[llvm] d479849 - [InstCombine] Fold `(x == y) ? 0 : (x > y ? 1 : -1)` into `ucmp/scmp(x,y)` (#107314)
via llvm-commits
llvm-commits at lists.llvm.org
Mon Sep 23 07:41:26 PDT 2024
Author: Volodymyr Vasylkun
Date: 2024-09-23T15:41:22+01:00
New Revision: d4798498c4a30efb03eebb56415a69fa60107414
URL: https://github.com/llvm/llvm-project/commit/d4798498c4a30efb03eebb56415a69fa60107414
DIFF: https://github.com/llvm/llvm-project/commit/d4798498c4a30efb03eebb56415a69fa60107414.diff
LOG: [InstCombine] Fold `(x == y) ? 0 : (x > y ? 1 : -1)` into `ucmp/scmp(x,y)` (#107314)
This also handles commuted cases of the same fold, with either the
condition or the true/false values of the inner select being swapped.
Added:
Modified:
llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
llvm/test/Transforms/InstCombine/compare-3way.ll
llvm/test/Transforms/InstCombine/scmp.ll
llvm/test/Transforms/InstCombine/select-select.ll
llvm/test/Transforms/InstCombine/sink_to_unreachable.ll
llvm/test/Transforms/InstCombine/ucmp.ll
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
index 66f7c4592457c2..7476db9ee38f45 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -3551,9 +3551,7 @@ Instruction *InstCombinerImpl::foldSelectToCmp(SelectInst &SI) {
Pred = ICmpInst::getSwappedPredicate(Pred);
std::swap(LHS, RHS);
}
-
- Intrinsic::ID IID =
- ICmpInst::isSigned(Pred) ? Intrinsic::scmp : Intrinsic::ucmp;
+ bool IsSigned = ICmpInst::isSigned(Pred);
bool Replace = false;
ICmpInst::Predicate ExtendedCmpPredicate;
@@ -3575,6 +3573,32 @@ Instruction *InstCombinerImpl::foldSelectToCmp(SelectInst &SI) {
ICmpInst::getSwappedPredicate(ExtendedCmpPredicate) == Pred))
Replace = true;
+ // (x == y) ? 0 : (x > y ? 1 : -1)
+ ICmpInst::Predicate FalseBranchSelectPredicate;
+ const APInt *InnerTV, *InnerFV;
+ if (Pred == ICmpInst::ICMP_EQ && match(TV, m_Zero()) &&
+ match(FV, m_Select(m_c_ICmp(FalseBranchSelectPredicate, m_Specific(LHS),
+ m_Specific(RHS)),
+ m_APInt(InnerTV), m_APInt(InnerFV)))) {
+ if (!ICmpInst::isGT(FalseBranchSelectPredicate)) {
+ FalseBranchSelectPredicate =
+ ICmpInst::getSwappedPredicate(FalseBranchSelectPredicate);
+ std::swap(LHS, RHS);
+ }
+
+ if (!InnerTV->isOne()) {
+ std::swap(InnerTV, InnerFV);
+ std::swap(LHS, RHS);
+ }
+
+ if (ICmpInst::isGT(FalseBranchSelectPredicate) && InnerTV->isOne() &&
+ InnerFV->isAllOnes()) {
+ IsSigned = ICmpInst::isSigned(FalseBranchSelectPredicate);
+ Replace = true;
+ }
+ }
+
+ Intrinsic::ID IID = IsSigned ? Intrinsic::scmp : Intrinsic::ucmp;
if (Replace)
return replaceInstUsesWith(
SI, Builder.CreateIntrinsic(SI.getType(), IID, {LHS, RHS}));
diff --git a/llvm/test/Transforms/InstCombine/compare-3way.ll b/llvm/test/Transforms/InstCombine/compare-3way.ll
index e2067368fb4c3e..5d443cd45238c7 100644
--- a/llvm/test/Transforms/InstCombine/compare-3way.ll
+++ b/llvm/test/Transforms/InstCombine/compare-3way.ll
@@ -15,8 +15,7 @@ define void @test_low_sgt(i64 %a, i64 %b) {
; CHECK: normal:
; CHECK-NEXT: ret void
; CHECK: unreached:
-; CHECK-NEXT: [[EQ:%.*]] = icmp ne i64 [[A]], [[B]]
-; CHECK-NEXT: [[RESULT:%.*]] = zext i1 [[EQ]] to i32
+; CHECK-NEXT: [[RESULT:%.*]] = call i32 @llvm.scmp.i32.i64(i64 [[A]], i64 [[B]])
; CHECK-NEXT: call void @use(i32 [[RESULT]])
; CHECK-NEXT: ret void
;
@@ -62,10 +61,7 @@ define void @test_low_sge(i64 %a, i64 %b) {
; CHECK: normal:
; CHECK-NEXT: ret void
; CHECK: unreached:
-; CHECK-NEXT: [[EQ:%.*]] = icmp eq i64 [[A]], [[B]]
-; CHECK-NEXT: [[SLT:%.*]] = icmp slt i64 [[A]], [[B]]
-; CHECK-NEXT: [[DOT:%.*]] = select i1 [[SLT]], i32 -1, i32 1
-; CHECK-NEXT: [[RESULT:%.*]] = select i1 [[EQ]], i32 0, i32 [[DOT]]
+; CHECK-NEXT: [[RESULT:%.*]] = call i32 @llvm.scmp.i32.i64(i64 [[A]], i64 [[B]])
; CHECK-NEXT: call void @use(i32 [[RESULT]])
; CHECK-NEXT: ret void
;
@@ -114,8 +110,7 @@ define void @test_low_ne(i64 %a, i64 %b) {
; CHECK: normal:
; CHECK-NEXT: ret void
; CHECK: unreached:
-; CHECK-NEXT: [[EQ:%.*]] = icmp ne i64 [[A]], [[B]]
-; CHECK-NEXT: [[RESULT:%.*]] = zext i1 [[EQ]] to i32
+; CHECK-NEXT: [[RESULT:%.*]] = call i32 @llvm.scmp.i32.i64(i64 [[A]], i64 [[B]])
; CHECK-NEXT: call void @use(i32 [[RESULT]])
; CHECK-NEXT: ret void
;
@@ -212,8 +207,7 @@ define void @test_mid_sge(i64 %a, i64 %b) {
; CHECK: normal:
; CHECK-NEXT: ret void
; CHECK: unreached:
-; CHECK-NEXT: [[EQ:%.*]] = icmp ne i64 [[A]], [[B]]
-; CHECK-NEXT: [[RESULT:%.*]] = zext i1 [[EQ]] to i32
+; CHECK-NEXT: [[RESULT:%.*]] = call i32 @llvm.scmp.i32.i64(i64 [[A]], i64 [[B]])
; CHECK-NEXT: call void @use(i32 [[RESULT]])
; CHECK-NEXT: ret void
;
@@ -238,10 +232,7 @@ define void @test_mid_sle(i64 %a, i64 %b) {
; CHECK: normal:
; CHECK-NEXT: ret void
; CHECK: unreached:
-; CHECK-NEXT: [[EQ:%.*]] = icmp eq i64 [[A]], [[B]]
-; CHECK-NEXT: [[SLT:%.*]] = icmp slt i64 [[A]], [[B]]
-; CHECK-NEXT: [[DOT:%.*]] = select i1 [[SLT]], i32 -1, i32 1
-; CHECK-NEXT: [[RESULT:%.*]] = select i1 [[EQ]], i32 0, i32 [[DOT]]
+; CHECK-NEXT: [[RESULT:%.*]] = call i32 @llvm.scmp.i32.i64(i64 [[A]], i64 [[B]])
; CHECK-NEXT: call void @use(i32 [[RESULT]])
; CHECK-NEXT: ret void
;
@@ -266,9 +257,8 @@ define void @test_mid_ne(i64 %a, i64 %b) {
; CHECK: normal:
; CHECK-NEXT: ret void
; CHECK: unreached:
-; CHECK-NEXT: [[SLT:%.*]] = icmp slt i64 [[A]], [[B]]
-; CHECK-NEXT: [[DOT:%.*]] = select i1 [[SLT]], i32 -1, i32 1
-; CHECK-NEXT: call void @use(i32 [[DOT]])
+; CHECK-NEXT: [[RESULT:%.*]] = call i32 @llvm.scmp.i32.i64(i64 [[A]], i64 [[B]])
+; CHECK-NEXT: call void @use(i32 [[RESULT]])
; CHECK-NEXT: ret void
;
%eq = icmp eq i64 %a, %b
@@ -338,10 +328,7 @@ define void @test_high_slt(i64 %a, i64 %b) {
; CHECK: normal:
; CHECK-NEXT: ret void
; CHECK: unreached:
-; CHECK-NEXT: [[EQ:%.*]] = icmp eq i64 [[A]], [[B]]
-; CHECK-NEXT: [[SLT:%.*]] = icmp slt i64 [[A]], [[B]]
-; CHECK-NEXT: [[DOT:%.*]] = select i1 [[SLT]], i32 -1, i32 1
-; CHECK-NEXT: [[RESULT:%.*]] = select i1 [[EQ]], i32 0, i32 [[DOT]]
+; CHECK-NEXT: [[RESULT:%.*]] = call i32 @llvm.scmp.i32.i64(i64 [[A]], i64 [[B]])
; CHECK-NEXT: call void @use(i32 [[RESULT]])
; CHECK-NEXT: ret void
;
@@ -389,10 +376,7 @@ define void @test_high_sle(i64 %a, i64 %b) {
; CHECK: normal:
; CHECK-NEXT: ret void
; CHECK: unreached:
-; CHECK-NEXT: [[EQ:%.*]] = icmp eq i64 [[A]], [[B]]
-; CHECK-NEXT: [[SLT:%.*]] = icmp slt i64 [[A]], [[B]]
-; CHECK-NEXT: [[DOT:%.*]] = select i1 [[SLT]], i32 -1, i32 1
-; CHECK-NEXT: [[RESULT:%.*]] = select i1 [[EQ]], i32 0, i32 [[DOT]]
+; CHECK-NEXT: [[RESULT:%.*]] = call i32 @llvm.scmp.i32.i64(i64 [[A]], i64 [[B]])
; CHECK-NEXT: call void @use(i32 [[RESULT]])
; CHECK-NEXT: ret void
;
@@ -417,10 +401,7 @@ define void @test_high_ne(i64 %a, i64 %b) {
; CHECK: normal:
; CHECK-NEXT: ret void
; CHECK: unreached:
-; CHECK-NEXT: [[EQ:%.*]] = icmp eq i64 [[A]], [[B]]
-; CHECK-NEXT: [[SLT:%.*]] = icmp slt i64 [[A]], [[B]]
-; CHECK-NEXT: [[DOT:%.*]] = select i1 [[SLT]], i32 -1, i32 1
-; CHECK-NEXT: [[RESULT:%.*]] = select i1 [[EQ]], i32 0, i32 [[DOT]]
+; CHECK-NEXT: [[RESULT:%.*]] = call i32 @llvm.scmp.i32.i64(i64 [[A]], i64 [[B]])
; CHECK-NEXT: call void @use(i32 [[RESULT]])
; CHECK-NEXT: ret void
;
diff --git a/llvm/test/Transforms/InstCombine/scmp.ll b/llvm/test/Transforms/InstCombine/scmp.ll
index 123bc647462337..2140a59de3fa90 100644
--- a/llvm/test/Transforms/InstCombine/scmp.ll
+++ b/llvm/test/Transforms/InstCombine/scmp.ll
@@ -343,3 +343,133 @@ define i8 @scmp_from_select_gt_and_lt(i32 %x, i32 %y) {
%r = select i1 %gt, i8 1, i8 %lt
ret i8 %r
}
+
+; (x == y) ? 0 : (x s> y ? 1 : -1) into scmp(x, y)
+define i8 @scmp_from_select_eq_and_gt(i32 %x, i32 %y) {
+; CHECK-LABEL: define i8 @scmp_from_select_eq_and_gt(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[R:%.*]] = call i8 @llvm.scmp.i8.i32(i32 [[X]], i32 [[Y]])
+; CHECK-NEXT: ret i8 [[R]]
+;
+ %eq = icmp eq i32 %x, %y
+ %gt = icmp sgt i32 %x, %y
+ %sel1 = select i1 %gt, i8 1, i8 -1
+ %r = select i1 %eq, i8 0, i8 %sel1
+ ret i8 %r
+}
+
+define i8 @scmp_from_select_eq_and_gt_inverse(i32 %x, i32 %y) {
+; CHECK-LABEL: define i8 @scmp_from_select_eq_and_gt_inverse(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[R:%.*]] = call i8 @llvm.scmp.i8.i32(i32 [[X]], i32 [[Y]])
+; CHECK-NEXT: ret i8 [[R]]
+;
+ %ne = icmp ne i32 %x, %y
+ %gt = icmp sgt i32 %x, %y
+ %sel1 = select i1 %gt, i8 1, i8 -1
+ %r = select i1 %ne, i8 %sel1, i8 0
+ ret i8 %r
+}
+
+define <4 x i8> @scmp_from_select_eq_and_gt_vec(<4 x i32> %x, <4 x i32> %y) {
+; CHECK-LABEL: define <4 x i8> @scmp_from_select_eq_and_gt_vec(
+; CHECK-SAME: <4 x i32> [[X:%.*]], <4 x i32> [[Y:%.*]]) {
+; CHECK-NEXT: [[R:%.*]] = call <4 x i8> @llvm.scmp.v4i8.v4i32(<4 x i32> [[X]], <4 x i32> [[Y]])
+; CHECK-NEXT: ret <4 x i8> [[R]]
+;
+ %eq = icmp eq <4 x i32> %x, %y
+ %gt = icmp sgt <4 x i32> %x, %y
+ %sel1 = select <4 x i1> %gt, <4 x i8> splat(i8 1), <4 x i8> splat(i8 -1)
+ %r = select <4 x i1> %eq, <4 x i8> splat(i8 0), <4 x i8> %sel1
+ ret <4 x i8> %r
+}
+
+define i8 @scmp_from_select_eq_and_gt_commuted1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i8 @scmp_from_select_eq_and_gt_commuted1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[R:%.*]] = call i8 @llvm.scmp.i8.i32(i32 [[Y]], i32 [[X]])
+; CHECK-NEXT: ret i8 [[R]]
+;
+ %eq = icmp eq i32 %x, %y
+ %gt = icmp slt i32 %x, %y
+ %sel1 = select i1 %gt, i8 1, i8 -1
+ %r = select i1 %eq, i8 0, i8 %sel1
+ ret i8 %r
+}
+
+define i8 @scmp_from_select_eq_and_gt_commuted2(i32 %x, i32 %y) {
+; CHECK-LABEL: define i8 @scmp_from_select_eq_and_gt_commuted2(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[R:%.*]] = call i8 @llvm.scmp.i8.i32(i32 [[Y]], i32 [[X]])
+; CHECK-NEXT: ret i8 [[R]]
+;
+ %eq = icmp eq i32 %x, %y
+ %gt = icmp sgt i32 %x, %y
+ %sel1 = select i1 %gt, i8 -1, i8 1
+ %r = select i1 %eq, i8 0, i8 %sel1
+ ret i8 %r
+}
+
+define i8 @scmp_from_select_eq_and_gt_commuted3(i32 %x, i32 %y) {
+; CHECK-LABEL: define i8 @scmp_from_select_eq_and_gt_commuted3(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[R:%.*]] = call i8 @llvm.scmp.i8.i32(i32 [[X]], i32 [[Y]])
+; CHECK-NEXT: ret i8 [[R]]
+;
+ %eq = icmp eq i32 %x, %y
+ %gt = icmp slt i32 %x, %y
+ %sel1 = select i1 %gt, i8 -1, i8 1
+ %r = select i1 %eq, i8 0, i8 %sel1
+ ret i8 %r
+}
+
+; Negative test: true value of outer select is not zero
+define i8 @scmp_from_select_eq_and_gt_neg1(i32 %x, i32 %y) {
+; CHECK-LABEL: define i8 @scmp_from_select_eq_and_gt_neg1(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[EQ:%.*]] = icmp eq i32 [[X]], [[Y]]
+; CHECK-NEXT: [[GT:%.*]] = icmp sgt i32 [[X]], [[Y]]
+; CHECK-NEXT: [[SEL1:%.*]] = select i1 [[GT]], i8 1, i8 -1
+; CHECK-NEXT: [[R:%.*]] = select i1 [[EQ]], i8 5, i8 [[SEL1]]
+; CHECK-NEXT: ret i8 [[R]]
+;
+ %eq = icmp eq i32 %x, %y
+ %gt = icmp sgt i32 %x, %y
+ %sel1 = select i1 %gt, i8 1, i8 -1
+ %r = select i1 %eq, i8 5, i8 %sel1
+ ret i8 %r
+}
+
+; Negative test: true value of inner select is not 1 or -1
+define i8 @scmp_from_select_eq_and_gt_neg2(i32 %x, i32 %y) {
+; CHECK-LABEL: define i8 @scmp_from_select_eq_and_gt_neg2(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[EQ:%.*]] = icmp eq i32 [[X]], [[Y]]
+; CHECK-NEXT: [[GT:%.*]] = icmp sgt i32 [[X]], [[Y]]
+; CHECK-NEXT: [[SEL1:%.*]] = select i1 [[GT]], i8 2, i8 -1
+; CHECK-NEXT: [[R:%.*]] = select i1 [[EQ]], i8 0, i8 [[SEL1]]
+; CHECK-NEXT: ret i8 [[R]]
+;
+ %eq = icmp eq i32 %x, %y
+ %gt = icmp sgt i32 %x, %y
+ %sel1 = select i1 %gt, i8 2, i8 -1
+ %r = select i1 %eq, i8 0, i8 %sel1
+ ret i8 %r
+}
+
+; Negative test: false value of inner select is not 1 or -1
+define i8 @scmp_from_select_eq_and_gt_neg3(i32 %x, i32 %y) {
+; CHECK-LABEL: define i8 @scmp_from_select_eq_and_gt_neg3(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[EQ:%.*]] = icmp eq i32 [[X]], [[Y]]
+; CHECK-NEXT: [[GT:%.*]] = icmp sgt i32 [[X]], [[Y]]
+; CHECK-NEXT: [[SEL1:%.*]] = select i1 [[GT]], i8 1, i8 22
+; CHECK-NEXT: [[R:%.*]] = select i1 [[EQ]], i8 0, i8 [[SEL1]]
+; CHECK-NEXT: ret i8 [[R]]
+;
+ %eq = icmp eq i32 %x, %y
+ %gt = icmp sgt i32 %x, %y
+ %sel1 = select i1 %gt, i8 1, i8 22
+ %r = select i1 %eq, i8 0, i8 %sel1
+ ret i8 %r
+}
diff --git a/llvm/test/Transforms/InstCombine/select-select.ll b/llvm/test/Transforms/InstCombine/select-select.ll
index 1feae5ab504dcf..94e88c2f6cbe6c 100644
--- a/llvm/test/Transforms/InstCombine/select-select.ll
+++ b/llvm/test/Transforms/InstCombine/select-select.ll
@@ -177,10 +177,7 @@ define <2 x i8> @sel_shuf_narrowing_commute2(<4 x i8> %x, <4 x i8> %y, <2 x i8>
define i8 @strong_order_cmp_slt_eq(i32 %a, i32 %b) {
; CHECK-LABEL: @strong_order_cmp_slt_eq(
-; CHECK-NEXT: [[CMP_LT:%.*]] = icmp slt i32 [[A:%.*]], [[B:%.*]]
-; CHECK-NEXT: [[SEL_LT:%.*]] = select i1 [[CMP_LT]], i8 -1, i8 1
-; CHECK-NEXT: [[CMP_EQ:%.*]] = icmp eq i32 [[A]], [[B]]
-; CHECK-NEXT: [[SEL_EQ:%.*]] = select i1 [[CMP_EQ]], i8 0, i8 [[SEL_LT]]
+; CHECK-NEXT: [[SEL_EQ:%.*]] = call i8 @llvm.scmp.i8.i32(i32 [[A:%.*]], i32 [[B:%.*]])
; CHECK-NEXT: ret i8 [[SEL_EQ]]
;
%cmp.lt = icmp slt i32 %a, %b
@@ -192,10 +189,7 @@ define i8 @strong_order_cmp_slt_eq(i32 %a, i32 %b) {
define i8 @strong_order_cmp_ult_eq(i32 %a, i32 %b) {
; CHECK-LABEL: @strong_order_cmp_ult_eq(
-; CHECK-NEXT: [[CMP_LT:%.*]] = icmp ult i32 [[A:%.*]], [[B:%.*]]
-; CHECK-NEXT: [[SEL_LT:%.*]] = select i1 [[CMP_LT]], i8 -1, i8 1
-; CHECK-NEXT: [[CMP_EQ:%.*]] = icmp eq i32 [[A]], [[B]]
-; CHECK-NEXT: [[SEL_EQ:%.*]] = select i1 [[CMP_EQ]], i8 0, i8 [[SEL_LT]]
+; CHECK-NEXT: [[SEL_EQ:%.*]] = call i8 @llvm.ucmp.i8.i32(i32 [[A:%.*]], i32 [[B:%.*]])
; CHECK-NEXT: ret i8 [[SEL_EQ]]
;
%cmp.lt = icmp ult i32 %a, %b
@@ -252,10 +246,7 @@ define i8 @strong_order_cmp_slt_ult_wrong_pred(i32 %a, i32 %b) {
define i8 @strong_order_cmp_sgt_eq(i32 %a, i32 %b) {
; CHECK-LABEL: @strong_order_cmp_sgt_eq(
-; CHECK-NEXT: [[CMP_GT:%.*]] = icmp sgt i32 [[A:%.*]], [[B:%.*]]
-; CHECK-NEXT: [[SEL_GT:%.*]] = select i1 [[CMP_GT]], i8 1, i8 -1
-; CHECK-NEXT: [[CMP_EQ:%.*]] = icmp eq i32 [[A]], [[B]]
-; CHECK-NEXT: [[SEL_EQ:%.*]] = select i1 [[CMP_EQ]], i8 0, i8 [[SEL_GT]]
+; CHECK-NEXT: [[SEL_EQ:%.*]] = call i8 @llvm.scmp.i8.i32(i32 [[A:%.*]], i32 [[B:%.*]])
; CHECK-NEXT: ret i8 [[SEL_EQ]]
;
%cmp.gt = icmp sgt i32 %a, %b
@@ -267,10 +258,7 @@ define i8 @strong_order_cmp_sgt_eq(i32 %a, i32 %b) {
define i8 @strong_order_cmp_ugt_eq(i32 %a, i32 %b) {
; CHECK-LABEL: @strong_order_cmp_ugt_eq(
-; CHECK-NEXT: [[CMP_GT:%.*]] = icmp ugt i32 [[A:%.*]], [[B:%.*]]
-; CHECK-NEXT: [[SEL_GT:%.*]] = select i1 [[CMP_GT]], i8 1, i8 -1
-; CHECK-NEXT: [[CMP_EQ:%.*]] = icmp eq i32 [[A]], [[B]]
-; CHECK-NEXT: [[SEL_EQ:%.*]] = select i1 [[CMP_EQ]], i8 0, i8 [[SEL_GT]]
+; CHECK-NEXT: [[SEL_EQ:%.*]] = call i8 @llvm.ucmp.i8.i32(i32 [[A:%.*]], i32 [[B:%.*]])
; CHECK-NEXT: ret i8 [[SEL_EQ]]
;
%cmp.gt = icmp ugt i32 %a, %b
@@ -395,9 +383,7 @@ define i8 @strong_order_cmp_slt_eq_slt_not_oneuse(i32 %a, i32 %b) {
; CHECK-LABEL: @strong_order_cmp_slt_eq_slt_not_oneuse(
; CHECK-NEXT: [[CMP_LT:%.*]] = icmp slt i32 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: call void @use1(i1 [[CMP_LT]])
-; CHECK-NEXT: [[SEL_LT:%.*]] = select i1 [[CMP_LT]], i8 -1, i8 1
-; CHECK-NEXT: [[CMP_EQ:%.*]] = icmp eq i32 [[A]], [[B]]
-; CHECK-NEXT: [[SEL_EQ:%.*]] = select i1 [[CMP_EQ]], i8 0, i8 [[SEL_LT]]
+; CHECK-NEXT: [[SEL_EQ:%.*]] = call i8 @llvm.scmp.i8.i32(i32 [[A]], i32 [[B]])
; CHECK-NEXT: ret i8 [[SEL_EQ]]
;
%cmp.lt = icmp slt i32 %a, %b
@@ -410,11 +396,9 @@ define i8 @strong_order_cmp_slt_eq_slt_not_oneuse(i32 %a, i32 %b) {
define i8 @strong_order_cmp_sgt_eq_eq_not_oneuse(i32 %a, i32 %b) {
; CHECK-LABEL: @strong_order_cmp_sgt_eq_eq_not_oneuse(
-; CHECK-NEXT: [[CMP_GT:%.*]] = icmp sgt i32 [[A:%.*]], [[B:%.*]]
-; CHECK-NEXT: [[SEL_GT:%.*]] = select i1 [[CMP_GT]], i8 1, i8 -1
-; CHECK-NEXT: [[CMP_EQ:%.*]] = icmp eq i32 [[A]], [[B]]
+; CHECK-NEXT: [[CMP_EQ:%.*]] = icmp eq i32 [[A:%.*]], [[B:%.*]]
; CHECK-NEXT: call void @use1(i1 [[CMP_EQ]])
-; CHECK-NEXT: [[SEL_EQ:%.*]] = select i1 [[CMP_EQ]], i8 0, i8 [[SEL_GT]]
+; CHECK-NEXT: [[SEL_EQ:%.*]] = call i8 @llvm.scmp.i8.i32(i32 [[A]], i32 [[B]])
; CHECK-NEXT: ret i8 [[SEL_EQ]]
;
%cmp.gt = icmp sgt i32 %a, %b
diff --git a/llvm/test/Transforms/InstCombine/sink_to_unreachable.ll b/llvm/test/Transforms/InstCombine/sink_to_unreachable.ll
index 01510f8e9596b5..72aa6dc80df34c 100644
--- a/llvm/test/Transforms/InstCombine/sink_to_unreachable.ll
+++ b/llvm/test/Transforms/InstCombine/sink_to_unreachable.ll
@@ -10,8 +10,7 @@ define void @test_01(i32 %x, i32 %y) {
; CHECK-NEXT: [[C2:%.*]] = icmp slt i32 [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: br i1 [[C2]], label [[EXIT:%.*]], label [[UNREACHED:%.*]]
; CHECK: unreached:
-; CHECK-NEXT: [[C1:%.*]] = icmp ne i32 [[X]], [[Y]]
-; CHECK-NEXT: [[COMPARATOR:%.*]] = zext i1 [[C1]] to i32
+; CHECK-NEXT: [[COMPARATOR:%.*]] = call i32 @llvm.scmp.i32.i32(i32 [[X]], i32 [[Y]])
; CHECK-NEXT: call void @use(i32 [[COMPARATOR]])
; CHECK-NEXT: unreachable
; CHECK: exit:
@@ -42,8 +41,7 @@ define void @test_02(i32 %x, i32 %y) {
; CHECK-NEXT: [[C3:%.*]] = icmp sgt i32 [[X]], [[Y]]
; CHECK-NEXT: br i1 [[C3]], label [[EXIT]], label [[UNREACHED:%.*]]
; CHECK: unreached:
-; CHECK-NEXT: [[C1:%.*]] = icmp ne i32 [[X]], [[Y]]
-; CHECK-NEXT: [[COMPARATOR:%.*]] = zext i1 [[C1]] to i32
+; CHECK-NEXT: [[COMPARATOR:%.*]] = call i32 @llvm.scmp.i32.i32(i32 [[X]], i32 [[Y]])
; CHECK-NEXT: call void @use(i32 [[COMPARATOR]])
; CHECK-NEXT: unreachable
; CHECK: exit:
@@ -77,8 +75,7 @@ define i32 @test_03(i32 %x, i32 %y) {
; CHECK-NEXT: [[C3:%.*]] = icmp sgt i32 [[X]], [[Y]]
; CHECK-NEXT: br i1 [[C3]], label [[EXIT]], label [[UNREACHED:%.*]]
; CHECK: unreached:
-; CHECK-NEXT: [[C1:%.*]] = icmp ne i32 [[X]], [[Y]]
-; CHECK-NEXT: [[COMPARATOR:%.*]] = zext i1 [[C1]] to i32
+; CHECK-NEXT: [[COMPARATOR:%.*]] = call i32 @llvm.scmp.i32.i32(i32 [[X]], i32 [[Y]])
; CHECK-NEXT: ret i32 [[COMPARATOR]]
; CHECK: exit:
; CHECK-NEXT: ret i32 0
diff --git a/llvm/test/Transforms/InstCombine/ucmp.ll b/llvm/test/Transforms/InstCombine/ucmp.ll
index 13755f13bb0a11..2d5036019740cd 100644
--- a/llvm/test/Transforms/InstCombine/ucmp.ll
+++ b/llvm/test/Transforms/InstCombine/ucmp.ll
@@ -541,3 +541,17 @@ define i8 @ucmp_from_select_gt_and_lt(i32 %x, i32 %y) {
%r = select i1 %gt, i8 1, i8 %lt
ret i8 %r
}
+
+; (x == y) ? 0 : (x u> y ? 1 : -1) into ucmp(x, y)
+define i8 @scmp_from_select_eq_and_gt(i32 %x, i32 %y) {
+; CHECK-LABEL: define i8 @scmp_from_select_eq_and_gt(
+; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
+; CHECK-NEXT: [[R:%.*]] = call i8 @llvm.ucmp.i8.i32(i32 [[X]], i32 [[Y]])
+; CHECK-NEXT: ret i8 [[R]]
+;
+ %eq = icmp eq i32 %x, %y
+ %gt = icmp ugt i32 %x, %y
+ %sel1 = select i1 %gt, i8 1, i8 -1
+ %r = select i1 %eq, i8 0, i8 %sel1
+ ret i8 %r
+}
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