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.
llvm-svn: 47075
diff --git a/llvm/test/CodeGen/Generic/2008-02-04-Ctlz.ll b/llvm/test/CodeGen/Generic/2008-02-04-Ctlz.ll
index 5a560aa..4639b6f 100644
--- a/llvm/test/CodeGen/Generic/2008-02-04-Ctlz.ll
+++ b/llvm/test/CodeGen/Generic/2008-02-04-Ctlz.ll
@@ -1,22 +1,21 @@
; RUN: llvm-as < %s | llc
-@.str3 = external constant [56 x i8] ; <[56 x i8]*> [#uses=1]
+@.str = internal constant [14 x i8] c"%lld %d %d %d\00"
-define i32 @main() nounwind {
+define i32 @main(i64 %arg) nounwind {
entry:
- br label %bb30
-
-bb30: ; preds = %bb30, %entry
- %l.024 = phi i64 [ -10000, %entry ], [ 0, %bb30 ] ; <i64> [#uses=2]
- %tmp37 = tail call i64 @llvm.ctlz.i64( i64 %l.024 ) ; <i64> [#uses=1]
- trunc i64 %tmp37 to i32 ; <i32>:0 [#uses=1]
- %tmp40 = tail call i32 (i8*, ...)* @printf( i8* noalias getelementptr ([56 x i8]* @.str3, i32 0, i32 0), i64 %l.024, i32 %0, i32 0, i32 0 ) nounwind ; <i32> [#uses=0]
- br i1 false, label %bb30, label %bb9.i
-
-bb9.i: ; preds = %bb30
+ %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