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Chris Lattner584e3832005-01-01 16:14:18 +00001; If we have an 'and' of the result of an 'or', and one of the 'or' operands
2; cannot have contributed any of the resultant bits, delete the or. This
3; occurs for very common C/C++ code like this:
4;
5; struct foo { int A : 16; int B : 16; };
6; void test(struct foo *F, int X, int Y) {
7; F->A = X; F->B = Y;
8; }
9;
10; Which corresponds to test1.
11
Reid Spencer91948d42007-04-14 20:13:02 +000012; RUN: llvm-upgrade < %s | llvm-as | opt -instcombine | llvm-dis | \
13; RUN: not grep {or }
Reid Spencerede8c3b2007-04-15 07:38:21 +000014; END.
Chris Lattner584e3832005-01-01 16:14:18 +000015
16int %test1(int %X, int %Y) {
17 %A = and int %X, 7
18 %B = and int %Y, 8
19 %C = or int %A, %B
20 %D = and int %C, 7 ;; This cannot include any bits from %Y!
21 ret int %D
22}
23
24int %test2(int %X, ubyte %Y) {
25 %B = cast ubyte %Y to int
26 %C = or int %X, %B
27 %D = and int %C, 65536 ;; This cannot include any bits from %Y!
28 ret int %D
29}
30
31int %test3(int %X, int %Y) {
32 %B = shl int %Y, ubyte 1
33 %C = or int %X, %B
34 %D = and int %C, 1 ;; This cannot include any bits from %Y!
35 ret int %D
36}
37
38uint %test4(uint %X, uint %Y) {
39 %B = shr uint %Y, ubyte 31
40 %C = or uint %X, %B
41 %D = and uint %C, 2 ;; This cannot include any bits from %Y!
42 ret uint %D
43}
44
45int %or_test1(int %X, int %Y) {
46 %A = and int %X, 1
47 %B = or int %A, 1 ;; This cannot include any bits from X!
48 ret int %B
49}
50
51ubyte %or_test2(ubyte %X, ubyte %Y) {
52 %A = shl ubyte %X, ubyte 7
53 %B = or ubyte %A, 128 ;; This cannot include any bits from X!
54 ret ubyte %B
55}
56