|  | ; If we have an 'and' of the result of an 'or', and one of the 'or' operands | 
|  | ; cannot have contributed any of the resultant bits, delete the or.  This | 
|  | ; occurs for very common C/C++ code like this: | 
|  | ; | 
|  | ; struct foo { int A : 16; int B : 16; }; | 
|  | ; void test(struct foo *F, int X, int Y) { | 
|  | ;        F->A = X; F->B = Y; | 
|  | ; } | 
|  | ; | 
|  | ; Which corresponds to test1. | 
|  | ; | 
|  | ; This tests arbitrary precision integers. | 
|  |  | 
|  | ; RUN: opt %s -instcombine | llvm-dis | not grep {or } | 
|  | ; END. | 
|  |  | 
|  | define i17 @test1(i17 %X, i17 %Y) { | 
|  | %A = and i17 %X, 7 | 
|  | %B = and i17 %Y, 8 | 
|  | %C = or i17 %A, %B | 
|  | %D = and i17 %C, 7  ;; This cannot include any bits from %Y! | 
|  | ret i17 %D | 
|  | } | 
|  |  | 
|  | define i49 @test3(i49 %X, i49 %Y) { | 
|  | %B = shl i49 %Y, 1 | 
|  | %C = or i49 %X, %B | 
|  | %D = and i49 %C, 1  ;; This cannot include any bits from %Y! | 
|  | ret i49 %D | 
|  | } | 
|  |  | 
|  | define i67 @test4(i67 %X, i67 %Y) { | 
|  | %B = lshr i67 %Y, 66 | 
|  | %C = or i67 %X, %B | 
|  | %D = and i67 %C, 2  ;; This cannot include any bits from %Y! | 
|  | ret i67 %D | 
|  | } | 
|  |  | 
|  | define i231 @or_test1(i231 %X, i231 %Y) { | 
|  | %A = and i231 %X, 1 | 
|  | %B = or i231 %A, 1     ;; This cannot include any bits from X! | 
|  | ret i231 %B | 
|  | } | 
|  |  | 
|  | define i7 @or_test2(i7 %X, i7 %Y) { | 
|  | %A = shl i7 %X, 6 | 
|  | %B = or i7 %A, 64     ;; This cannot include any bits from X! | 
|  | ret i7 %B | 
|  | } | 
|  |  |