[ValueTracking] Add tests for using condition in select for non-zero analysis; NFC

Differential Revision: https://reviews.llvm.org/D147899

diff --git a/llvm/test/Analysis/ValueTracking/select-known-non-zero-const.ll b/llvm/test/Analysis/ValueTracking/select-known-non-zero-const.ll
new file mode 100644 (file)
index 0000000..1365cd5
--- /dev/null
+++ b/llvm/test/Analysis/ValueTracking/select-known-non-zero-const.ll
@@ -0,0 +1,388 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes=instsimplify -S | FileCheck %s
+
+declare void @llvm.assume(i1)
+define <2 x i1> @select_v_ne_z(<2 x i8> %v, <2 x i8> %yy) {
+; CHECK-LABEL: @select_v_ne_z(
+; CHECK-NEXT:    [[Y:%.*]] = or <2 x i8> [[YY:%.*]], <i8 1, i8 1>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne <2 x i8> [[V:%.*]], zeroinitializer
+; CHECK-NEXT:    [[S:%.*]] = select <2 x i1> [[CMP]], <2 x i8> [[V]], <2 x i8> [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq <2 x i8> [[S]], zeroinitializer
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %y = or <2 x i8> %yy, <i8 1, i8 1>
+  %cmp = icmp ne <2 x i8> %v, zeroinitializer
+  %s = select <2 x i1> %cmp, <2 x i8> %v, <2 x i8> %y
+  %r = icmp eq <2 x i8> %s, zeroinitializer
+  ret <2 x i1> %r
+}
+
+define i1 @select_v_ne_fail(i8 %v, i8 %y) {
+; CHECK-LABEL: @select_v_ne_fail(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i8 [[V:%.*]], 1
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp ne i8 %v, 1
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_eq_nz(i8 %v, i8 %y) {
+; CHECK-LABEL: @select_v_eq_nz(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 44, [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp eq i8 44, %v
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @inv_select_v_ugt_nz(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @inv_select_v_ugt_nz(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i8 14, [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[Y]], i8 [[V]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp ugt i8 14, %v
+  %s = select i1 %cmp, i8 %y, i8 %v
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @inv_select_v_ugt_fail(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @inv_select_v_ugt_fail(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i8 -2, [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[Y]], i8 [[V]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp ugt i8 -2, %v
+  %s = select i1 %cmp, i8 %y, i8 %v
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define <2 x i1> @select_v_ult(<2 x i8> %v, <2 x i8> %C, <2 x i8> %yy) {
+; CHECK-LABEL: @select_v_ult(
+; CHECK-NEXT:    [[Y:%.*]] = or <2 x i8> [[YY:%.*]], <i8 1, i8 1>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult <2 x i8> [[C:%.*]], [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select <2 x i1> [[CMP]], <2 x i8> [[V]], <2 x i8> [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq <2 x i8> [[S]], zeroinitializer
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %y = or <2 x i8> %yy, <i8 1, i8 1>
+  %cmp = icmp ult <2 x i8> %C, %v
+  %s = select <2 x i1> %cmp, <2 x i8> %v, <2 x i8> %y
+  %r = icmp eq <2 x i8> %s, zeroinitializer
+  ret <2 x i1> %r
+}
+
+define <2 x i1> @select_v_uge_nz(<2 x i8> %v, <2 x i8> %yy) {
+; CHECK-LABEL: @select_v_uge_nz(
+; CHECK-NEXT:    [[Y:%.*]] = or <2 x i8> [[YY:%.*]], <i8 1, i8 1>
+; CHECK-NEXT:    [[CMP:%.*]] = icmp uge <2 x i8> [[V:%.*]], <i8 1, i8 1>
+; CHECK-NEXT:    [[S:%.*]] = select <2 x i1> [[CMP]], <2 x i8> [[V]], <2 x i8> [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq <2 x i8> [[S]], zeroinitializer
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %y = or <2 x i8> %yy, <i8 1, i8 1>
+  %cmp = icmp uge <2 x i8> %v, <i8 1, i8 1>
+  %s = select <2 x i1> %cmp, <2 x i8> %v, <2 x i8> %y
+  %r = icmp eq <2 x i8> %s, zeroinitializer
+  ret <2 x i1> %r
+}
+
+define i1 @inv_select_v_ule(i8 %v, i8 %y) {
+; CHECK-LABEL: @inv_select_v_ule(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ule i8 [[V:%.*]], 4
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[Y]], i8 [[V]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp ule i8 %v, 4
+  %s = select i1 %cmp, i8 %y, i8 %v
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_sgt_nonneg(i8 %v, i8 %y) {
+; CHECK-LABEL: @select_v_sgt_nonneg(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[V:%.*]], 0
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp sgt i8 %v, 0
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_sgt_fail(i8 %v, i8 %y) {
+; CHECK-LABEL: @select_v_sgt_fail(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[V:%.*]], -1
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp sgt i8 %v, -1
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @inv_select_v_sgt_neg(i8 %v, i8 %y) {
+; CHECK-LABEL: @inv_select_v_sgt_neg(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[V:%.*]], -1
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[Y]], i8 [[V]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp sgt i8 %v, -1
+  %s = select i1 %cmp, i8 %y, i8 %v
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @inv_select_v_sgt_nonneg_nz(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @inv_select_v_sgt_nonneg_nz(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 99, [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[Y]], i8 [[V]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp sgt i8 99, %v
+  %s = select i1 %cmp, i8 %y, i8 %v
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_slt_nonneg(i8 %v, i8 %y) {
+; CHECK-LABEL: @select_v_slt_nonneg(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i8 0, [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp slt i8 0, %v
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_slt_nonneg_fail(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @select_v_slt_nonneg_fail(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i8 -1, [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp slt i8 -1, %v
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_slt_neg(i8 %v, i8 %y) {
+; CHECK-LABEL: @select_v_slt_neg(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i8 [[V:%.*]], -1
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp slt i8 %v, -1
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_sge_nonneg_nz(i8 %v, i8 %y) {
+; CHECK-LABEL: @select_v_sge_nonneg_nz(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i8 [[V:%.*]], 1
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp sge i8 %v, 1
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_sge_neg(i8 %v, i8 %y) {
+; CHECK-LABEL: @select_v_sge_neg(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i8 -3, [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp sge i8 -3, %v
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @inv_select_v_sge_z(i8 %v, i8 %y) {
+; CHECK-LABEL: @inv_select_v_sge_z(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i8 [[V:%.*]], 0
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[Y]], i8 [[V]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp sge i8 %v, 0
+  %s = select i1 %cmp, i8 %y, i8 %v
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @inv_select_v_sge_fail(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @inv_select_v_sge_fail(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i8 [[V:%.*]], -44
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[Y]], i8 [[V]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp sge i8 %v, -44
+  %s = select i1 %cmp, i8 %y, i8 %v
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_sle_neg(i8 %v, i8 %y) {
+; CHECK-LABEL: @select_v_sle_neg(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sle i8 [[V:%.*]], -1
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp sle i8 %v, -1
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_sle_nonneg_nz(i8 %v, i8 %y) {
+; CHECK-LABEL: @select_v_sle_nonneg_nz(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sle i8 1, [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp sle i8 1, %v
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_sle_fail(i8 %v, i8 %y) {
+; CHECK-LABEL: @select_v_sle_fail(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sle i8 0, [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp sle i8 0, %v
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @inv_select_v_sle_nonneg(i8 %v, i8 %y) {
+; CHECK-LABEL: @inv_select_v_sle_nonneg(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sle i8 [[V:%.*]], 0
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[Y]], i8 [[V]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp sle i8 %v, 0
+  %s = select i1 %cmp, i8 %y, i8 %v
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}

diff --git a/llvm/test/Analysis/ValueTracking/select-known-non-zero.ll b/llvm/test/Analysis/ValueTracking/select-known-non-zero.ll
new file mode 100644 (file)
index 0000000..bcd830e
--- /dev/null
+++ b/llvm/test/Analysis/ValueTracking/select-known-non-zero.ll
@@ -0,0 +1,394 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes=instsimplify -S | FileCheck %s
+
+declare void @llvm.assume(i1)
+define i1 @select_v_ne_fail(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @select_v_ne_fail(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i8 [[V:%.*]], [[C:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp ne i8 %v, %C
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_eq_nz(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @select_v_eq_nz(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[PCOND0:%.*]] = icmp ne i8 [[C:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[PCOND0]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[C]], [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %pcond0 = icmp ne i8 %C, 0
+  call void @llvm.assume(i1 %pcond0)
+  %cmp = icmp eq i8 %C, %v
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @inv_select_v_ugt_nz(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @inv_select_v_ugt_nz(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[PCOND0:%.*]] = icmp ne i8 [[C:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[PCOND0]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i8 [[C]], [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[Y]], i8 [[V]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %pcond0 = icmp ne i8 %C, 0
+  call void @llvm.assume(i1 %pcond0)
+  %cmp = icmp ugt i8 %C, %v
+  %s = select i1 %cmp, i8 %y, i8 %v
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @inv_select_v_ugt_fail(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @inv_select_v_ugt_fail(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[PCOND0:%.*]] = icmp sge i8 [[C:%.*]], -8
+; CHECK-NEXT:    call void @llvm.assume(i1 [[PCOND0]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ugt i8 [[C]], [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[Y]], i8 [[V]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %pcond0 = icmp sge i8 %C, -8
+  call void @llvm.assume(i1 %pcond0)
+  %cmp = icmp ugt i8 %C, %v
+  %s = select i1 %cmp, i8 %y, i8 %v
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_uge_nz(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @select_v_uge_nz(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[PCOND0:%.*]] = icmp ne i8 [[C:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[PCOND0]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp uge i8 [[V:%.*]], [[C]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %pcond0 = icmp ne i8 %C, 0
+  call void @llvm.assume(i1 %pcond0)
+  %cmp = icmp uge i8 %v, %C
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_sgt_nonneg(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @select_v_sgt_nonneg(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[PCOND0:%.*]] = icmp sge i8 [[C:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[PCOND0]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[V:%.*]], [[C]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %pcond0 = icmp sge i8 %C, 0
+  call void @llvm.assume(i1 %pcond0)
+  %cmp = icmp sgt i8 %v, %C
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_sgt_fail(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @select_v_sgt_fail(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[PCOND0:%.*]] = icmp sge i8 [[C:%.*]], -4
+; CHECK-NEXT:    call void @llvm.assume(i1 [[PCOND0]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[V:%.*]], [[C]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %pcond0 = icmp sge i8 %C, -4
+  call void @llvm.assume(i1 %pcond0)
+  %cmp = icmp sgt i8 %v, %C
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @inv_select_v_sgt_neg(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @inv_select_v_sgt_neg(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[PCOND0:%.*]] = icmp slt i8 [[C:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[PCOND0]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[V:%.*]], [[C]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[Y]], i8 [[V]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %pcond0 = icmp slt i8 %C, 0
+  call void @llvm.assume(i1 %pcond0)
+  %cmp = icmp sgt i8 %v, %C
+  %s = select i1 %cmp, i8 %y, i8 %v
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @inv_select_v_sgt_nonneg_nz(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @inv_select_v_sgt_nonneg_nz(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[PCOND0:%.*]] = icmp sgt i8 [[C:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[PCOND0]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sgt i8 [[C]], [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[Y]], i8 [[V]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %pcond0 = icmp sgt i8 %C, 0
+  call void @llvm.assume(i1 %pcond0)
+  %cmp = icmp sgt i8 %C, %v
+  %s = select i1 %cmp, i8 %y, i8 %v
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_slt_nonneg(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @select_v_slt_nonneg(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[PCOND0:%.*]] = icmp sge i8 [[C:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[PCOND0]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i8 [[C]], [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %pcond0 = icmp sge i8 %C, 0
+  call void @llvm.assume(i1 %pcond0)
+  %cmp = icmp slt i8 %C, %v
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_slt_nonneg_fail(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @select_v_slt_nonneg_fail(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[PCOND0:%.*]] = icmp sge i8 [[C:%.*]], -1
+; CHECK-NEXT:    call void @llvm.assume(i1 [[PCOND0]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i8 [[C]], [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %pcond0 = icmp sge i8 %C, -1
+  call void @llvm.assume(i1 %pcond0)
+  %cmp = icmp slt i8 %C, %v
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_slt_neg(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @select_v_slt_neg(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[PCOND0:%.*]] = icmp slt i8 [[C:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[PCOND0]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i8 [[V:%.*]], [[C]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %pcond0 = icmp slt i8 %C, 0
+  call void @llvm.assume(i1 %pcond0)
+  %cmp = icmp slt i8 %v, %C
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_sge_nonneg_nz(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @select_v_sge_nonneg_nz(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[PCOND0:%.*]] = icmp sgt i8 [[C:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[PCOND0]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i8 [[V:%.*]], [[C]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %pcond0 = icmp sgt i8 %C, 0
+  call void @llvm.assume(i1 %pcond0)
+  %cmp = icmp sge i8 %v, %C
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_sge_neg(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @select_v_sge_neg(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[PCOND0:%.*]] = icmp slt i8 [[C:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[PCOND0]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i8 [[C]], [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %pcond0 = icmp slt i8 %C, 0
+  call void @llvm.assume(i1 %pcond0)
+  %cmp = icmp sge i8 %C, %v
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @inv_select_v_sge_fail(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @inv_select_v_sge_fail(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sge i8 [[V:%.*]], [[C:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[Y]], i8 [[V]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %cmp = icmp sge i8 %v, %C
+  %s = select i1 %cmp, i8 %y, i8 %v
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_sle_neg(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @select_v_sle_neg(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[PCOND0:%.*]] = icmp slt i8 [[C:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[PCOND0]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sle i8 [[V:%.*]], [[C]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %pcond0 = icmp slt i8 %C, 0
+  call void @llvm.assume(i1 %pcond0)
+  %cmp = icmp sle i8 %v, %C
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_sle_nonneg_nz(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @select_v_sle_nonneg_nz(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[PCOND0:%.*]] = icmp sgt i8 [[C:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[PCOND0]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sle i8 [[C]], [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %pcond0 = icmp sgt i8 %C, 0
+  call void @llvm.assume(i1 %pcond0)
+  %cmp = icmp sle i8 %C, %v
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @select_v_sle_fail(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @select_v_sle_fail(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[PCOND0:%.*]] = icmp sge i8 [[C:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[PCOND0]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sle i8 [[C]], [[V:%.*]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[V]], i8 [[Y]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %pcond0 = icmp sge i8 %C, 0
+  call void @llvm.assume(i1 %pcond0)
+  %cmp = icmp sle i8 %C, %v
+  %s = select i1 %cmp, i8 %v, i8 %y
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}
+
+define i1 @inv_select_v_sle_nonneg(i8 %v, i8 %C, i8 %y) {
+; CHECK-LABEL: @inv_select_v_sle_nonneg(
+; CHECK-NEXT:    [[YNZ:%.*]] = icmp ne i8 [[Y:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[YNZ]])
+; CHECK-NEXT:    [[PCOND0:%.*]] = icmp sge i8 [[C:%.*]], 0
+; CHECK-NEXT:    call void @llvm.assume(i1 [[PCOND0]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp sle i8 [[V:%.*]], [[C]]
+; CHECK-NEXT:    [[S:%.*]] = select i1 [[CMP]], i8 [[Y]], i8 [[V]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[S]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %ynz = icmp ne i8 %y, 0
+  call void @llvm.assume(i1 %ynz)
+  %pcond0 = icmp sge i8 %C, 0
+  call void @llvm.assume(i1 %pcond0)
+  %cmp = icmp sle i8 %v, %C
+  %s = select i1 %cmp, i8 %y, i8 %v
+  %r = icmp eq i8 %s, 0
+  ret i1 %r
+}