[InstCombine] Introduce test for PR149858 (NFC)

1 files changed, 394 insertions, 0 deletions

diff --git a/llvm/test/Transforms/InstCombine/recurrence-binary-intrinsic.ll b/llvm/test/Transforms/InstCombine/recurrence-binary-intrinsic.ll
new file mode 100644
index 0000000..c637481
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/recurrence-binary-intrinsic.ll
@@ -0,0 +1,394 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -passes=instcombine -S < %s | FileCheck %s
+
+define i8 @simple_recurrence_intrinsic_smax(i8 %n, i8 %a, i8 %b) {
+; CHECK-LABEL: define i8 @simple_recurrence_intrinsic_smax(
+; CHECK-SAME: i8 [[N:%.*]], i8 [[A:%.*]], i8 [[B:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i8 [ [[IV_NEXT:%.*]], %[[LOOP]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT:    [[SMAX_ACC:%.*]] = phi i8 [ [[SMAX:%.*]], %[[LOOP]] ], [ [[A]], %[[ENTRY]] ]
+; CHECK-NEXT:    [[SMAX]] = call i8 @llvm.smax.i8(i8 [[SMAX_ACC]], i8 [[B]])
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw i8 [[IV]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i8 [[IV_NEXT]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP]], label %[[EXIT:.*]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret i8 [[SMAX]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i8 [ %iv.next, %loop ], [ 0, %entry ]
+  %smax.acc = phi i8 [ %smax, %loop ], [ %a, %entry ]
+  %smax = call i8 @llvm.smax.i8(i8 %smax.acc, i8 %b)
+  %iv.next = add nuw i8 %iv, 1
+  %cmp = icmp ult i8 %iv.next, %n
+  br i1 %cmp, label %loop, label %exit
+
+exit:
+  ret i8 %smax
+}
+
+define i8 @simple_recurrence_intrinsic_smin(i8 %n, i8 %a, i8 %b) {
+; CHECK-LABEL: define i8 @simple_recurrence_intrinsic_smin(
+; CHECK-SAME: i8 [[N:%.*]], i8 [[A:%.*]], i8 [[B:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i8 [ [[IV_NEXT:%.*]], %[[LOOP]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT:    [[SMIN_ACC:%.*]] = phi i8 [ [[SMIN:%.*]], %[[LOOP]] ], [ [[A]], %[[ENTRY]] ]
+; CHECK-NEXT:    [[SMIN]] = call i8 @llvm.smin.i8(i8 [[SMIN_ACC]], i8 [[B]])
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw i8 [[IV]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i8 [[IV_NEXT]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP]], label %[[EXIT:.*]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret i8 [[SMIN]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i8 [ %iv.next, %loop ], [ 0, %entry ]
+  %smin.acc = phi i8 [ %smin, %loop ], [ %a, %entry ]
+  %smin = call i8 @llvm.smin.i8(i8 %smin.acc, i8 %b)
+  %iv.next = add nuw i8 %iv, 1
+  %cmp = icmp ult i8 %iv.next, %n
+  br i1 %cmp, label %loop, label %exit
+
+exit:
+  ret i8 %smin
+}
+
+define i8 @simple_recurrence_intrinsic_umax(i8 %n, i8 %a, i8 %b) {
+; CHECK-LABEL: define i8 @simple_recurrence_intrinsic_umax(
+; CHECK-SAME: i8 [[N:%.*]], i8 [[A:%.*]], i8 [[B:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i8 [ [[IV_NEXT:%.*]], %[[LOOP]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT:    [[UMAX_ACC:%.*]] = phi i8 [ [[UMAX:%.*]], %[[LOOP]] ], [ [[A]], %[[ENTRY]] ]
+; CHECK-NEXT:    [[UMAX]] = call i8 @llvm.umax.i8(i8 [[UMAX_ACC]], i8 [[B]])
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw i8 [[IV]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i8 [[IV_NEXT]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP]], label %[[EXIT:.*]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret i8 [[UMAX]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i8 [ %iv.next, %loop ], [ 0, %entry ]
+  %umax.acc = phi i8 [ %umax, %loop ], [ %a, %entry ]
+  %umax = call i8 @llvm.umax.i8(i8 %umax.acc, i8 %b)
+  %iv.next = add nuw i8 %iv, 1
+  %cmp = icmp ult i8 %iv.next, %n
+  br i1 %cmp, label %loop, label %exit
+
+exit:
+  ret i8 %umax
+}
+
+define i8 @simple_recurrence_intrinsic_umin(i8 %n, i8 %a, i8 %b) {
+; CHECK-LABEL: define i8 @simple_recurrence_intrinsic_umin(
+; CHECK-SAME: i8 [[N:%.*]], i8 [[A:%.*]], i8 [[B:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i8 [ [[IV_NEXT:%.*]], %[[LOOP]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT:    [[UMIN_ACC:%.*]] = phi i8 [ [[UMIN:%.*]], %[[LOOP]] ], [ [[A]], %[[ENTRY]] ]
+; CHECK-NEXT:    [[UMIN]] = call i8 @llvm.umin.i8(i8 [[UMIN_ACC]], i8 [[B]])
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw i8 [[IV]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i8 [[IV_NEXT]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP]], label %[[EXIT:.*]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret i8 [[UMIN]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i8 [ %iv.next, %loop ], [ 0, %entry ]
+  %umin.acc = phi i8 [ %umin, %loop ], [ %a, %entry ]
+  %umin = call i8 @llvm.umin.i8(i8 %umin.acc, i8 %b)
+  %iv.next = add nuw i8 %iv, 1
+  %cmp = icmp ult i8 %iv.next, %n
+  br i1 %cmp, label %loop, label %exit
+
+exit:
+  ret i8 %umin
+}
+
+define float @simple_recurrence_intrinsic_maxnum(i32 %n, float %a, float %b) {
+; CHECK-LABEL: define float @simple_recurrence_intrinsic_maxnum(
+; CHECK-SAME: i32 [[N:%.*]], float [[A:%.*]], float [[B:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], %[[LOOP]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT:    [[FMAX_ACC:%.*]] = phi float [ [[FMAX:%.*]], %[[LOOP]] ], [ [[A]], %[[ENTRY]] ]
+; CHECK-NEXT:    [[FMAX]] = call float @llvm.maxnum.f32(float [[FMAX_ACC]], float [[B]])
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw i32 [[IV]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[IV_NEXT]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP]], label %[[EXIT:.*]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret float [[FMAX]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i32  [ %iv.next, %loop ], [ 0, %entry ]
+  %fmax.acc = phi float [ %fmax, %loop ], [ %a, %entry ]
+  %fmax = call float @llvm.maxnum.f32(float %fmax.acc, float %b)
+  %iv.next = add nuw i32 %iv, 1
+  %cmp = icmp ult i32 %iv.next, %n
+  br i1 %cmp, label %loop, label %exit
+exit:
+  ret float %fmax
+}
+
+define float @simple_recurrence_intrinsic_minnum(i32 %n, float %a, float %b) {
+; CHECK-LABEL: define float @simple_recurrence_intrinsic_minnum(
+; CHECK-SAME: i32 [[N:%.*]], float [[A:%.*]], float [[B:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], %[[LOOP]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT:    [[FMIN_ACC:%.*]] = phi float [ [[FMIN:%.*]], %[[LOOP]] ], [ [[A]], %[[ENTRY]] ]
+; CHECK-NEXT:    [[FMIN]] = call float @llvm.minnum.f32(float [[FMIN_ACC]], float [[B]])
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw i32 [[IV]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[IV_NEXT]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP]], label %[[EXIT:.*]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret float [[FMIN]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i32  [ %iv.next, %loop ], [ 0, %entry ]
+  %fmin.acc = phi float [ %fmin, %loop ], [ %a, %entry ]
+  %fmin = call float @llvm.minnum.f32(float %fmin.acc, float %b)
+  %iv.next = add nuw i32 %iv, 1
+  %cmp = icmp ult i32 %iv.next, %n
+  br i1 %cmp, label %loop, label %exit
+exit:
+  ret float %fmin
+}
+
+define float @simple_recurrence_intrinsic_maximum(i32 %n, float %a, float %b) {
+; CHECK-LABEL: define float @simple_recurrence_intrinsic_maximum(
+; CHECK-SAME: i32 [[N:%.*]], float [[A:%.*]], float [[B:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], %[[LOOP]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT:    [[FMAX_ACC:%.*]] = phi float [ [[FMAX:%.*]], %[[LOOP]] ], [ [[A]], %[[ENTRY]] ]
+; CHECK-NEXT:    [[FMAX]] = call nnan float @llvm.maximum.f32(float [[FMAX_ACC]], float [[B]])
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw i32 [[IV]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[IV_NEXT]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP]], label %[[EXIT:.*]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret float [[FMAX]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i32  [ %iv.next, %loop ], [ 0, %entry ]
+  %fmax.acc = phi float [ %fmax, %loop ], [ %a, %entry ]
+  %fmax = call nnan float @llvm.maximum.f32(float %fmax.acc, float %b)
+  %iv.next = add nuw i32 %iv, 1
+  %cmp = icmp ult i32 %iv.next, %n
+  br i1 %cmp, label %loop, label %exit
+exit:
+  ret float %fmax
+}
+
+define float @simple_recurrence_intrinsic_minimum(i32 %n, float %a, float %b) {
+; CHECK-LABEL: define float @simple_recurrence_intrinsic_minimum(
+; CHECK-SAME: i32 [[N:%.*]], float [[A:%.*]], float [[B:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], %[[LOOP]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT:    [[FMIN_ACC:%.*]] = phi float [ [[FMIN:%.*]], %[[LOOP]] ], [ [[A]], %[[ENTRY]] ]
+; CHECK-NEXT:    [[FMIN]] = call nnan float @llvm.minimum.f32(float [[FMIN_ACC]], float [[B]])
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw i32 [[IV]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[IV_NEXT]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP]], label %[[EXIT:.*]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret float [[FMIN]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i32  [ %iv.next, %loop ], [ 0, %entry ]
+  %fmin.acc = phi float [ %fmin, %loop ], [ %a, %entry ]
+  %fmin = call nnan float @llvm.minimum.f32(float %fmin.acc, float %b)
+  %iv.next = add nuw i32 %iv, 1
+  %cmp = icmp ult i32 %iv.next, %n
+  br i1 %cmp, label %loop, label %exit
+exit:
+  ret float %fmin
+}
+
+define float @simple_recurrence_intrinsic_maximumnum(i32 %n, float %a, float %b) {
+; CHECK-LABEL: define float @simple_recurrence_intrinsic_maximumnum(
+; CHECK-SAME: i32 [[N:%.*]], float [[A:%.*]], float [[B:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], %[[LOOP]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT:    [[FMAX_ACC:%.*]] = phi float [ [[FMAX:%.*]], %[[LOOP]] ], [ [[A]], %[[ENTRY]] ]
+; CHECK-NEXT:    [[FMAX]] = call nnan float @llvm.maximumnum.f32(float [[FMAX_ACC]], float [[B]])
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw i32 [[IV]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[IV_NEXT]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP]], label %[[EXIT:.*]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret float [[FMAX]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i32  [ %iv.next, %loop ], [ 0, %entry ]
+  %fmax.acc = phi float [ %fmax, %loop ], [ %a, %entry ]
+  %fmax = call nnan float @llvm.maximumnum.f32(float %fmax.acc, float %b)
+  %iv.next = add nuw i32 %iv, 1
+  %cmp = icmp ult i32 %iv.next, %n
+  br i1 %cmp, label %loop, label %exit
+exit:
+  ret float %fmax
+}
+
+define float @simple_recurrence_intrinsic_minimumnum(i32 %n, float %a, float %b) {
+; CHECK-LABEL: define float @simple_recurrence_intrinsic_minimumnum(
+; CHECK-SAME: i32 [[N:%.*]], float [[A:%.*]], float [[B:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ [[IV_NEXT:%.*]], %[[LOOP]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT:    [[FMIN_ACC:%.*]] = phi float [ [[FMIN:%.*]], %[[LOOP]] ], [ [[A]], %[[ENTRY]] ]
+; CHECK-NEXT:    [[FMIN]] = call nnan float @llvm.minimumnum.f32(float [[FMIN_ACC]], float [[B]])
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw i32 [[IV]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i32 [[IV_NEXT]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP]], label %[[EXIT:.*]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret float [[FMIN]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i32  [ %iv.next, %loop ], [ 0, %entry ]
+  %fmin.acc = phi float [ %fmin, %loop ], [ %a, %entry ]
+  %fmin = call nnan float @llvm.minimumnum.f32(float %fmin.acc, float %b)
+  %iv.next = add nuw i32 %iv, 1
+  %cmp = icmp ult i32 %iv.next, %n
+  br i1 %cmp, label %loop, label %exit
+exit:
+  ret float %fmin
+}
+
+define i8 @simple_recurrence_intrinsic_multiuse_phi(i8 %n, i8 %a, i8 %b) {
+; CHECK-LABEL: define i8 @simple_recurrence_intrinsic_multiuse_phi(
+; CHECK-SAME: i8 [[N:%.*]], i8 [[A:%.*]], i8 [[B:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i8 [ [[IV_NEXT:%.*]], %[[LOOP]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT:    [[UMAX_ACC:%.*]] = phi i8 [ [[UMAX:%.*]], %[[LOOP]] ], [ [[A]], %[[ENTRY]] ]
+; CHECK-NEXT:    call void @use(i8 [[UMAX_ACC]])
+; CHECK-NEXT:    [[UMAX]] = call i8 @llvm.umax.i8(i8 [[UMAX_ACC]], i8 [[B]])
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw i8 [[IV]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i8 [[IV_NEXT]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP]], label %[[EXIT:.*]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret i8 [[UMAX]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i8 [ %iv.next, %loop ], [ 0, %entry ]
+  %umax.acc = phi i8 [ %umax, %loop ], [ %a, %entry ]
+  call void @use(i8 %umax.acc)
+  %umax = call i8 @llvm.umax.i8(i8 %umax.acc, i8 %b)
+  %iv.next = add nuw i8 %iv, 1
+  %cmp = icmp ult i8 %iv.next, %n
+  br i1 %cmp, label %loop, label %exit
+
+exit:
+  ret i8 %umax
+}
+
+; Negative tests.
+
+define i8 @simple_recurrence_intrinsic_uadd_sat(i8 %n, i8 %a, i8 %b) {
+; CHECK-LABEL: define i8 @simple_recurrence_intrinsic_uadd_sat(
+; CHECK-SAME: i8 [[N:%.*]], i8 [[A:%.*]], i8 [[B:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i8 [ [[IV_NEXT:%.*]], %[[LOOP]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT:    [[UADD_SAT_ACC:%.*]] = phi i8 [ [[UADD_SAT:%.*]], %[[LOOP]] ], [ [[A]], %[[ENTRY]] ]
+; CHECK-NEXT:    [[UADD_SAT]] = call i8 @llvm.uadd.sat.i8(i8 [[UADD_SAT_ACC]], i8 [[B]])
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw i8 [[IV]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i8 [[IV_NEXT]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP]], label %[[EXIT:.*]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret i8 [[UADD_SAT]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i8 [ %iv.next, %loop ], [ 0, %entry ]
+  %uadd.sat.acc = phi i8 [ %uadd.sat, %loop ], [ %a, %entry ]
+  %uadd.sat = call i8 @llvm.uadd.sat.i8(i8 %uadd.sat.acc, i8 %b)
+  %iv.next = add nuw i8 %iv, 1
+  %cmp = icmp ult i8 %iv.next, %n
+  br i1 %cmp, label %loop, label %exit
+
+exit:
+  ret i8 %uadd.sat
+}
+
+define i8 @simple_recurrence_intrinsic_arg_loop_variant(i8 %n, i8 %a) {
+; CHECK-LABEL: define i8 @simple_recurrence_intrinsic_arg_loop_variant(
+; CHECK-SAME: i8 [[N:%.*]], i8 [[A:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[IV:%.*]] = phi i8 [ [[IV_NEXT:%.*]], %[[LOOP]] ], [ 0, %[[ENTRY]] ]
+; CHECK-NEXT:    [[UMAX_ACC:%.*]] = phi i8 [ [[UMAX:%.*]], %[[LOOP]] ], [ [[A]], %[[ENTRY]] ]
+; CHECK-NEXT:    [[B:%.*]] = xor i8 [[IV]], 42
+; CHECK-NEXT:    [[UMAX]] = call i8 @llvm.umax.i8(i8 [[UMAX_ACC]], i8 [[B]])
+; CHECK-NEXT:    [[IV_NEXT]] = add nuw i8 [[IV]], 1
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i8 [[IV_NEXT]], [[N]]
+; CHECK-NEXT:    br i1 [[CMP]], label %[[LOOP]], label %[[EXIT:.*]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    ret i8 [[UMAX]]
+;
+entry:
+  br label %loop
+
+loop:
+  %iv = phi i8 [ %iv.next, %loop ], [ 0, %entry ]
+  %umax.acc = phi i8 [ %umax, %loop ], [ %a, %entry ]
+  %b = xor i8 %iv, 42
+  %umax = call i8 @llvm.umax.i8(i8 %umax.acc, i8 %b)
+  %iv.next = add nuw i8 %iv, 1
+  %cmp = icmp ult i8 %iv.next, %n
+  br i1 %cmp, label %loop, label %exit
+
+exit:
+  ret i8 %umax
+}
+
+declare void @use(i8)