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|
; RUN: opt -loop-idiom -mtriple=x86_64 -mcpu=core-avx2 < %s -S | FileCheck -check-prefix=LZCNT --check-prefix=ALL %s
; RUN: opt -loop-idiom -mtriple=x86_64 -mcpu=corei7 < %s -S | FileCheck -check-prefix=NOLZCNT --check-prefix=ALL %s
; Recognize CTLZ builtin pattern.
; Here we'll just convert loop to countable,
; so do not insert builtin if CPU do not support CTLZ
;
; int ctlz_and_other(int n, char *a)
; {
; int i = 0, n0 = n;
; while(n >>= 1) {
; a[i] = (n0 & (1 << i)) ? 1 : 0;
; i++;
; }
; return i;
; }
;
; LZCNT: entry
; LZCNT: %0 = call i32 @llvm.ctlz.i32(i32 %shr8, i1 true)
; LZCNT-NEXT: %1 = sub i32 32, %0
; LZCNT-NEXT: %2 = zext i32 %1 to i64
; LZCNT: %indvars.iv.next.lcssa = phi i64 [ %2, %while.body ]
; LZCNT: %4 = trunc i64 %indvars.iv.next.lcssa to i32
; LZCNT: %i.0.lcssa = phi i32 [ 0, %entry ], [ %4, %while.end.loopexit ]
; LZCNT: ret i32 %i.0.lcssa
; NOLZCNT: entry
; NOLZCNT-NOT: @llvm.ctlz
; Function Attrs: norecurse nounwind uwtable
define i32 @ctlz_and_other(i32 %n, i8* nocapture %a) {
entry:
%shr8 = ashr i32 %n, 1
%tobool9 = icmp eq i32 %shr8, 0
br i1 %tobool9, label %while.end, label %while.body.preheader
while.body.preheader: ; preds = %entry
br label %while.body
while.body: ; preds = %while.body.preheader, %while.body
%indvars.iv = phi i64 [ %indvars.iv.next, %while.body ], [ 0, %while.body.preheader ]
%shr11 = phi i32 [ %shr, %while.body ], [ %shr8, %while.body.preheader ]
%0 = trunc i64 %indvars.iv to i32
%shl = shl i32 1, %0
%and = and i32 %shl, %n
%tobool1 = icmp ne i32 %and, 0
%conv = zext i1 %tobool1 to i8
%arrayidx = getelementptr inbounds i8, i8* %a, i64 %indvars.iv
store i8 %conv, i8* %arrayidx, align 1
%indvars.iv.next = add nuw i64 %indvars.iv, 1
%shr = ashr i32 %shr11, 1
%tobool = icmp eq i32 %shr, 0
br i1 %tobool, label %while.end.loopexit, label %while.body
while.end.loopexit: ; preds = %while.body
%1 = trunc i64 %indvars.iv.next to i32
br label %while.end
while.end: ; preds = %while.end.loopexit, %entry
%i.0.lcssa = phi i32 [ 0, %entry ], [ %1, %while.end.loopexit ]
ret i32 %i.0.lcssa
}
; Recognize CTLZ builtin pattern.
; Here it will replace the loop -
; assume builtin is always profitable.
;
; int ctlz_zero_check(int n)
; {
; int i = 0;
; while(n) {
; n >>= 1;
; i++;
; }
; return i;
; }
;
; ALL: entry
; ALL: %0 = call i32 @llvm.ctlz.i32(i32 %n, i1 true)
; ALL-NEXT: %1 = sub i32 32, %0
; ALL: %inc.lcssa = phi i32 [ %1, %while.body ]
; ALL: %i.0.lcssa = phi i32 [ 0, %entry ], [ %inc.lcssa, %while.end.loopexit ]
; ALL: ret i32 %i.0.lcssa
; Function Attrs: norecurse nounwind readnone uwtable
define i32 @ctlz_zero_check(i32 %n) {
entry:
%tobool4 = icmp eq i32 %n, 0
br i1 %tobool4, label %while.end, label %while.body.preheader
while.body.preheader: ; preds = %entry
br label %while.body
while.body: ; preds = %while.body.preheader, %while.body
%i.06 = phi i32 [ %inc, %while.body ], [ 0, %while.body.preheader ]
%n.addr.05 = phi i32 [ %shr, %while.body ], [ %n, %while.body.preheader ]
%shr = ashr i32 %n.addr.05, 1
%inc = add nsw i32 %i.06, 1
%tobool = icmp eq i32 %shr, 0
br i1 %tobool, label %while.end.loopexit, label %while.body
while.end.loopexit: ; preds = %while.body
br label %while.end
while.end: ; preds = %while.end.loopexit, %entry
%i.0.lcssa = phi i32 [ 0, %entry ], [ %inc, %while.end.loopexit ]
ret i32 %i.0.lcssa
}
; Recognize CTLZ builtin pattern.
; Here it will replace the loop -
; assume builtin is always profitable.
;
; int ctlz(int n)
; {
; int i = 0;
; while(n >>= 1) {
; i++;
; }
; return i;
; }
;
; ALL: entry
; ALL: %0 = ashr i32 %n, 1
; ALL-NEXT: %1 = call i32 @llvm.ctlz.i32(i32 %0, i1 false)
; ALL-NEXT: %2 = sub i32 32, %1
; ALL-NEXT: %3 = add i32 %2, 1
; ALL: %i.0.lcssa = phi i32 [ %2, %while.cond ]
; ALL: ret i32 %i.0.lcssa
; Function Attrs: norecurse nounwind readnone uwtable
define i32 @ctlz(i32 %n) {
entry:
br label %while.cond
while.cond: ; preds = %while.cond, %entry
%n.addr.0 = phi i32 [ %n, %entry ], [ %shr, %while.cond ]
%i.0 = phi i32 [ 0, %entry ], [ %inc, %while.cond ]
%shr = ashr i32 %n.addr.0, 1
%tobool = icmp eq i32 %shr, 0
%inc = add nsw i32 %i.0, 1
br i1 %tobool, label %while.end, label %while.cond
while.end: ; preds = %while.cond
ret i32 %i.0
}
; Recognize CTLZ builtin pattern.
; Here it will replace the loop -
; assume builtin is always profitable.
;
; int ctlz_add(int n, int i0)
; {
; int i = i0;
; while(n >>= 1) {
; i++;
; }
; return i;
; }
;
; ALL: entry
; ALL: %0 = ashr i32 %n, 1
; ALL-NEXT: %1 = call i32 @llvm.ctlz.i32(i32 %0, i1 false)
; ALL-NEXT: %2 = sub i32 32, %1
; ALL-NEXT: %3 = add i32 %2, 1
; ALL-NEXT: %4 = add i32 %2, %i0
; ALL: %i.0.lcssa = phi i32 [ %4, %while.cond ]
; ALL: ret i32 %i.0.lcssa
;
; Function Attrs: norecurse nounwind readnone uwtable
define i32 @ctlz_add(i32 %n, i32 %i0) {
entry:
br label %while.cond
while.cond: ; preds = %while.cond, %entry
%n.addr.0 = phi i32 [ %n, %entry ], [ %shr, %while.cond ]
%i.0 = phi i32 [ %i0, %entry ], [ %inc, %while.cond ]
%shr = ashr i32 %n.addr.0, 1
%tobool = icmp eq i32 %shr, 0
%inc = add nsw i32 %i.0, 1
br i1 %tobool, label %while.end, label %while.cond
while.end: ; preds = %while.cond
ret i32 %i.0
}
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