llvm-6502/test/CodeGen/Generic/2008-02-04-Ctlz.ll
Duncan Sands d462ba8539 Teach LegalizeTypes how to expand and promote CTLZ,
CTTZ and CTPOP.  The expansion code differs from
that in LegalizeDAG in that it chooses to take the
CTLZ/CTTZ count from the Hi/Lo part depending on
whether the Hi/Lo value is zero, not on whether
CTLZ/CTTZ of Hi/Lo returned 32 (or whatever the
width of the type is) for it.  I made this change
because the optimizers may well know that Hi/Lo
is zero and exploit it.  The promotion code for
CTTZ also differs from that in LegalizeDAG: it
uses an "or" to get the right result when the
original value is zero, rather than using a compare
and select.  This also means the value doesn't
need to be zero extended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47075 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-13 18:01:53 +00:00

22 lines
906 B
LLVM

; RUN: llvm-as < %s | llc
@.str = internal constant [14 x i8] c"%lld %d %d %d\00"
define i32 @main(i64 %arg) nounwind {
entry:
%tmp37 = tail call i64 @llvm.ctlz.i64( i64 %arg ) ; <i64> [#uses=1]
%tmp47 = tail call i64 @llvm.cttz.i64( i64 %arg ) ; <i64> [#uses=1]
%tmp57 = tail call i64 @llvm.ctpop.i64( i64 %arg ) ; <i64> [#uses=1]
%tmp38 = trunc i64 %tmp37 to i32 ; <i32>:0 [#uses=1]
%tmp48 = trunc i64 %tmp47 to i32 ; <i32>:0 [#uses=1]
%tmp58 = trunc i64 %tmp57 to i32 ; <i32>:0 [#uses=1]
%tmp40 = tail call i32 (i8*, ...)* @printf( i8* noalias getelementptr ([14 x i8]* @.str, i32 0, i32 0), i64 %arg, i32 %tmp38, i32 %tmp48, i32 %tmp58 ) nounwind ; <i32> [#uses=0]
ret i32 0
}
declare i32 @printf(i8* noalias , ...) nounwind
declare i64 @llvm.ctlz.i64(i64) nounwind readnone
declare i64 @llvm.cttz.i64(i64) nounwind readnone
declare i64 @llvm.ctpop.i64(i64) nounwind readnone