From fd8280fc36816232eb498f00a08d0235d885e78f Mon Sep 17 00:00:00 2001
From: Roman Lebedev <lebedev.ri@gmail.com>
Date: Thu, 5 Sep 2019 19:13:15 +0000
Subject: [PATCH] [NFC][InstCombine] Overhaul 'unsigned add overflow' tests,
 ensure that all 3 patterns have full test coverage

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@371108 91177308-0d34-0410-b5e6-96231b3b80d8
---
 ...gned-add-lack-of-overflow-check-via-add.ll | 236 ++++++++++++++++++
 ...gned-add-lack-of-overflow-check-via-xor.ll | 189 ++++++++++++++
 .../unsigned-add-lack-of-overflow-check.ll    |   8 +-
 .../unsigned-add-overflow-check-via-add.ll    | 232 +++++++++++++++++
 .../unsigned-add-overflow-check-via-xor.ll    | 189 ++++++++++++++
 .../unsigned-add-overflow-check.ll            |   8 +-
 6 files changed, 854 insertions(+), 8 deletions(-)
 create mode 100644 test/Transforms/InstCombine/unsigned-add-lack-of-overflow-check-via-add.ll
 create mode 100644 test/Transforms/InstCombine/unsigned-add-lack-of-overflow-check-via-xor.ll
 create mode 100644 test/Transforms/InstCombine/unsigned-add-overflow-check-via-add.ll
 create mode 100644 test/Transforms/InstCombine/unsigned-add-overflow-check-via-xor.ll

diff --git a/test/Transforms/InstCombine/unsigned-add-lack-of-overflow-check-via-add.ll b/test/Transforms/InstCombine/unsigned-add-lack-of-overflow-check-via-add.ll
new file mode 100644
index 00000000000..b39f2bb8bec
--- /dev/null
+++ b/test/Transforms/InstCombine/unsigned-add-lack-of-overflow-check-via-add.ll
@@ -0,0 +1,236 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt %s -instcombine -S | FileCheck %s
+
+; Should fold
+;   (%x + %y) u>= %x
+; or
+;   (%x + %y) u>= %y
+; to
+;   @llvm.uadd.with.overflow(%x, %y) + extractvalue + not
+;
+; All tests here have extra uses, to ensure that the pattern isn't perturbed.
+
+declare void @use8(i8)
+declare void @use2x8(<2 x i8>)
+
+define i1 @t0_basic(i8 %x, i8 %y) {
+; CHECK-LABEL: @t0_basic(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp uge i8 [[T0]], [[Y]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp uge i8 %t0, %y
+  ret i1 %r
+}
+
+define <2 x i1> @t1_vec(<2 x i8> %x, <2 x i8> %y) {
+; CHECK-LABEL: @t1_vec(
+; CHECK-NEXT:    [[T0:%.*]] = add <2 x i8> [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use2x8(<2 x i8> [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp uge <2 x i8> [[T0]], [[Y]]
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %t0 = add <2 x i8> %x, %y
+  call void @use2x8(<2 x i8> %t0)
+  %r = icmp uge <2 x i8> %t0, %y
+  ret <2 x i1> %r
+}
+
+; Commutativity
+
+define i1 @t2_symmetry(i8 %x, i8 %y) {
+; CHECK-LABEL: @t2_symmetry(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp uge i8 [[T0]], [[X]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp uge i8 %t0, %x ; can check against either of `add` arguments
+  ret i1 %r
+}
+
+declare i8 @gen8()
+
+define i1 @t3_commutative(i8 %x) {
+; CHECK-LABEL: @t3_commutative(
+; CHECK-NEXT:    [[Y:%.*]] = call i8 @gen8()
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[Y]], [[X:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp uge i8 [[T0]], [[Y]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %y = call i8 @gen8()
+  %t0 = add i8 %y, %x ; swapped
+  call void @use8(i8 %t0)
+  %r = icmp uge i8 %t0, %y
+  ret i1 %r
+}
+
+define i1 @t4_commutative() {
+; CHECK-LABEL: @t4_commutative(
+; CHECK-NEXT:    [[X:%.*]] = call i8 @gen8()
+; CHECK-NEXT:    [[Y:%.*]] = call i8 @gen8()
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X]], [[Y]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ule i8 [[Y]], [[T0]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %x = call i8 @gen8()
+  %y = call i8 @gen8()
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp ule i8 %y, %t0 ; swapped
+  ret i1 %r
+}
+
+define i1 @t5_commutative(i8 %x) {
+; CHECK-LABEL: @t5_commutative(
+; CHECK-NEXT:    [[Y:%.*]] = call i8 @gen8()
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[Y]], [[X:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ule i8 [[Y]], [[T0]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %y = call i8 @gen8()
+  %t0 = add i8 %y, %x ; swapped
+  call void @use8(i8 %t0)
+  %r = icmp ule i8 %y, %t0 ; swapped
+  ret i1 %r
+}
+
+; Extra-use tests
+
+define i1 @t6_no_extrause(i8 %x, i8 %y) {
+; CHECK-LABEL: @t6_no_extrause(
+; CHECK-NEXT:    [[TMP1:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    [[R:%.*]] = icmp uge i8 [[TMP1]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  %r = icmp uge i8 %t0, %y
+  ret i1 %r
+}
+
+; Negative tests
+
+define i1 @n7_different_y(i8 %x, i8 %y0, i8 %y1) {
+; CHECK-LABEL: @n7_different_y(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y0:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp uge i8 [[T0]], [[Y1:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y0
+  call void @use8(i8 %t0)
+  %r = icmp uge i8 %t0, %y1
+  ret i1 %r
+}
+
+define i1 @n8_wrong_pred0(i8 %x, i8 %y) {
+; CHECK-LABEL: @n8_wrong_pred0(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ule i8 [[T0]], [[Y]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp ule i8 %t0, %y
+  ret i1 %r
+}
+
+define i1 @n9_wrong_pred1(i8 %x, i8 %y) {
+; CHECK-LABEL: @n9_wrong_pred1(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ugt i8 [[T0]], [[Y]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp ugt i8 %t0, %y
+  ret i1 %r
+}
+
+define i1 @n10_wrong_pred2(i8 %x, i8 %y) {
+; CHECK-LABEL: @n10_wrong_pred2(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[X]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp eq i8 %t0, %y
+  ret i1 %r
+}
+
+define i1 @n11_wrong_pred3(i8 %x, i8 %y) {
+; CHECK-LABEL: @n11_wrong_pred3(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ne i8 [[X]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp ne i8 %t0, %y
+  ret i1 %r
+}
+
+define i1 @n12_wrong_pred4(i8 %x, i8 %y) {
+; CHECK-LABEL: @n12_wrong_pred4(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp slt i8 [[T0]], [[Y]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp slt i8 %t0, %y
+  ret i1 %r
+}
+
+define i1 @n13_wrong_pred5(i8 %x, i8 %y) {
+; CHECK-LABEL: @n13_wrong_pred5(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp sle i8 [[T0]], [[Y]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp sle i8 %t0, %y
+  ret i1 %r
+}
+
+define i1 @n14_wrong_pred6(i8 %x, i8 %y) {
+; CHECK-LABEL: @n14_wrong_pred6(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp sgt i8 [[T0]], [[Y]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp sgt i8 %t0, %y
+  ret i1 %r
+}
+
+define i1 @n15_wrong_pred7(i8 %x, i8 %y) {
+; CHECK-LABEL: @n15_wrong_pred7(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp sge i8 [[T0]], [[Y]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp sge i8 %t0, %y
+  ret i1 %r
+}
diff --git a/test/Transforms/InstCombine/unsigned-add-lack-of-overflow-check-via-xor.ll b/test/Transforms/InstCombine/unsigned-add-lack-of-overflow-check-via-xor.ll
new file mode 100644
index 00000000000..f48bd6c9abc
--- /dev/null
+++ b/test/Transforms/InstCombine/unsigned-add-lack-of-overflow-check-via-xor.ll
@@ -0,0 +1,189 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt %s -instcombine -S | FileCheck %s
+
+; Should fold
+;   (%y ^ -1) u>= %x
+; to
+;   @llvm.uadd.with.overflow(%x, %y) + extractvalue + not
+;
+; All tests here have extra uses, to ensure that the pattern isn't perturbed.
+
+declare void @use8(i8)
+declare void @use2x8(<2 x i8>)
+
+define i1 @t0_basic(i8 %x, i8 %y) {
+; CHECK-LABEL: @t0_basic(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp uge i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp uge i8 %t0, %x
+  ret i1 %r
+}
+
+define <2 x i1> @t1_vec(<2 x i8> %x, <2 x i8> %y) {
+; CHECK-LABEL: @t1_vec(
+; CHECK-NEXT:    [[T0:%.*]] = xor <2 x i8> [[Y:%.*]], <i8 -1, i8 -1>
+; CHECK-NEXT:    call void @use2x8(<2 x i8> [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp uge <2 x i8> [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %t0 = xor <2 x i8> %y, <i8 -1, i8 -1>
+  call void @use2x8(<2 x i8> %t0)
+  %r = icmp uge <2 x i8> %t0, %x
+  ret <2 x i1> %r
+}
+
+; Commutativity
+
+declare i8 @gen8()
+
+define i1 @t2_commutative(i8 %y) {
+; CHECK-LABEL: @t2_commutative(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[X:%.*]] = call i8 @gen8()
+; CHECK-NEXT:    [[R:%.*]] = icmp ule i8 [[X]], [[T0]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %x = call i8 @gen8()
+  %r = icmp ule i8 %x, %t0 ; swapped
+  ret i1 %r
+}
+
+; Extra-use tests
+
+define i1 @t3_no_extrause(i8 %x, i8 %y) {
+; CHECK-LABEL: @t3_no_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    [[R:%.*]] = icmp uge i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  %r = icmp uge i8 %t0, %x
+  ret i1 %r
+}
+
+; Negative tests
+
+define i1 @n4_wrong_pred0(i8 %x, i8 %y) {
+; CHECK-LABEL: @n4_wrong_pred0(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ule i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp ule i8 %t0, %x
+  ret i1 %r
+}
+
+define i1 @n5_wrong_pred1(i8 %x, i8 %y) {
+; CHECK-LABEL: @n5_wrong_pred1(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ugt i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp ugt i8 %t0, %x
+  ret i1 %r
+}
+
+define i1 @n6_wrong_pred2(i8 %x, i8 %y) {
+; CHECK-LABEL: @n6_wrong_pred2(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp eq i8 %t0, %x
+  ret i1 %r
+}
+
+define i1 @n7_wrong_pred3(i8 %x, i8 %y) {
+; CHECK-LABEL: @n7_wrong_pred3(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ne i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp ne i8 %t0, %x
+  ret i1 %r
+}
+
+define i1 @n8_wrong_pred4(i8 %x, i8 %y) {
+; CHECK-LABEL: @n8_wrong_pred4(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp slt i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp slt i8 %t0, %x
+  ret i1 %r
+}
+
+define i1 @n9_wrong_pred5(i8 %x, i8 %y) {
+; CHECK-LABEL: @n9_wrong_pred5(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp sle i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp sle i8 %t0, %x
+  ret i1 %r
+}
+
+define i1 @n10_wrong_pred6(i8 %x, i8 %y) {
+; CHECK-LABEL: @n10_wrong_pred6(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp sgt i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp sgt i8 %t0, %x
+  ret i1 %r
+}
+
+define i1 @n11_wrong_pred7(i8 %x, i8 %y) {
+; CHECK-LABEL: @n11_wrong_pred7(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp sge i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp sge i8 %t0, %x
+  ret i1 %r
+}
+
+define <2 x i1> @n12_vec_nonsplat(<2 x i8> %x, <2 x i8> %y) {
+; CHECK-LABEL: @n12_vec_nonsplat(
+; CHECK-NEXT:    [[T0:%.*]] = xor <2 x i8> [[Y:%.*]], <i8 -1, i8 -2>
+; CHECK-NEXT:    call void @use2x8(<2 x i8> [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp uge <2 x i8> [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %t0 = xor <2 x i8> %y, <i8 -1, i8 -2> ; must be -1.
+  call void @use2x8(<2 x i8> %t0)
+  %r = icmp uge <2 x i8> %t0, %x
+  ret <2 x i1> %r
+}
diff --git a/test/Transforms/InstCombine/unsigned-add-lack-of-overflow-check.ll b/test/Transforms/InstCombine/unsigned-add-lack-of-overflow-check.ll
index 30e7d541615..29c195f3a6c 100644
--- a/test/Transforms/InstCombine/unsigned-add-lack-of-overflow-check.ll
+++ b/test/Transforms/InstCombine/unsigned-add-lack-of-overflow-check.ll
@@ -1,12 +1,12 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt %s -instcombine -S | FileCheck %s
 
-; Fold
+; Should fold
 ;   (%x + %y) u>= %x
 ; or
 ;   (%x + %y) u>= %y
 ; to
-;   @llvm.add.with.overflow(%x, %y) + extractvalue + not
+;   @llvm.uadd.with.overflow(%x, %y) + extractvalue + not
 
 define i1 @t0_basic(i8 %x, i8 %y) {
 ; CHECK-LABEL: @t0_basic(
@@ -86,8 +86,8 @@ define i1 @t5_commutative(i8 %x) {
 
 declare void @use8(i8)
 
-define i1 @t6_extrause0(i8 %x, i8 %y) {
-; CHECK-LABEL: @t6_extrause0(
+define i1 @t6_extrause(i8 %x, i8 %y) {
+; CHECK-LABEL: @t6_extrause(
 ; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
 ; CHECK-NEXT:    call void @use8(i8 [[T0]])
 ; CHECK-NEXT:    [[R:%.*]] = icmp uge i8 [[T0]], [[Y]]
diff --git a/test/Transforms/InstCombine/unsigned-add-overflow-check-via-add.ll b/test/Transforms/InstCombine/unsigned-add-overflow-check-via-add.ll
new file mode 100644
index 00000000000..a614142ef45
--- /dev/null
+++ b/test/Transforms/InstCombine/unsigned-add-overflow-check-via-add.ll
@@ -0,0 +1,232 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt %s -instcombine -S | FileCheck %s
+
+; Should fold
+;   (%x + %y) u< %x
+; or
+;   (%x + %y) u< %y
+; to
+;   @llvm.uadd.with.overflow(%x, %y) + extractvalue
+;
+; All tests here have extra uses, to ensure that the pattern isn't perturbed.
+
+declare void @use8(i8)
+declare void @use2x8(<2 x i8>)
+
+define i1 @t0_basic(i8 %x, i8 %y) {
+; CHECK-LABEL: @t0_basic(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ult i8 [[T0]], [[Y]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp ult i8 %t0, %y
+  ret i1 %r
+}
+
+define <2 x i1> @t1_vec(<2 x i8> %x, <2 x i8> %y) {
+; CHECK-LABEL: @t1_vec(
+; CHECK-NEXT:    [[T0:%.*]] = add <2 x i8> [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use2x8(<2 x i8> [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ult <2 x i8> [[T0]], [[Y]]
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %t0 = add <2 x i8> %x, %y
+  call void @use2x8(<2 x i8> %t0)
+  %r = icmp ult <2 x i8> %t0, %y
+  ret <2 x i1> %r
+}
+
+; Commutativity
+
+define i1 @t2_symmetry(i8 %x, i8 %y) {
+; CHECK-LABEL: @t2_symmetry(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ult i8 [[T0]], [[X]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp ult i8 %t0, %x ; can check against either of `add` arguments
+  ret i1 %r
+}
+
+declare i8 @gen8()
+
+define i1 @t3_commutative(i8 %x) {
+; CHECK-LABEL: @t3_commutative(
+; CHECK-NEXT:    [[Y:%.*]] = call i8 @gen8()
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[Y]], [[X:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ult i8 [[T0]], [[Y]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %y = call i8 @gen8()
+  %t0 = add i8 %y, %x ; swapped
+  call void @use8(i8 %t0)
+  %r = icmp ult i8 %t0, %y
+  ret i1 %r
+}
+
+define i1 @t4_commutative(i8 %x, i8 %y) {
+; CHECK-LABEL: @t4_commutative(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ult i8 [[T0]], [[Y]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp ugt i8 %y, %t0 ; swapped
+  ret i1 %r
+}
+
+define i1 @t5_commutative(i8 %x) {
+; CHECK-LABEL: @t5_commutative(
+; CHECK-NEXT:    [[Y:%.*]] = call i8 @gen8()
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[Y]], [[X:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ugt i8 [[Y]], [[T0]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %y = call i8 @gen8()
+  %t0 = add i8 %y, %x ; swapped
+  call void @use8(i8 %t0)
+  %r = icmp ugt i8 %y, %t0 ; swapped
+  ret i1 %r
+}
+
+; Extra-use tests
+
+define i1 @t6_no_extrause(i8 %x, i8 %y) {
+; CHECK-LABEL: @t6_no_extrause(
+; CHECK-NEXT:    [[TMP1:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    [[R:%.*]] = icmp ult i8 [[TMP1]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  %r = icmp ult i8 %t0, %y
+  ret i1 %r
+}
+
+; Negative tests
+
+define i1 @n7_different_y(i8 %x, i8 %y0, i8 %y1) {
+; CHECK-LABEL: @n7_different_y(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y0:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ult i8 [[T0]], [[Y1:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y0
+  call void @use8(i8 %t0)
+  %r = icmp ult i8 %t0, %y1
+  ret i1 %r
+}
+
+define i1 @n8_wrong_pred0(i8 %x, i8 %y) {
+; CHECK-LABEL: @n8_wrong_pred0(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ule i8 [[T0]], [[Y]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp ule i8 %t0, %y
+  ret i1 %r
+}
+
+define i1 @n9_wrong_pred1(i8 %x, i8 %y) {
+; CHECK-LABEL: @n9_wrong_pred1(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ugt i8 [[T0]], [[Y]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp ugt i8 %t0, %y
+  ret i1 %r
+}
+
+define i1 @n10_wrong_pred2(i8 %x, i8 %y) {
+; CHECK-LABEL: @n10_wrong_pred2(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[X]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp eq i8 %t0, %y
+  ret i1 %r
+}
+
+define i1 @n11_wrong_pred3(i8 %x, i8 %y) {
+; CHECK-LABEL: @n11_wrong_pred3(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ne i8 [[X]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp ne i8 %t0, %y
+  ret i1 %r
+}
+
+define i1 @n12_wrong_pred4(i8 %x, i8 %y) {
+; CHECK-LABEL: @n12_wrong_pred4(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp slt i8 [[T0]], [[Y]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp slt i8 %t0, %y
+  ret i1 %r
+}
+
+define i1 @n13_wrong_pred5(i8 %x, i8 %y) {
+; CHECK-LABEL: @n13_wrong_pred5(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp sle i8 [[T0]], [[Y]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp sle i8 %t0, %y
+  ret i1 %r
+}
+
+define i1 @n14_wrong_pred6(i8 %x, i8 %y) {
+; CHECK-LABEL: @n14_wrong_pred6(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp sgt i8 [[T0]], [[Y]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp sgt i8 %t0, %y
+  ret i1 %r
+}
+
+define i1 @n15_wrong_pred7(i8 %x, i8 %y) {
+; CHECK-LABEL: @n15_wrong_pred7(
+; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp sge i8 [[T0]], [[Y]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = add i8 %x, %y
+  call void @use8(i8 %t0)
+  %r = icmp sge i8 %t0, %y
+  ret i1 %r
+}
diff --git a/test/Transforms/InstCombine/unsigned-add-overflow-check-via-xor.ll b/test/Transforms/InstCombine/unsigned-add-overflow-check-via-xor.ll
new file mode 100644
index 00000000000..e8fa5c84d14
--- /dev/null
+++ b/test/Transforms/InstCombine/unsigned-add-overflow-check-via-xor.ll
@@ -0,0 +1,189 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt %s -instcombine -S | FileCheck %s
+
+; Should fold
+;   (%y ^ -1) u< %x
+; to
+;   @llvm.uadd.with.overflow(%x, %y) + extractvalue + not
+;
+; All tests here have extra uses, to ensure that the pattern isn't perturbed.
+
+declare void @use8(i8)
+declare void @use2x8(<2 x i8>)
+
+define i1 @t0_basic(i8 %x, i8 %y) {
+; CHECK-LABEL: @t0_basic(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ult i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp ult i8 %t0, %x
+  ret i1 %r
+}
+
+define <2 x i1> @t1_vec(<2 x i8> %x, <2 x i8> %y) {
+; CHECK-LABEL: @t1_vec(
+; CHECK-NEXT:    [[T0:%.*]] = xor <2 x i8> [[Y:%.*]], <i8 -1, i8 -1>
+; CHECK-NEXT:    call void @use2x8(<2 x i8> [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ult <2 x i8> [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %t0 = xor <2 x i8> %y, <i8 -1, i8 -1>
+  call void @use2x8(<2 x i8> %t0)
+  %r = icmp ult <2 x i8> %t0, %x
+  ret <2 x i1> %r
+}
+
+; Commutativity
+
+declare i8 @gen8()
+
+define i1 @t2_commutative(i8 %y) {
+; CHECK-LABEL: @t2_commutative(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[X:%.*]] = call i8 @gen8()
+; CHECK-NEXT:    [[R:%.*]] = icmp ule i8 [[X]], [[T0]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %x = call i8 @gen8()
+  %r = icmp ule i8 %x, %t0 ; swapped
+  ret i1 %r
+}
+
+; Extra-use tests
+
+define i1 @t3_no_extrause(i8 %x, i8 %y) {
+; CHECK-LABEL: @t3_no_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    [[R:%.*]] = icmp ult i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  %r = icmp ult i8 %t0, %x
+  ret i1 %r
+}
+
+; Negative tests
+
+define i1 @n4_wrong_pred0(i8 %x, i8 %y) {
+; CHECK-LABEL: @n4_wrong_pred0(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ule i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp ule i8 %t0, %x
+  ret i1 %r
+}
+
+define i1 @n5_wrong_pred1(i8 %x, i8 %y) {
+; CHECK-LABEL: @n5_wrong_pred1(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ugt i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp ugt i8 %t0, %x
+  ret i1 %r
+}
+
+define i1 @n6_wrong_pred2(i8 %x, i8 %y) {
+; CHECK-LABEL: @n6_wrong_pred2(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp eq i8 %t0, %x
+  ret i1 %r
+}
+
+define i1 @n7_wrong_pred3(i8 %x, i8 %y) {
+; CHECK-LABEL: @n7_wrong_pred3(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ne i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp ne i8 %t0, %x
+  ret i1 %r
+}
+
+define i1 @n8_wrong_pred4(i8 %x, i8 %y) {
+; CHECK-LABEL: @n8_wrong_pred4(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp slt i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp slt i8 %t0, %x
+  ret i1 %r
+}
+
+define i1 @n9_wrong_pred5(i8 %x, i8 %y) {
+; CHECK-LABEL: @n9_wrong_pred5(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp sle i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp sle i8 %t0, %x
+  ret i1 %r
+}
+
+define i1 @n10_wrong_pred6(i8 %x, i8 %y) {
+; CHECK-LABEL: @n10_wrong_pred6(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp sgt i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp sgt i8 %t0, %x
+  ret i1 %r
+}
+
+define i1 @n11_wrong_pred7(i8 %x, i8 %y) {
+; CHECK-LABEL: @n11_wrong_pred7(
+; CHECK-NEXT:    [[T0:%.*]] = xor i8 [[Y:%.*]], -1
+; CHECK-NEXT:    call void @use8(i8 [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp sge i8 [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %t0 = xor i8 %y, -1
+  call void @use8(i8 %t0)
+  %r = icmp sge i8 %t0, %x
+  ret i1 %r
+}
+
+define <2 x i1> @n12_vec_nonsplat(<2 x i8> %x, <2 x i8> %y) {
+; CHECK-LABEL: @n12_vec_nonsplat(
+; CHECK-NEXT:    [[T0:%.*]] = xor <2 x i8> [[Y:%.*]], <i8 -1, i8 -2>
+; CHECK-NEXT:    call void @use2x8(<2 x i8> [[T0]])
+; CHECK-NEXT:    [[R:%.*]] = icmp ult <2 x i8> [[T0]], [[X:%.*]]
+; CHECK-NEXT:    ret <2 x i1> [[R]]
+;
+  %t0 = xor <2 x i8> %y, <i8 -1, i8 -2> ; must be -1.
+  call void @use2x8(<2 x i8> %t0)
+  %r = icmp ult <2 x i8> %t0, %x
+  ret <2 x i1> %r
+}
diff --git a/test/Transforms/InstCombine/unsigned-add-overflow-check.ll b/test/Transforms/InstCombine/unsigned-add-overflow-check.ll
index cbc7ee24890..d1ab9ae41d6 100644
--- a/test/Transforms/InstCombine/unsigned-add-overflow-check.ll
+++ b/test/Transforms/InstCombine/unsigned-add-overflow-check.ll
@@ -1,12 +1,12 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt %s -instcombine -S | FileCheck %s
 
-; Fold
+; Should fold
 ;   (%x + %y) u< %x
 ; or
 ;   (%x + %y) u< %y
 ; to
-;   @llvm.add.with.overflow(%x, %y) + extractvalue
+;   @llvm.uadd.with.overflow(%x, %y) + extractvalue
 
 define i1 @t0_basic(i8 %x, i8 %y) {
 ; CHECK-LABEL: @t0_basic(
@@ -86,8 +86,8 @@ define i1 @t5_commutative(i8 %x) {
 
 declare void @use8(i8)
 
-define i1 @t6_extrause0(i8 %x, i8 %y) {
-; CHECK-LABEL: @t6_extrause0(
+define i1 @t6_extrause(i8 %x, i8 %y) {
+; CHECK-LABEL: @t6_extrause(
 ; CHECK-NEXT:    [[T0:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
 ; CHECK-NEXT:    call void @use8(i8 [[T0]])
 ; CHECK-NEXT:    [[R:%.*]] = icmp ult i8 [[T0]], [[Y]]
-- 
2.40.0