icmp sge i8 %1, 0
+ ret i1 %2
+}
+
+define i1 @scmp_sge_1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @scmp_sge_1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp sgt i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.scmp(i32 %x, i32 %y)
+ %2 = icmp sge i8 %1, 1
+ ret i1 %2
+}
+
+define i1 @scmp_slt_0(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @scmp_slt_0(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp slt i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.scmp(i32 %x, i32 %y)
+ %2 = icmp slt i8 %1, 0
+ ret i1 %2
+}
+
+define i1 @scmp_slt_1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @scmp_slt_1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp sle i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.scmp(i32 %x, i32 %y)
+ %2 = icmp slt i8 %1, 1
+ ret i1 %2
+}
+
+define i1 @scmp_sle_0(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @scmp_sle_0(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp sle i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.scmp(i32 %x, i32 %y)
+ %2 = icmp sle i8 %1, 0
+ ret i1 %2
+}
+
+define i1 @scmp_sle_neg_1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @scmp_sle_neg_1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp slt i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.scmp(i32 %x, i32 %y)
+ %2 = icmp sle i8 %1, -1
+ ret i1 %2
+}
diff --git a/llvm/test/Transforms/InstCombine/ucmp.ll b/llvm/test/Transforms/InstCombine/ucmp.ll
new file mode 100644
index 0000000000000..9ab67560c9117
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/ucmp.ll
@@ -0,0 +1,156 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt < %s -passes=instcombine -S | FileCheck %s
+
+define i1 @ucmp_eq_0(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @ucmp_eq_0(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.ucmp(i32 %x, i32 %y)
+ %2 = icmp eq i8 %1, 0
+ ret i1 %2
+}
+
+define i1 @ucmp_ne_0(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @ucmp_ne_0(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ne i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.ucmp(i32 %x, i32 %y)
+ %2 = icmp ne i8 %1, 0
+ ret i1 %2
+}
+
+define i1 @ucmp_eq_1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @ucmp_eq_1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ugt i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.ucmp(i32 %x, i32 %y)
+ %2 = icmp eq i8 %1, 1
+ ret i1 %2
+}
+
+define i1 @ucmp_ne_1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @ucmp_ne_1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ule i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.ucmp(i32 %x, i32 %y)
+ %2 = icmp ne i8 %1, 1
+ ret i1 %2
+}
+
+define i1 @ucmp_eq_negative_1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @ucmp_eq_negative_1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.ucmp(i32 %x, i32 %y)
+ %2 = icmp eq i8 %1, -1
+ ret i1 %2
+}
+
+define i1 @ucmp_ne_negative_1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @ucmp_ne_negative_1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp uge i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.ucmp(i32 %x, i32 %y)
+ %2 = icmp ne i8 %1, -1
+ ret i1 %2
+}
+
+define i1 @ucmp_sgt_0(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @ucmp_sgt_0(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ugt i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.ucmp(i32 %x, i32 %y)
+ %2 = icmp sgt i8 %1, 0
+ ret i1 %2
+}
+
+define i1 @ucmp_sgt_neg_1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @ucmp_sgt_neg_1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp uge i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.ucmp(i32 %x, i32 %y)
+ %2 = icmp sgt i8 %1, -1
+ ret i1 %2
+}
+
+define i1 @ucmp_sge_0(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @ucmp_sge_0(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp uge i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.ucmp(i32 %x, i32 %y)
+ %2 = icmp sge i8 %1, 0
+ ret i1 %2
+}
+
+define i1 @ucmp_sge_1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @ucmp_sge_1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ugt i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.ucmp(i32 %x, i32 %y)
+ %2 = icmp sge i8 %1, 1
+ ret i1 %2
+}
+
+define i1 @ucmp_slt_0(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @ucmp_slt_0(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.ucmp(i32 %x, i32 %y)
+ %2 = icmp slt i8 %1, 0
+ ret i1 %2
+}
+
+define i1 @ucmp_slt_1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @ucmp_slt_1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ule i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.ucmp(i32 %x, i32 %y)
+ %2 = icmp slt i8 %1, 1
+ ret i1 %2
+}
+
+define i1 @ucmp_sle_0(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @ucmp_sle_0(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ule i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.ucmp(i32 %x, i32 %y)
+ %2 = icmp sle i8 %1, 0
+ ret i1 %2
+}
+
+define i1 @ucmp_sle_neg_1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i1 @ucmp_sle_neg_1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[TMP2:%.*]] = icmp ult i32 [[X]], [[Y]]
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %1 = call i8 @llvm.ucmp(i32 %x, i32 %y)
+ %2 = icmp sle i8 %1, -1
+ ret i1 %2
+}
|
dc03-work
reviewed
Jun 20, 2024
dtcxzyw
reviewed
Jun 20, 2024
goldsteinn
reviewed
Jun 21, 2024
Co-authored-by: Nikita Popov <[email protected]>
AlexisPerry
pushed a commit
to llvm-project-tlp/llvm-project
that referenced
this pull request
Jul 9, 2024
llvm#96118) This patch handles various cases where an operation of the kind `icmp (ucmp/scmp x, y), constant` folds to `icmp x, y`. Another patch with cases where this operation folds to a constant (i.e. dumb cases like `icmp eq (cmp x, y), 4` should be published in a couple of days. I wasn't sure what negative tests should be added here, if any are necessary at all. I'd love to hear your suggestions. Proofs (ucmp): https://alive2.llvm.org/ce/z/qQ7ihz Proofs (scmp): https://alive2.llvm.org/ce/z/cipKEn --------- Co-authored-by: Nikita Popov <[email protected]>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This patch handles various cases where an operation of the kind
icmp (ucmp/scmp x, y), constantfolds toicmp x, y. Another patch with cases where this operation folds to a constant (i.e. dumb cases likeicmp eq (cmp x, y), 4should be published in a couple of days.I wasn't sure what negative tests should be added here, if any are necessary at all. I'd love to hear your suggestions.
Proofs (ucmp): https://alive2.llvm.org/ce/z/qQ7ihz
Proofs (scmp): https://alive2.llvm.org/ce/z/cipKEn