From d1d915b8da91e3e527706c838e2cb4b338336e7a Mon Sep 17 00:00:00 2001
From: Roman Lebedev <lebedev.ri@gmail.com>
Date: Fri, 31 May 2019 08:24:07 +0000
Subject: [PATCH] [NFC][InstCombine] Copy add/sub constant-folding tests from
 codegen

Last three patterns are missed.

llvm-svn: 362209
---
 .../InstCombine/addsub-constant-folding.ll    | 536 ++++++++++++++++++
 1 file changed, 536 insertions(+)
 create mode 100644 llvm/test/Transforms/InstCombine/addsub-constant-folding.ll

diff --git a/llvm/test/Transforms/InstCombine/addsub-constant-folding.ll b/llvm/test/Transforms/InstCombine/addsub-constant-folding.ll
new file mode 100644
index 000000000000..fc98f249fc52
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/addsub-constant-folding.ll
@@ -0,0 +1,536 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+declare void @use(i32 %arg)
+declare void @vec_use(<4 x i32> %arg)
+
+; (x+c1)+c2
+
+define i32 @add_const_add_const(i32 %arg) {
+; CHECK-LABEL: @add_const_add_const(
+; CHECK-NEXT:    [[T1:%.*]] = add i32 [[ARG:%.*]], 10
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = add i32 %arg, 8
+  %t1 = add i32 %t0, 2
+  ret i32 %t1
+}
+
+define i32 @add_const_add_const_extrause(i32 %arg) {
+; CHECK-LABEL: @add_const_add_const_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = add i32 [[ARG:%.*]], 8
+; CHECK-NEXT:    call void @use(i32 [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = add i32 [[ARG]], 10
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = add i32 %arg, 8
+  call void @use(i32 %t0)
+  %t1 = add i32 %t0, 2
+  ret i32 %t1
+}
+
+define <4 x i32> @vec_add_const_add_const(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_add_const_add_const(
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[ARG:%.*]], <i32 10, i32 10, i32 10, i32 10>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = add <4 x i32> %arg, <i32 8, i32 8, i32 8, i32 8>
+  %t1 = add <4 x i32> %t0, <i32 2, i32 2, i32 2, i32 2>
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_add_const_add_const_extrause(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_add_const_add_const_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = add <4 x i32> [[ARG:%.*]], <i32 8, i32 8, i32 8, i32 8>
+; CHECK-NEXT:    call void @vec_use(<4 x i32> [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[ARG]], <i32 10, i32 10, i32 10, i32 10>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = add <4 x i32> %arg, <i32 8, i32 8, i32 8, i32 8>
+  call void @vec_use(<4 x i32> %t0)
+  %t1 = add <4 x i32> %t0, <i32 2, i32 2, i32 2, i32 2>
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_add_const_add_const_nonsplat(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_add_const_add_const_nonsplat(
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[ARG:%.*]], <i32 23, i32 undef, i32 undef, i32 10>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = add <4 x i32> %arg, <i32 21, i32 undef, i32 8, i32 8>
+  %t1 = add <4 x i32> %t0, <i32 2, i32 3, i32 undef, i32 2>
+  ret <4 x i32> %t1
+}
+
+; (x+c1)-c2
+
+define i32 @add_const_sub_const(i32 %arg) {
+; CHECK-LABEL: @add_const_sub_const(
+; CHECK-NEXT:    [[T1:%.*]] = add i32 [[ARG:%.*]], 6
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = add i32 %arg, 8
+  %t1 = sub i32 %t0, 2
+  ret i32 %t1
+}
+
+define i32 @add_const_sub_const_extrause(i32 %arg) {
+; CHECK-LABEL: @add_const_sub_const_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = add i32 [[ARG:%.*]], 8
+; CHECK-NEXT:    call void @use(i32 [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = add i32 [[ARG]], 6
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = add i32 %arg, 8
+  call void @use(i32 %t0)
+  %t1 = sub i32 %t0, 2
+  ret i32 %t1
+}
+
+define <4 x i32> @vec_add_const_sub_const(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_add_const_sub_const(
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[ARG:%.*]], <i32 6, i32 6, i32 6, i32 6>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = add <4 x i32> %arg, <i32 8, i32 8, i32 8, i32 8>
+  %t1 = sub <4 x i32> %t0, <i32 2, i32 2, i32 2, i32 2>
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_add_const_sub_const_extrause(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_add_const_sub_const_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = add <4 x i32> [[ARG:%.*]], <i32 8, i32 8, i32 8, i32 8>
+; CHECK-NEXT:    call void @vec_use(<4 x i32> [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[ARG]], <i32 6, i32 6, i32 6, i32 6>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = add <4 x i32> %arg, <i32 8, i32 8, i32 8, i32 8>
+  call void @vec_use(<4 x i32> %t0)
+  %t1 = sub <4 x i32> %t0, <i32 2, i32 2, i32 2, i32 2>
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_add_const_sub_const_nonsplat(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_add_const_sub_const_nonsplat(
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[ARG:%.*]], <i32 19, i32 undef, i32 undef, i32 6>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = add <4 x i32> %arg, <i32 21, i32 undef, i32 8, i32 8>
+  %t1 = sub <4 x i32> %t0, <i32 2, i32 3, i32 undef, i32 2>
+  ret <4 x i32> %t1
+}
+
+; c2-(x+c1)
+
+define i32 @add_const_const_sub(i32 %arg) {
+; CHECK-LABEL: @add_const_const_sub(
+; CHECK-NEXT:    [[T1:%.*]] = sub i32 -6, [[ARG:%.*]]
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = add i32 %arg, 8
+  %t1 = sub i32 2, %t0
+  ret i32 %t1
+}
+
+define i32 @add_const_const_sub_extrause(i32 %arg) {
+; CHECK-LABEL: @add_const_const_sub_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = add i32 [[ARG:%.*]], 8
+; CHECK-NEXT:    call void @use(i32 [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = sub i32 -6, [[ARG]]
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = add i32 %arg, 8
+  call void @use(i32 %t0)
+  %t1 = sub i32 2, %t0
+  ret i32 %t1
+}
+
+define <4 x i32> @vec_add_const_const_sub(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_add_const_const_sub(
+; CHECK-NEXT:    [[T1:%.*]] = sub <4 x i32> <i32 -6, i32 -6, i32 -6, i32 -6>, [[ARG:%.*]]
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = add <4 x i32> %arg, <i32 8, i32 8, i32 8, i32 8>
+  %t1 = sub <4 x i32> <i32 2, i32 2, i32 2, i32 2>, %t0
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_add_const_const_sub_extrause(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_add_const_const_sub_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = add <4 x i32> [[ARG:%.*]], <i32 8, i32 8, i32 8, i32 8>
+; CHECK-NEXT:    call void @vec_use(<4 x i32> [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = sub <4 x i32> <i32 -6, i32 -6, i32 -6, i32 -6>, [[ARG]]
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = add <4 x i32> %arg, <i32 8, i32 8, i32 8, i32 8>
+  call void @vec_use(<4 x i32> %t0)
+  %t1 = sub <4 x i32> <i32 2, i32 2, i32 2, i32 2>, %t0
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_add_const_const_sub_nonsplat(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_add_const_const_sub_nonsplat(
+; CHECK-NEXT:    [[T1:%.*]] = sub <4 x i32> <i32 -19, i32 undef, i32 undef, i32 -6>, [[ARG:%.*]]
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = add <4 x i32> %arg, <i32 21, i32 undef, i32 8, i32 8>
+  %t1 = sub <4 x i32> <i32 2, i32 3, i32 undef, i32 2>, %t0
+  ret <4 x i32> %t1
+}
+
+; (x-c1)+c2
+
+define i32 @sub_const_add_const(i32 %arg) {
+; CHECK-LABEL: @sub_const_add_const(
+; CHECK-NEXT:    [[T1:%.*]] = add i32 [[ARG:%.*]], -6
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = sub i32 %arg, 8
+  %t1 = add i32 %t0, 2
+  ret i32 %t1
+}
+
+define i32 @sub_const_add_const_extrause(i32 %arg) {
+; CHECK-LABEL: @sub_const_add_const_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = add i32 [[ARG:%.*]], -8
+; CHECK-NEXT:    call void @use(i32 [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = add i32 [[ARG]], -6
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = sub i32 %arg, 8
+  call void @use(i32 %t0)
+  %t1 = add i32 %t0, 2
+  ret i32 %t1
+}
+
+define <4 x i32> @vec_sub_const_add_const(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_sub_const_add_const(
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[ARG:%.*]], <i32 -6, i32 -6, i32 -6, i32 -6>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> %arg, <i32 8, i32 8, i32 8, i32 8>
+  %t1 = add <4 x i32> %t0, <i32 2, i32 2, i32 2, i32 2>
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_sub_const_add_const_extrause(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_sub_const_add_const_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = add <4 x i32> [[ARG:%.*]], <i32 -8, i32 -8, i32 -8, i32 -8>
+; CHECK-NEXT:    call void @vec_use(<4 x i32> [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[ARG]], <i32 -6, i32 -6, i32 -6, i32 -6>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> %arg, <i32 8, i32 8, i32 8, i32 8>
+  call void @vec_use(<4 x i32> %t0)
+  %t1 = add <4 x i32> %t0, <i32 2, i32 2, i32 2, i32 2>
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_sub_const_add_const_nonsplat(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_sub_const_add_const_nonsplat(
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[ARG:%.*]], <i32 -19, i32 undef, i32 undef, i32 -6>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> %arg, <i32 21, i32 undef, i32 8, i32 8>
+  %t1 = add <4 x i32> %t0, <i32 2, i32 3, i32 undef, i32 2>
+  ret <4 x i32> %t1
+}
+
+; (x-c1)-c2
+
+define i32 @sub_const_sub_const(i32 %arg) {
+; CHECK-LABEL: @sub_const_sub_const(
+; CHECK-NEXT:    [[T1:%.*]] = add i32 [[ARG:%.*]], -10
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = sub i32 %arg, 8
+  %t1 = sub i32 %t0, 2
+  ret i32 %t1
+}
+
+define i32 @sub_const_sub_const_extrause(i32 %arg) {
+; CHECK-LABEL: @sub_const_sub_const_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = add i32 [[ARG:%.*]], -8
+; CHECK-NEXT:    call void @use(i32 [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = add i32 [[ARG]], -10
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = sub i32 %arg, 8
+  call void @use(i32 %t0)
+  %t1 = sub i32 %t0, 2
+  ret i32 %t1
+}
+
+define <4 x i32> @vec_sub_const_sub_const(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_sub_const_sub_const(
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[ARG:%.*]], <i32 -10, i32 -10, i32 -10, i32 -10>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> %arg, <i32 8, i32 8, i32 8, i32 8>
+  %t1 = sub <4 x i32> %t0, <i32 2, i32 2, i32 2, i32 2>
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_sub_const_sub_const_extrause(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_sub_const_sub_const_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = add <4 x i32> [[ARG:%.*]], <i32 -8, i32 -8, i32 -8, i32 -8>
+; CHECK-NEXT:    call void @vec_use(<4 x i32> [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[ARG]], <i32 -10, i32 -10, i32 -10, i32 -10>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> %arg, <i32 8, i32 8, i32 8, i32 8>
+  call void @vec_use(<4 x i32> %t0)
+  %t1 = sub <4 x i32> %t0, <i32 2, i32 2, i32 2, i32 2>
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_sub_const_sub_const_nonsplat(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_sub_const_sub_const_nonsplat(
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[ARG:%.*]], <i32 -23, i32 undef, i32 undef, i32 -10>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> %arg, <i32 21, i32 undef, i32 8, i32 8>
+  %t1 = sub <4 x i32> %t0, <i32 2, i32 3, i32 undef, i32 2>
+  ret <4 x i32> %t1
+}
+
+; c2-(x-c1)
+
+define i32 @sub_const_const_sub(i32 %arg) {
+; CHECK-LABEL: @sub_const_const_sub(
+; CHECK-NEXT:    [[T1:%.*]] = sub i32 10, [[ARG:%.*]]
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = sub i32 %arg, 8
+  %t1 = sub i32 2, %t0
+  ret i32 %t1
+}
+
+define i32 @sub_const_const_sub_extrause(i32 %arg) {
+; CHECK-LABEL: @sub_const_const_sub_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = add i32 [[ARG:%.*]], -8
+; CHECK-NEXT:    call void @use(i32 [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = sub i32 10, [[ARG]]
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = sub i32 %arg, 8
+  call void @use(i32 %t0)
+  %t1 = sub i32 2, %t0
+  ret i32 %t1
+}
+
+define <4 x i32> @vec_sub_const_const_sub(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_sub_const_const_sub(
+; CHECK-NEXT:    [[T1:%.*]] = sub <4 x i32> <i32 10, i32 10, i32 10, i32 10>, [[ARG:%.*]]
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> %arg, <i32 8, i32 8, i32 8, i32 8>
+  %t1 = sub <4 x i32> <i32 2, i32 2, i32 2, i32 2>, %t0
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_sub_const_const_sub_extrause(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_sub_const_const_sub_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = add <4 x i32> [[ARG:%.*]], <i32 -8, i32 -8, i32 -8, i32 -8>
+; CHECK-NEXT:    call void @vec_use(<4 x i32> [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = sub <4 x i32> <i32 10, i32 10, i32 10, i32 10>, [[ARG]]
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> %arg, <i32 8, i32 8, i32 8, i32 8>
+  call void @vec_use(<4 x i32> %t0)
+  %t1 = sub <4 x i32> <i32 2, i32 2, i32 2, i32 2>, %t0
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_sub_const_const_sub_nonsplat(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_sub_const_const_sub_nonsplat(
+; CHECK-NEXT:    [[T1:%.*]] = sub <4 x i32> <i32 23, i32 undef, i32 undef, i32 10>, [[ARG:%.*]]
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> %arg, <i32 21, i32 undef, i32 8, i32 8>
+  %t1 = sub <4 x i32> <i32 2, i32 3, i32 undef, i32 2>, %t0
+  ret <4 x i32> %t1
+}
+
+; (c1-x)+c2
+; FIXME
+
+define i32 @const_sub_add_const(i32 %arg) {
+; CHECK-LABEL: @const_sub_add_const(
+; CHECK-NEXT:    [[T0:%.*]] = sub i32 8, [[ARG:%.*]]
+; CHECK-NEXT:    [[T1:%.*]] = add i32 [[T0]], 2
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = sub i32 8, %arg
+  %t1 = add i32 %t0, 2
+  ret i32 %t1
+}
+
+define i32 @const_sub_add_const_extrause(i32 %arg) {
+; CHECK-LABEL: @const_sub_add_const_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = sub i32 8, [[ARG:%.*]]
+; CHECK-NEXT:    call void @use(i32 [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = add i32 [[T0]], 2
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = sub i32 8, %arg
+  call void @use(i32 %t0)
+  %t1 = add i32 %t0, 2
+  ret i32 %t1
+}
+
+define <4 x i32> @vec_const_sub_add_const(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_const_sub_add_const(
+; CHECK-NEXT:    [[T0:%.*]] = sub <4 x i32> <i32 8, i32 8, i32 8, i32 8>, [[ARG:%.*]]
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[T0]], <i32 2, i32 2, i32 2, i32 2>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> <i32 8, i32 8, i32 8, i32 8>, %arg
+  %t1 = add <4 x i32> %t0, <i32 2, i32 2, i32 2, i32 2>
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_const_sub_add_const_extrause(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_const_sub_add_const_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = sub <4 x i32> <i32 8, i32 8, i32 8, i32 8>, [[ARG:%.*]]
+; CHECK-NEXT:    call void @vec_use(<4 x i32> [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[T0]], <i32 2, i32 2, i32 2, i32 2>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> <i32 8, i32 8, i32 8, i32 8>, %arg
+  call void @vec_use(<4 x i32> %t0)
+  %t1 = add <4 x i32> %t0, <i32 2, i32 2, i32 2, i32 2>
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_const_sub_add_const_nonsplat(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_const_sub_add_const_nonsplat(
+; CHECK-NEXT:    [[T0:%.*]] = sub <4 x i32> <i32 21, i32 undef, i32 8, i32 8>, [[ARG:%.*]]
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[T0]], <i32 2, i32 3, i32 undef, i32 2>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> <i32 21, i32 undef, i32 8, i32 8>, %arg
+  %t1 = add <4 x i32> %t0, <i32 2, i32 3, i32 undef, i32 2>
+  ret <4 x i32> %t1
+}
+
+; (c1-x)-c2
+; FIXME
+
+define i32 @const_sub_sub_const(i32 %arg) {
+; CHECK-LABEL: @const_sub_sub_const(
+; CHECK-NEXT:    [[T0:%.*]] = sub i32 8, [[ARG:%.*]]
+; CHECK-NEXT:    [[T1:%.*]] = add i32 [[T0]], -2
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = sub i32 8, %arg
+  %t1 = sub i32 %t0, 2
+  ret i32 %t1
+}
+
+define i32 @const_sub_sub_const_extrause(i32 %arg) {
+; CHECK-LABEL: @const_sub_sub_const_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = sub i32 8, [[ARG:%.*]]
+; CHECK-NEXT:    call void @use(i32 [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = add i32 [[T0]], -2
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = sub i32 8, %arg
+  call void @use(i32 %t0)
+  %t1 = sub i32 %t0, 2
+  ret i32 %t1
+}
+
+define <4 x i32> @vec_const_sub_sub_const(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_const_sub_sub_const(
+; CHECK-NEXT:    [[T0:%.*]] = sub <4 x i32> <i32 8, i32 8, i32 8, i32 8>, [[ARG:%.*]]
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[T0]], <i32 -2, i32 -2, i32 -2, i32 -2>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> <i32 8, i32 8, i32 8, i32 8>, %arg
+  %t1 = sub <4 x i32> %t0, <i32 2, i32 2, i32 2, i32 2>
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_const_sub_sub_const_extrause(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_const_sub_sub_const_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = sub <4 x i32> <i32 8, i32 8, i32 8, i32 8>, [[ARG:%.*]]
+; CHECK-NEXT:    call void @vec_use(<4 x i32> [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[T0]], <i32 -2, i32 -2, i32 -2, i32 -2>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> <i32 8, i32 8, i32 8, i32 8>, %arg
+  call void @vec_use(<4 x i32> %t0)
+  %t1 = sub <4 x i32> %t0, <i32 2, i32 2, i32 2, i32 2>
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_const_sub_sub_const_nonsplat(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_const_sub_sub_const_nonsplat(
+; CHECK-NEXT:    [[T0:%.*]] = sub <4 x i32> <i32 21, i32 undef, i32 8, i32 8>, [[ARG:%.*]]
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[T0]], <i32 -2, i32 -3, i32 undef, i32 -2>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> <i32 21, i32 undef, i32 8, i32 8>, %arg
+  %t1 = sub <4 x i32> %t0, <i32 2, i32 3, i32 undef, i32 2>
+  ret <4 x i32> %t1
+}
+
+; c2-(c1-x)
+; FIXME
+
+define i32 @const_sub_const_sub(i32 %arg) {
+; CHECK-LABEL: @const_sub_const_sub(
+; CHECK-NEXT:    [[T1:%.*]] = add i32 [[ARG:%.*]], -6
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = sub i32 8, %arg
+  %t1 = sub i32 2, %t0
+  ret i32 %t1
+}
+
+define i32 @const_sub_const_sub_extrause(i32 %arg) {
+; CHECK-LABEL: @const_sub_const_sub_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = sub i32 8, [[ARG:%.*]]
+; CHECK-NEXT:    call void @use(i32 [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = sub i32 2, [[T0]]
+; CHECK-NEXT:    ret i32 [[T1]]
+;
+  %t0 = sub i32 8, %arg
+  call void @use(i32 %t0)
+  %t1 = sub i32 2, %t0
+  ret i32 %t1
+}
+
+define <4 x i32> @vec_const_sub_const_sub(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_const_sub_const_sub(
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[ARG:%.*]], <i32 -6, i32 -6, i32 -6, i32 -6>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> <i32 8, i32 8, i32 8, i32 8>, %arg
+  %t1 = sub <4 x i32> <i32 2, i32 2, i32 2, i32 2>, %t0
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_const_sub_const_sub_extrause(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_const_sub_const_sub_extrause(
+; CHECK-NEXT:    [[T0:%.*]] = sub <4 x i32> <i32 8, i32 8, i32 8, i32 8>, [[ARG:%.*]]
+; CHECK-NEXT:    call void @vec_use(<4 x i32> [[T0]])
+; CHECK-NEXT:    [[T1:%.*]] = sub <4 x i32> <i32 2, i32 2, i32 2, i32 2>, [[T0]]
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> <i32 8, i32 8, i32 8, i32 8>, %arg
+  call void @vec_use(<4 x i32> %t0)
+  %t1 = sub <4 x i32> <i32 2, i32 2, i32 2, i32 2>, %t0
+  ret <4 x i32> %t1
+}
+
+define <4 x i32> @vec_const_sub_const_sub_nonsplat(<4 x i32> %arg) {
+; CHECK-LABEL: @vec_const_sub_const_sub_nonsplat(
+; CHECK-NEXT:    [[T1:%.*]] = add <4 x i32> [[ARG:%.*]], <i32 -19, i32 undef, i32 undef, i32 -6>
+; CHECK-NEXT:    ret <4 x i32> [[T1]]
+;
+  %t0 = sub <4 x i32> <i32 21, i32 undef, i32 8, i32 8>, %arg
+  %t1 = sub <4 x i32> <i32 2, i32 3, i32 undef, i32 2>, %t0
+  ret <4 x i32> %t1
+}