diff options
Diffstat (limited to 'lib/Target/README.txt')
| -rw-r--r-- | lib/Target/README.txt | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/lib/Target/README.txt b/lib/Target/README.txt index 33941f451a..99616b47c8 100644 --- a/lib/Target/README.txt +++ b/lib/Target/README.txt @@ -2238,4 +2238,23 @@ missed cases: //===---------------------------------------------------------------------===// +define i1 @test1(i32 %x) nounwind { + %and = and i32 %x, 3 + %cmp = icmp ult i32 %and, 2 + ret i1 %cmp +} + +Can be folded to (x & 2) == 0. + +define i1 @test2(i32 %x) nounwind { + %and = and i32 %x, 3 + %cmp = icmp ugt i32 %and, 1 + ret i1 %cmp +} +Can be folded to (x & 2) != 0. + +SimplifyDemandedBits shrinks the "and" constant to 2 but instcombine misses the +icmp transform. + +//===---------------------------------------------------------------------===// |