--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/Transforms/InstCombine/sub.ll	Thu Dec 12 13:56:28 2013 +0900
@@ -0,0 +1,394 @@
+target datalayout = "e-p:64:64:64-p1:16:16:16-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
+
+; Optimize subtracts.
+;
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+define i32 @test1(i32 %A) {
+	%B = sub i32 %A, %A
+	ret i32 %B
+; CHECK-LABEL: @test1(
+; CHECK: ret i32 0
+}
+
+define i32 @test2(i32 %A) {
+	%B = sub i32 %A, 0
+	ret i32 %B
+; CHECK-LABEL: @test2(
+; CHECK: ret i32 %A
+}
+
+define i32 @test3(i32 %A) {
+	%B = sub i32 0, %A
+	%C = sub i32 0, %B
+	ret i32 %C
+; CHECK-LABEL: @test3(
+; CHECK: ret i32 %A
+}
+
+define i32 @test4(i32 %A, i32 %x) {
+	%B = sub i32 0, %A
+	%C = sub i32 %x, %B
+	ret i32 %C
+; CHECK-LABEL: @test4(
+; CHECK: %C = add i32 %x, %A
+; CHECK: ret i32 %C
+}
+
+define i32 @test5(i32 %A, i32 %B, i32 %C) {
+	%D = sub i32 %B, %C
+	%E = sub i32 %A, %D
+	ret i32 %E
+; CHECK-LABEL: @test5(
+; CHECK: %D1 = sub i32 %C, %B
+; CHECK: %E = add
+; CHECK: ret i32 %E
+}
+
+define i32 @test6(i32 %A, i32 %B) {
+	%C = and i32 %A, %B
+	%D = sub i32 %A, %C
+	ret i32 %D
+; CHECK-LABEL: @test6(
+; CHECK-NEXT: xor i32 %B, -1
+; CHECK-NEXT: %D = and i32
+; CHECK-NEXT: ret i32 %D
+}
+
+define i32 @test7(i32 %A) {
+	%B = sub i32 -1, %A
+	ret i32 %B
+; CHECK-LABEL: @test7(
+; CHECK: %B = xor i32 %A, -1
+; CHECK: ret i32 %B
+}
+
+define i32 @test8(i32 %A) {
+	%B = mul i32 9, %A
+	%C = sub i32 %B, %A
+	ret i32 %C
+; CHECK-LABEL: @test8(
+; CHECK: %C = shl i32 %A, 3
+; CHECK: ret i32 %C
+}
+
+define i32 @test9(i32 %A) {
+	%B = mul i32 3, %A
+	%C = sub i32 %A, %B
+	ret i32 %C
+; CHECK-LABEL: @test9(
+; CHECK: %C = mul i32 %A, -2
+; CHECK: ret i32 %C
+}
+
+define i32 @test10(i32 %A, i32 %B) {
+	%C = sub i32 0, %A
+	%D = sub i32 0, %B
+	%E = mul i32 %C, %D
+	ret i32 %E
+; CHECK-LABEL: @test10(
+; CHECK: %E = mul i32 %A, %B
+; CHECK: ret i32 %E
+}
+
+define i32 @test10a(i32 %A) {
+	%C = sub i32 0, %A
+	%E = mul i32 %C, 7
+	ret i32 %E
+; CHECK-LABEL: @test10a(
+; CHECK: %E = mul i32 %A, -7
+; CHECK: ret i32 %E
+}
+
+define i1 @test11(i8 %A, i8 %B) {
+	%C = sub i8 %A, %B
+	%cD = icmp ne i8 %C, 0
+	ret i1 %cD
+; CHECK-LABEL: @test11(
+; CHECK: %cD = icmp ne i8 %A, %B
+; CHECK: ret i1 %cD
+}
+
+define i32 @test12(i32 %A) {
+	%B = ashr i32 %A, 31
+	%C = sub i32 0, %B
+	ret i32 %C
+; CHECK-LABEL: @test12(
+; CHECK: %C = lshr i32 %A, 31
+; CHECK: ret i32 %C
+}
+
+define i32 @test13(i32 %A) {
+	%B = lshr i32 %A, 31
+	%C = sub i32 0, %B
+	ret i32 %C
+; CHECK-LABEL: @test13(
+; CHECK: %C = ashr i32 %A, 31
+; CHECK: ret i32 %C
+}
+
+define i32 @test14(i32 %A) {
+	%B = lshr i32 %A, 31
+	%C = bitcast i32 %B to i32
+	%D = sub i32 0, %C
+	ret i32 %D
+; CHECK-LABEL: @test14(
+; CHECK: %D = ashr i32 %A, 31
+; CHECK: ret i32 %D
+}
+
+define i32 @test15(i32 %A, i32 %B) {
+	%C = sub i32 0, %A
+	%D = srem i32 %B, %C
+	ret i32 %D
+; CHECK-LABEL: @test15(
+; CHECK: %D = srem i32 %B, %A
+; CHECK: ret i32 %D
+}
+
+define i32 @test16(i32 %A) {
+	%X = sdiv i32 %A, 1123
+	%Y = sub i32 0, %X
+	ret i32 %Y
+; CHECK-LABEL: @test16(
+; CHECK: %Y = sdiv i32 %A, -1123
+; CHECK: ret i32 %Y
+}
+
+; Can't fold subtract here because negation it might oveflow.
+; PR3142
+define i32 @test17(i32 %A) {
+	%B = sub i32 0, %A
+	%C = sdiv i32 %B, 1234
+	ret i32 %C
+; CHECK-LABEL: @test17(
+; CHECK: %B = sub i32 0, %A
+; CHECK: %C = sdiv i32 %B, 1234
+; CHECK: ret i32 %C
+}
+
+define i64 @test18(i64 %Y) {
+	%tmp.4 = shl i64 %Y, 2
+	%tmp.12 = shl i64 %Y, 2
+	%tmp.8 = sub i64 %tmp.4, %tmp.12
+	ret i64 %tmp.8
+; CHECK-LABEL: @test18(
+; CHECK: ret i64 0
+}
+
+define i32 @test19(i32 %X, i32 %Y) {
+	%Z = sub i32 %X, %Y
+	%Q = add i32 %Z, %Y
+	ret i32 %Q
+; CHECK-LABEL: @test19(
+; CHECK: ret i32 %X
+}
+
+define i1 @test20(i32 %g, i32 %h) {
+	%tmp.2 = sub i32 %g, %h
+	%tmp.4 = icmp ne i32 %tmp.2, %g
+	ret i1 %tmp.4
+; CHECK-LABEL: @test20(
+; CHECK: %tmp.4 = icmp ne i32 %h, 0
+; CHECK: ret i1 %tmp.4
+}
+
+define i1 @test21(i32 %g, i32 %h) {
+	%tmp.2 = sub i32 %g, %h
+	%tmp.4 = icmp ne i32 %tmp.2, %g
+        ret i1 %tmp.4
+; CHECK-LABEL: @test21(
+; CHECK: %tmp.4 = icmp ne i32 %h, 0
+; CHECK: ret i1 %tmp.4
+}
+
+; PR2298
+define zeroext i1 @test22(i32 %a, i32 %b)  nounwind  {
+	%tmp2 = sub i32 0, %a
+	%tmp4 = sub i32 0, %b
+	%tmp5 = icmp eq i32 %tmp2, %tmp4
+	ret i1 %tmp5
+; CHECK-LABEL: @test22(
+; CHECK: %tmp5 = icmp eq i32 %b, %a
+; CHECK: ret i1 %tmp5
+}
+
+; rdar://7362831
+define i32 @test23(i8* %P, i64 %A){
+  %B = getelementptr inbounds i8* %P, i64 %A
+  %C = ptrtoint i8* %B to i64
+  %D = trunc i64 %C to i32
+  %E = ptrtoint i8* %P to i64
+  %F = trunc i64 %E to i32
+  %G = sub i32 %D, %F
+  ret i32 %G
+; CHECK-LABEL: @test23(
+; CHECK-NEXT: = trunc i64 %A to i32
+; CHECK-NEXT: ret i32
+}
+
+define i8 @test23_as1(i8 addrspace(1)* %P, i16 %A) {
+; CHECK: @test23_as1
+; CHECK-NEXT: = trunc i16 %A to i8
+; CHECK-NEXT: ret i8
+  %B = getelementptr inbounds i8 addrspace(1)* %P, i16 %A
+  %C = ptrtoint i8 addrspace(1)* %B to i16
+  %D = trunc i16 %C to i8
+  %E = ptrtoint i8 addrspace(1)* %P to i16
+  %F = trunc i16 %E to i8
+  %G = sub i8 %D, %F
+  ret i8 %G
+}
+
+define i64 @test24(i8* %P, i64 %A){
+  %B = getelementptr inbounds i8* %P, i64 %A
+  %C = ptrtoint i8* %B to i64
+  %E = ptrtoint i8* %P to i64
+  %G = sub i64 %C, %E
+  ret i64 %G
+; CHECK-LABEL: @test24(
+; CHECK-NEXT: ret i64 %A
+}
+
+define i16 @test24_as1(i8 addrspace(1)* %P, i16 %A) {
+; CHECK: @test24_as1
+; CHECK-NEXT: ret i16 %A
+  %B = getelementptr inbounds i8 addrspace(1)* %P, i16 %A
+  %C = ptrtoint i8 addrspace(1)* %B to i16
+  %E = ptrtoint i8 addrspace(1)* %P to i16
+  %G = sub i16 %C, %E
+  ret i16 %G
+}
+
+define i64 @test24a(i8* %P, i64 %A){
+  %B = getelementptr inbounds i8* %P, i64 %A
+  %C = ptrtoint i8* %B to i64
+  %E = ptrtoint i8* %P to i64
+  %G = sub i64 %E, %C
+  ret i64 %G
+; CHECK-LABEL: @test24a(
+; CHECK-NEXT: sub i64 0, %A
+; CHECK-NEXT: ret i64
+}
+
+define i16 @test24a_as1(i8 addrspace(1)* %P, i16 %A) {
+; CHECK: @test24a_as1
+; CHECK-NEXT: sub i16 0, %A
+; CHECK-NEXT: ret i16
+  %B = getelementptr inbounds i8 addrspace(1)* %P, i16 %A
+  %C = ptrtoint i8 addrspace(1)* %B to i16
+  %E = ptrtoint i8 addrspace(1)* %P to i16
+  %G = sub i16 %E, %C
+  ret i16 %G
+}
+
+
+@Arr = external global [42 x i16]
+
+define i64 @test24b(i8* %P, i64 %A){
+  %B = getelementptr inbounds [42 x i16]* @Arr, i64 0, i64 %A
+  %C = ptrtoint i16* %B to i64
+  %G = sub i64 %C, ptrtoint ([42 x i16]* @Arr to i64)
+  ret i64 %G
+; CHECK-LABEL: @test24b(
+; CHECK-NEXT: shl nuw i64 %A, 1
+; CHECK-NEXT: ret i64
+}
+
+
+define i64 @test25(i8* %P, i64 %A){
+  %B = getelementptr inbounds [42 x i16]* @Arr, i64 0, i64 %A
+  %C = ptrtoint i16* %B to i64
+  %G = sub i64 %C, ptrtoint (i16* getelementptr ([42 x i16]* @Arr, i64 1, i64 0) to i64)
+  ret i64 %G
+; CHECK-LABEL: @test25(
+; CHECK-NEXT: shl nuw i64 %A, 1
+; CHECK-NEXT: add i64 {{.*}}, -84
+; CHECK-NEXT: ret i64
+}
+
+@Arr_as1 = external addrspace(1) global [42 x i16]
+
+define i16 @test25_as1(i8 addrspace(1)* %P, i64 %A) {
+; CHECK: @test25_as1
+; CHECK-NEXT: %1 = trunc i64 %A to i16
+; CHECK-NEXT: shl nuw i16 %1, 1
+; CHECK-NEXT: add i16 {{.*}}, -84
+; CHECK-NEXT: ret i16
+  %B = getelementptr inbounds [42 x i16] addrspace(1)* @Arr_as1, i64 0, i64 %A
+  %C = ptrtoint i16 addrspace(1)* %B to i16
+  %G = sub i16 %C, ptrtoint (i16 addrspace(1)* getelementptr ([42 x i16] addrspace(1)* @Arr_as1, i64 1, i64 0) to i16)
+  ret i16 %G
+}
+
+define i32 @test26(i32 %x) {
+  %shl = shl i32 3, %x
+  %neg = sub i32 0, %shl
+  ret i32 %neg
+; CHECK-LABEL: @test26(
+; CHECK-NEXT: shl i32 -3
+; CHECK-NEXT: ret i32
+}
+
+define i32 @test27(i32 %x, i32 %y) {
+  %mul = mul i32 %y, -8
+  %sub = sub i32 %x, %mul
+  ret i32 %sub
+; CHECK-LABEL: @test27(
+; CHECK-NEXT: shl i32 %y, 3
+; CHECK-NEXT: add i32
+; CHECK-NEXT: ret i32
+}
+
+define i32 @test28(i32 %x, i32 %y, i32 %z) {
+  %neg = sub i32 0, %z
+  %mul = mul i32 %neg, %y
+  %sub = sub i32 %x, %mul
+  ret i32 %sub
+; CHECK-LABEL: @test28(
+; CHECK-NEXT: mul i32 %z, %y
+; CHECK-NEXT: add i32
+; CHECK-NEXT: ret i32
+}
+
+define i64 @test29(i8* %foo, i64 %i, i64 %j) {
+  %gep1 = getelementptr inbounds i8* %foo, i64 %i
+  %gep2 = getelementptr inbounds i8* %foo, i64 %j
+  %cast1 = ptrtoint i8* %gep1 to i64
+  %cast2 = ptrtoint i8* %gep2 to i64
+  %sub = sub i64 %cast1, %cast2
+  ret i64 %sub
+; CHECK-LABEL: @test29(
+; CHECK-NEXT: sub i64 %i, %j
+; CHECK-NEXT: ret i64
+}
+
+define i64 @test30(i8* %foo, i64 %i, i64 %j) {
+  %bit = bitcast i8* %foo to i32*
+  %gep1 = getelementptr inbounds i32* %bit, i64 %i
+  %gep2 = getelementptr inbounds i8* %foo, i64 %j
+  %cast1 = ptrtoint i32* %gep1 to i64
+  %cast2 = ptrtoint i8* %gep2 to i64
+  %sub = sub i64 %cast1, %cast2
+  ret i64 %sub
+; CHECK-LABEL: @test30(
+; CHECK-NEXT: %gep1.idx = shl nuw i64 %i, 2
+; CHECK-NEXT: sub i64 %gep1.idx, %j
+; CHECK-NEXT: ret i64
+}
+
+define i16 @test30_as1(i8 addrspace(1)* %foo, i16 %i, i16 %j) {
+; CHECK-LABEL: @test30_as1(
+; CHECK-NEXT: %gep1.idx = shl nuw i16 %i, 2
+; CHECK-NEXT: sub i16 %gep1.idx, %j
+; CHECK-NEXT: ret i16
+  %bit = bitcast i8 addrspace(1)* %foo to i32 addrspace(1)*
+  %gep1 = getelementptr inbounds i32 addrspace(1)* %bit, i16 %i
+  %gep2 = getelementptr inbounds i8 addrspace(1)* %foo, i16 %j
+  %cast1 = ptrtoint i32 addrspace(1)* %gep1 to i16
+  %cast2 = ptrtoint i8 addrspace(1)* %gep2 to i16
+  %sub = sub i16 %cast1, %cast2
+  ret i16 %sub
+}
+
+