llvm-6502/test/Transforms/InstCombine/sub.ll
Bill Wendling e1196d6d3e Instcombine was illegally transforming -X/C into X/-C when either X or C
overflowed on negation. This commit checks to make sure that neithe C nor X
overflows. This requires that the RHS of X (a subtract instruction) be a
constant integer.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60275 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-30 03:42:12 +00:00

149 lines
3.3 KiB
LLVM

; This test makes sure that these instructions are properly eliminated.
;
; RUN: llvm-as < %s | opt -instcombine | llvm-dis | \
; RUN: grep -v {sub i32 %Cok, %Bok} | grep -v {sub i32 0, %Aok} | not grep sub
define i32 @test1(i32 %A) {
%B = sub i32 %A, %A ; <i32> [#uses=1]
ret i32 %B
}
define i32 @test2(i32 %A) {
%B = sub i32 %A, 0 ; <i32> [#uses=1]
ret i32 %B
}
define i32 @test3(i32 %A) {
%B = sub i32 0, %A ; <i32> [#uses=1]
%C = sub i32 0, %B ; <i32> [#uses=1]
ret i32 %C
}
define i32 @test4(i32 %A, i32 %x) {
%B = sub i32 0, %A ; <i32> [#uses=1]
%C = sub i32 %x, %B ; <i32> [#uses=1]
ret i32 %C
}
define i32 @test5(i32 %A, i32 %Bok, i32 %Cok) {
%D = sub i32 %Bok, %Cok ; <i32> [#uses=1]
%E = sub i32 %A, %D ; <i32> [#uses=1]
ret i32 %E
}
define i32 @test6(i32 %A, i32 %B) {
%C = and i32 %A, %B ; <i32> [#uses=1]
%D = sub i32 %A, %C ; <i32> [#uses=1]
ret i32 %D
}
define i32 @test7(i32 %A) {
%B = sub i32 -1, %A ; <i32> [#uses=1]
ret i32 %B
}
define i32 @test8(i32 %A) {
%B = mul i32 9, %A ; <i32> [#uses=1]
%C = sub i32 %B, %A ; <i32> [#uses=1]
ret i32 %C
}
define i32 @test9(i32 %A) {
%B = mul i32 3, %A ; <i32> [#uses=1]
%C = sub i32 %A, %B ; <i32> [#uses=1]
ret i32 %C
}
define i32 @test10(i32 %A, i32 %B) {
%C = sub i32 0, %A ; <i32> [#uses=1]
%D = sub i32 0, %B ; <i32> [#uses=1]
%E = mul i32 %C, %D ; <i32> [#uses=1]
ret i32 %E
}
define i32 @test10.upgrd.1(i32 %A) {
%C = sub i32 0, %A ; <i32> [#uses=1]
%E = mul i32 %C, 7 ; <i32> [#uses=1]
ret i32 %E
}
define i1 @test11(i8 %A, i8 %B) {
%C = sub i8 %A, %B ; <i8> [#uses=1]
%cD = icmp ne i8 %C, 0 ; <i1> [#uses=1]
ret i1 %cD
}
define i32 @test12(i32 %A) {
%B = ashr i32 %A, 31 ; <i32> [#uses=1]
%C = sub i32 0, %B ; <i32> [#uses=1]
ret i32 %C
}
define i32 @test13(i32 %A) {
%B = lshr i32 %A, 31 ; <i32> [#uses=1]
%C = sub i32 0, %B ; <i32> [#uses=1]
ret i32 %C
}
define i32 @test14(i32 %A) {
%B = lshr i32 %A, 31 ; <i32> [#uses=1]
%C = bitcast i32 %B to i32 ; <i32> [#uses=1]
%D = sub i32 0, %C ; <i32> [#uses=1]
ret i32 %D
}
define i32 @test15(i32 %A, i32 %B) {
%C = sub i32 0, %A ; <i32> [#uses=1]
%D = srem i32 %B, %C ; <i32> [#uses=1]
ret i32 %D
}
define i32 @test16(i32 %A) {
%X = sdiv i32 %A, 1123 ; <i32> [#uses=1]
%Y = sub i32 0, %X ; <i32> [#uses=1]
ret i32 %Y
}
; Can't fold subtract here because negation it might oveflow.
; PR3142
define i32 @test17(i32 %Aok) {
%B = sub i32 0, %Aok ; <i32> [#uses=1]
%C = sdiv i32 %B, 1234 ; <i32> [#uses=1]
ret i32 %C
}
define i64 @test18(i64 %Y) {
%tmp.4 = shl i64 %Y, 2 ; <i64> [#uses=1]
%tmp.12 = shl i64 %Y, 2 ; <i64> [#uses=1]
%tmp.8 = sub i64 %tmp.4, %tmp.12 ; <i64> [#uses=1]
ret i64 %tmp.8
}
define i32 @test19(i32 %X, i32 %Y) {
%Z = sub i32 %X, %Y ; <i32> [#uses=1]
%Q = add i32 %Z, %Y ; <i32> [#uses=1]
ret i32 %Q
}
define i1 @test20(i32 %g, i32 %h) {
%tmp.2 = sub i32 %g, %h ; <i32> [#uses=1]
%tmp.4 = icmp ne i32 %tmp.2, %g ; <i1> [#uses=1]
ret i1 %tmp.4
}
define i1 @test21(i32 %g, i32 %h) {
%tmp.2 = sub i32 %g, %h ; <i32> [#uses=1]
%tmp.4 = icmp ne i32 %tmp.2, %g ; <i1> [#uses=1]
ret i1 %tmp.4
}
; PR2298
define i8 @test22(i32 %a, i32 %b) zeroext nounwind {
%tmp2 = sub i32 0, %a ; <i32> [#uses=1]
%tmp4 = sub i32 0, %b ; <i32> [#uses=1]
%tmp5 = icmp eq i32 %tmp2, %tmp4 ; <i1> [#uses=1]
%retval89 = zext i1 %tmp5 to i8 ; <i8> [#uses=1]
ret i8 %retval89
}