assigned to @lattner

How about translating the (x >> 5) & 1 != 0 into (x & 0x0020) instead?

compilable testcase:

int %test(int* %tmp1) {
%tmp = load int* %tmp1 ; [#uses=1]
%tmp = cast int %tmp to uint ; [#uses=1]
%tmp2 = shr uint %tmp, ubyte 5 ; [#uses=1]
%tmp2 = cast uint %tmp2 to int ; [#uses=1]
%tmp3 = and int %tmp2, 1 ; [#uses=1]
%tmp3 = cast int %tmp3 to bool ; [#uses=1]
%tmp34 = cast bool %tmp3 to int ; [#uses=1]
ret int %tmp34
}

Fixed. Testcase here: Transforms/InstCombine/2006-09-15-CastToBool.ll

Patch here:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20060911/037892.html

BTW, instcombine now reduces the function in the testcase to:

int %test(int* %tmp1) {
%tmp = load int* %tmp1 ; [#uses=1]
%tmp = cast int %tmp to uint ; [#uses=1]
%tmp2 = shr uint %tmp, ubyte 5 ; [#uses=1]
%tmp2 = cast uint %tmp2 to int ; [#uses=1]
%tmp34 = and int %tmp2, 1 ; [#uses=1]
ret int %tmp34
}

The shift is required because the function is required to deliver int 1/0, not a bool.

Thanks!

-Chris

Fantastic. Thanks Chris!

*** Bug llvm/llvm-bugzilla-archive#953 has been marked as a duplicate of this bug. ***