forked from OSchip/llvm-project
529 lines
17 KiB
LLVM
529 lines
17 KiB
LLVM
; RUN: opt -loop-idiom -mtriple=x86_64 -mcpu=core-avx2 < %s -S | FileCheck -check-prefix=LZCNT --check-prefix=ALL %s
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; RUN: opt -loop-idiom -mtriple=x86_64 -mcpu=corei7 < %s -S | FileCheck -check-prefix=NOLZCNT --check-prefix=ALL %s
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; Recognize CTLZ builtin pattern.
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; Here we'll just convert loop to countable,
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; so do not insert builtin if CPU do not support CTLZ
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;
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; int ctlz_and_other(int n, char *a)
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; {
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; n = n >= 0 ? n : -n;
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; int i = 0, n0 = n;
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; while(n >>= 1) {
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; a[i] = (n0 & (1 << i)) ? 1 : 0;
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; i++;
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; }
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; return i;
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; }
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;
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; LZCNT: entry
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; LZCNT: %0 = call i32 @llvm.ctlz.i32(i32 %shr8, i1 true)
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; LZCNT-NEXT: %1 = sub i32 32, %0
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; LZCNT-NEXT: %2 = zext i32 %1 to i64
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; LZCNT: %indvars.iv.next.lcssa = phi i64 [ %2, %while.body ]
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; LZCNT: %4 = trunc i64 %indvars.iv.next.lcssa to i32
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; LZCNT: %i.0.lcssa = phi i32 [ 0, %entry ], [ %4, %while.end.loopexit ]
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; LZCNT: ret i32 %i.0.lcssa
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; NOLZCNT: entry
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; NOLZCNT-NOT: @llvm.ctlz
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; Function Attrs: norecurse nounwind uwtable
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define i32 @ctlz_and_other(i32 %n, i8* nocapture %a) {
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entry:
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%c = icmp sgt i32 %n, 0
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%negn = sub nsw i32 0, %n
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%abs_n = select i1 %c, i32 %n, i32 %negn
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%shr8 = lshr i32 %abs_n, 1
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%tobool9 = icmp eq i32 %shr8, 0
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br i1 %tobool9, label %while.end, label %while.body.preheader
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while.body.preheader: ; preds = %entry
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br label %while.body
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while.body: ; preds = %while.body.preheader, %while.body
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%indvars.iv = phi i64 [ %indvars.iv.next, %while.body ], [ 0, %while.body.preheader ]
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%shr11 = phi i32 [ %shr, %while.body ], [ %shr8, %while.body.preheader ]
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%0 = trunc i64 %indvars.iv to i32
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%shl = shl i32 1, %0
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%and = and i32 %shl, %abs_n
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%tobool1 = icmp ne i32 %and, 0
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%conv = zext i1 %tobool1 to i8
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%arrayidx = getelementptr inbounds i8, i8* %a, i64 %indvars.iv
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store i8 %conv, i8* %arrayidx, align 1
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%indvars.iv.next = add nuw i64 %indvars.iv, 1
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%shr = ashr i32 %shr11, 1
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%tobool = icmp eq i32 %shr, 0
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br i1 %tobool, label %while.end.loopexit, label %while.body
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while.end.loopexit: ; preds = %while.body
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%1 = trunc i64 %indvars.iv.next to i32
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br label %while.end
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while.end: ; preds = %while.end.loopexit, %entry
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%i.0.lcssa = phi i32 [ 0, %entry ], [ %1, %while.end.loopexit ]
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ret i32 %i.0.lcssa
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}
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; Recognize CTLZ builtin pattern.
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; Here it will replace the loop -
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; assume builtin is always profitable.
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;
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; int ctlz_zero_check(int n)
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; {
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; n = n >= 0 ? n : -n;
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; int i = 0;
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; while(n) {
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; n >>= 1;
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; i++;
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; }
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; return i;
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; }
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;
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; ALL: entry
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; ALL: %0 = call i32 @llvm.ctlz.i32(i32 %abs_n, i1 true)
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; ALL-NEXT: %1 = sub i32 32, %0
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; ALL: %inc.lcssa = phi i32 [ %1, %while.body ]
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; ALL: %i.0.lcssa = phi i32 [ 0, %entry ], [ %inc.lcssa, %while.end.loopexit ]
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; ALL: ret i32 %i.0.lcssa
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; Function Attrs: norecurse nounwind readnone uwtable
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define i32 @ctlz_zero_check(i32 %n) {
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entry:
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%c = icmp sgt i32 %n, 0
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%negn = sub nsw i32 0, %n
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%abs_n = select i1 %c, i32 %n, i32 %negn
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%tobool4 = icmp eq i32 %abs_n, 0
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br i1 %tobool4, label %while.end, label %while.body.preheader
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while.body.preheader: ; preds = %entry
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br label %while.body
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while.body: ; preds = %while.body.preheader, %while.body
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%i.06 = phi i32 [ %inc, %while.body ], [ 0, %while.body.preheader ]
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%n.addr.05 = phi i32 [ %shr, %while.body ], [ %abs_n, %while.body.preheader ]
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%shr = ashr i32 %n.addr.05, 1
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%inc = add nsw i32 %i.06, 1
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%tobool = icmp eq i32 %shr, 0
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br i1 %tobool, label %while.end.loopexit, label %while.body
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while.end.loopexit: ; preds = %while.body
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br label %while.end
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while.end: ; preds = %while.end.loopexit, %entry
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%i.0.lcssa = phi i32 [ 0, %entry ], [ %inc, %while.end.loopexit ]
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ret i32 %i.0.lcssa
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}
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; Recognize CTLZ builtin pattern.
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; Here it will replace the loop -
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; assume builtin is always profitable.
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;
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; int ctlz_zero_check_lshr(int n)
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; {
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; int i = 0;
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; while(n) {
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; n >>= 1;
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; i++;
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; }
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; return i;
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; }
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;
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; ALL: entry
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; ALL: %0 = call i32 @llvm.ctlz.i32(i32 %n, i1 true)
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; ALL-NEXT: %1 = sub i32 32, %0
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; ALL: %inc.lcssa = phi i32 [ %1, %while.body ]
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; ALL: %i.0.lcssa = phi i32 [ 0, %entry ], [ %inc.lcssa, %while.end.loopexit ]
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; ALL: ret i32 %i.0.lcssa
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; Function Attrs: norecurse nounwind readnone uwtable
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define i32 @ctlz_zero_check_lshr(i32 %n) {
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entry:
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%tobool4 = icmp eq i32 %n, 0
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br i1 %tobool4, label %while.end, label %while.body.preheader
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while.body.preheader: ; preds = %entry
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br label %while.body
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while.body: ; preds = %while.body.preheader, %while.body
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%i.06 = phi i32 [ %inc, %while.body ], [ 0, %while.body.preheader ]
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%n.addr.05 = phi i32 [ %shr, %while.body ], [ %n, %while.body.preheader ]
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%shr = lshr i32 %n.addr.05, 1
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%inc = add nsw i32 %i.06, 1
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%tobool = icmp eq i32 %shr, 0
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br i1 %tobool, label %while.end.loopexit, label %while.body
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while.end.loopexit: ; preds = %while.body
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br label %while.end
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while.end: ; preds = %while.end.loopexit, %entry
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%i.0.lcssa = phi i32 [ 0, %entry ], [ %inc, %while.end.loopexit ]
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ret i32 %i.0.lcssa
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}
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; Recognize CTLZ builtin pattern.
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; Here it will replace the loop -
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; assume builtin is always profitable.
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;
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; int ctlz(int n)
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; {
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; n = n >= 0 ? n : -n;
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; int i = 0;
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; while(n >>= 1) {
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; i++;
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; }
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; return i;
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; }
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;
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; ALL: entry
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; ALL: %0 = ashr i32 %abs_n, 1
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; ALL-NEXT: %1 = call i32 @llvm.ctlz.i32(i32 %0, i1 false)
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; ALL-NEXT: %2 = sub i32 32, %1
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; ALL-NEXT: %3 = add i32 %2, 1
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; ALL: %i.0.lcssa = phi i32 [ %2, %while.cond ]
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; ALL: ret i32 %i.0.lcssa
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; Function Attrs: norecurse nounwind readnone uwtable
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define i32 @ctlz(i32 %n) {
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entry:
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%c = icmp sgt i32 %n, 0
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%negn = sub nsw i32 0, %n
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%abs_n = select i1 %c, i32 %n, i32 %negn
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br label %while.cond
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while.cond: ; preds = %while.cond, %entry
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%n.addr.0 = phi i32 [ %abs_n, %entry ], [ %shr, %while.cond ]
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%i.0 = phi i32 [ 0, %entry ], [ %inc, %while.cond ]
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%shr = ashr i32 %n.addr.0, 1
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%tobool = icmp eq i32 %shr, 0
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%inc = add nsw i32 %i.0, 1
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br i1 %tobool, label %while.end, label %while.cond
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while.end: ; preds = %while.cond
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ret i32 %i.0
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}
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; Recognize CTLZ builtin pattern.
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; Here it will replace the loop -
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; assume builtin is always profitable.
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;
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; int ctlz_lshr(int n)
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; {
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; int i = 0;
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; while(n >>= 1) {
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; i++;
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; }
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; return i;
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; }
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;
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; ALL: entry
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; ALL: %0 = lshr i32 %n, 1
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; ALL-NEXT: %1 = call i32 @llvm.ctlz.i32(i32 %0, i1 false)
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; ALL-NEXT: %2 = sub i32 32, %1
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; ALL-NEXT: %3 = add i32 %2, 1
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; ALL: %i.0.lcssa = phi i32 [ %2, %while.cond ]
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; ALL: ret i32 %i.0.lcssa
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; Function Attrs: norecurse nounwind readnone uwtable
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define i32 @ctlz_lshr(i32 %n) {
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entry:
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br label %while.cond
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while.cond: ; preds = %while.cond, %entry
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%n.addr.0 = phi i32 [ %n, %entry ], [ %shr, %while.cond ]
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%i.0 = phi i32 [ 0, %entry ], [ %inc, %while.cond ]
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%shr = lshr i32 %n.addr.0, 1
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%tobool = icmp eq i32 %shr, 0
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%inc = add nsw i32 %i.0, 1
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br i1 %tobool, label %while.end, label %while.cond
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while.end: ; preds = %while.cond
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ret i32 %i.0
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}
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; Recognize CTLZ builtin pattern.
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; Here it will replace the loop -
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; assume builtin is always profitable.
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;
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; int ctlz_add(int n, int i0)
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; {
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; n = n >= 0 ? n : -n;
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; int i = i0;
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; while(n >>= 1) {
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; i++;
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; }
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; return i;
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; }
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;
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; ALL: entry
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; ALL: %0 = ashr i32 %abs_n, 1
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; ALL-NEXT: %1 = call i32 @llvm.ctlz.i32(i32 %0, i1 false)
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; ALL-NEXT: %2 = sub i32 32, %1
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; ALL-NEXT: %3 = add i32 %2, 1
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; ALL-NEXT: %4 = add i32 %2, %i0
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; ALL: %i.0.lcssa = phi i32 [ %4, %while.cond ]
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; ALL: ret i32 %i.0.lcssa
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;
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; Function Attrs: norecurse nounwind readnone uwtable
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define i32 @ctlz_add(i32 %n, i32 %i0) {
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entry:
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%c = icmp sgt i32 %n, 0
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%negn = sub nsw i32 0, %n
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%abs_n = select i1 %c, i32 %n, i32 %negn
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br label %while.cond
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while.cond: ; preds = %while.cond, %entry
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%n.addr.0 = phi i32 [ %abs_n, %entry ], [ %shr, %while.cond ]
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%i.0 = phi i32 [ %i0, %entry ], [ %inc, %while.cond ]
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%shr = ashr i32 %n.addr.0, 1
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%tobool = icmp eq i32 %shr, 0
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%inc = add nsw i32 %i.0, 1
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br i1 %tobool, label %while.end, label %while.cond
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while.end: ; preds = %while.cond
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ret i32 %i.0
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}
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; Recognize CTLZ builtin pattern.
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; Here it will replace the loop -
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; assume builtin is always profitable.
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;
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; int ctlz_add_lshr(int n, int i0)
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; {
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; int i = i0;
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; while(n >>= 1) {
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; i++;
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; }
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; return i;
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; }
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;
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; ALL: entry
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; ALL: %0 = lshr i32 %n, 1
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; ALL-NEXT: %1 = call i32 @llvm.ctlz.i32(i32 %0, i1 false)
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; ALL-NEXT: %2 = sub i32 32, %1
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; ALL-NEXT: %3 = add i32 %2, 1
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; ALL-NEXT: %4 = add i32 %2, %i0
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; ALL: %i.0.lcssa = phi i32 [ %4, %while.cond ]
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; ALL: ret i32 %i.0.lcssa
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;
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; Function Attrs: norecurse nounwind readnone uwtable
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define i32 @ctlz_add_lshr(i32 %n, i32 %i0) {
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entry:
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br label %while.cond
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while.cond: ; preds = %while.cond, %entry
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%n.addr.0 = phi i32 [ %n, %entry ], [ %shr, %while.cond ]
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%i.0 = phi i32 [ %i0, %entry ], [ %inc, %while.cond ]
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%shr = lshr i32 %n.addr.0, 1
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%tobool = icmp eq i32 %shr, 0
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%inc = add nsw i32 %i.0, 1
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br i1 %tobool, label %while.end, label %while.cond
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while.end: ; preds = %while.cond
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ret i32 %i.0
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}
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; Recognize CTLZ builtin pattern.
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; Here it will replace the loop -
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; assume builtin is always profitable.
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;
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; int ctlz_sext(short in)
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; {
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; int n = in;
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; if (in < 0)
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; n = -n;
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; int i = 0;
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; while(n >>= 1) {
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; i++;
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; }
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; return i;
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; }
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;
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; ALL: entry
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; ALL: %0 = ashr i32 %abs_n, 1
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; ALL-NEXT: %1 = call i32 @llvm.ctlz.i32(i32 %0, i1 false)
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; ALL-NEXT: %2 = sub i32 32, %1
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; ALL-NEXT: %3 = add i32 %2, 1
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; ALL: %i.0.lcssa = phi i32 [ %2, %while.cond ]
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; ALL: ret i32 %i.0.lcssa
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; Function Attrs: norecurse nounwind readnone uwtable
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define i32 @ctlz_sext(i16 %in) {
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entry:
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%n = sext i16 %in to i32
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%c = icmp sgt i16 %in, 0
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%negn = sub nsw i32 0, %n
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%abs_n = select i1 %c, i32 %n, i32 %negn
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br label %while.cond
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while.cond: ; preds = %while.cond, %entry
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%n.addr.0 = phi i32 [ %abs_n, %entry ], [ %shr, %while.cond ]
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%i.0 = phi i32 [ 0, %entry ], [ %inc, %while.cond ]
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%shr = ashr i32 %n.addr.0, 1
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%tobool = icmp eq i32 %shr, 0
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%inc = add nsw i32 %i.0, 1
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br i1 %tobool, label %while.end, label %while.cond
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while.end: ; preds = %while.cond
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ret i32 %i.0
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}
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; Recognize CTLZ builtin pattern.
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; Here it will replace the loop -
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; assume builtin is always profitable.
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;
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; int ctlz_sext_lshr(short in)
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; {
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; int i = 0;
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; while(in >>= 1) {
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; i++;
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; }
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; return i;
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; }
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;
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; ALL: entry
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; ALL: %0 = lshr i32 %n, 1
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; ALL-NEXT: %1 = call i32 @llvm.ctlz.i32(i32 %0, i1 false)
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; ALL-NEXT: %2 = sub i32 32, %1
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; ALL-NEXT: %3 = add i32 %2, 1
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; ALL: %i.0.lcssa = phi i32 [ %2, %while.cond ]
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; ALL: ret i32 %i.0.lcssa
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; Function Attrs: norecurse nounwind readnone uwtable
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define i32 @ctlz_sext_lshr(i16 %in) {
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entry:
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%n = sext i16 %in to i32
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br label %while.cond
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while.cond: ; preds = %while.cond, %entry
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%n.addr.0 = phi i32 [ %n, %entry ], [ %shr, %while.cond ]
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%i.0 = phi i32 [ 0, %entry ], [ %inc, %while.cond ]
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%shr = lshr i32 %n.addr.0, 1
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%tobool = icmp eq i32 %shr, 0
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%inc = add nsw i32 %i.0, 1
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br i1 %tobool, label %while.end, label %while.cond
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while.end: ; preds = %while.cond
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ret i32 %i.0
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}
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; This loop contains a volatile store. If x is initially negative,
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; the code will be an infinite loop because the ashr will eventually produce
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; all ones and continue doing so. This prevents the loop from terminating. If
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; we convert this to a countable loop using ctlz that loop will only run 32
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; times. This is different than the infinite number of times of the original.
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define i32 @foo(i32 %x) {
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; LZCNT-LABEL: @foo(
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; LZCNT-NEXT: entry:
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; LZCNT-NEXT: [[V:%.*]] = alloca i8, align 1
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; LZCNT-NEXT: [[TOBOOL4:%.*]] = icmp eq i32 [[X:%.*]], 0
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; LZCNT-NEXT: br i1 [[TOBOOL4]], label [[WHILE_END:%.*]], label [[WHILE_BODY_LR_PH:%.*]]
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; LZCNT: while.body.lr.ph:
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; LZCNT-NEXT: br label [[WHILE_BODY:%.*]]
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; LZCNT: while.body:
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; LZCNT-NEXT: [[CNT_06:%.*]] = phi i32 [ 0, [[WHILE_BODY_LR_PH]] ], [ [[INC:%.*]], [[WHILE_BODY]] ]
|
|
; LZCNT-NEXT: [[X_ADDR_05:%.*]] = phi i32 [ [[X]], [[WHILE_BODY_LR_PH]] ], [ [[SHR:%.*]], [[WHILE_BODY]] ]
|
|
; LZCNT-NEXT: [[SHR]] = ashr i32 [[X_ADDR_05]], 1
|
|
; LZCNT-NEXT: [[INC]] = add i32 [[CNT_06]], 1
|
|
; LZCNT-NEXT: store volatile i8 42, i8* [[V]], align 1
|
|
; LZCNT-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[SHR]], 0
|
|
; LZCNT-NEXT: br i1 [[TOBOOL]], label [[WHILE_COND_WHILE_END_CRIT_EDGE:%.*]], label [[WHILE_BODY]]
|
|
; LZCNT: while.cond.while.end_crit_edge:
|
|
; LZCNT-NEXT: [[SPLIT:%.*]] = phi i32 [ [[INC]], [[WHILE_BODY]] ]
|
|
; LZCNT-NEXT: br label [[WHILE_END]]
|
|
; LZCNT: while.end:
|
|
; LZCNT-NEXT: [[CNT_0_LCSSA:%.*]] = phi i32 [ [[SPLIT]], [[WHILE_COND_WHILE_END_CRIT_EDGE]] ], [ 0, [[ENTRY:%.*]] ]
|
|
; LZCNT-NEXT: ret i32 [[CNT_0_LCSSA]]
|
|
;
|
|
; NOLZCNT-LABEL: @foo(
|
|
; NOLZCNT-NEXT: entry:
|
|
; NOLZCNT-NEXT: [[V:%.*]] = alloca i8, align 1
|
|
; NOLZCNT-NEXT: [[TOBOOL4:%.*]] = icmp eq i32 [[X:%.*]], 0
|
|
; NOLZCNT-NEXT: br i1 [[TOBOOL4]], label [[WHILE_END:%.*]], label [[WHILE_BODY_LR_PH:%.*]]
|
|
; NOLZCNT: while.body.lr.ph:
|
|
; NOLZCNT-NEXT: br label [[WHILE_BODY:%.*]]
|
|
; NOLZCNT: while.body:
|
|
; NOLZCNT-NEXT: [[CNT_06:%.*]] = phi i32 [ 0, [[WHILE_BODY_LR_PH]] ], [ [[INC:%.*]], [[WHILE_BODY]] ]
|
|
; NOLZCNT-NEXT: [[X_ADDR_05:%.*]] = phi i32 [ [[X]], [[WHILE_BODY_LR_PH]] ], [ [[SHR:%.*]], [[WHILE_BODY]] ]
|
|
; NOLZCNT-NEXT: [[SHR]] = ashr i32 [[X_ADDR_05]], 1
|
|
; NOLZCNT-NEXT: [[INC]] = add i32 [[CNT_06]], 1
|
|
; NOLZCNT-NEXT: store volatile i8 42, i8* [[V]], align 1
|
|
; NOLZCNT-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[SHR]], 0
|
|
; NOLZCNT-NEXT: br i1 [[TOBOOL]], label [[WHILE_COND_WHILE_END_CRIT_EDGE:%.*]], label [[WHILE_BODY]]
|
|
; NOLZCNT: while.cond.while.end_crit_edge:
|
|
; NOLZCNT-NEXT: [[SPLIT:%.*]] = phi i32 [ [[INC]], [[WHILE_BODY]] ]
|
|
; NOLZCNT-NEXT: br label [[WHILE_END]]
|
|
; NOLZCNT: while.end:
|
|
; NOLZCNT-NEXT: [[CNT_0_LCSSA:%.*]] = phi i32 [ [[SPLIT]], [[WHILE_COND_WHILE_END_CRIT_EDGE]] ], [ 0, [[ENTRY:%.*]] ]
|
|
; NOLZCNT-NEXT: ret i32 [[CNT_0_LCSSA]]
|
|
;
|
|
entry:
|
|
%v = alloca i8, align 1
|
|
%tobool4 = icmp eq i32 %x, 0
|
|
br i1 %tobool4, label %while.end, label %while.body.lr.ph
|
|
|
|
while.body.lr.ph: ; preds = %entry
|
|
br label %while.body
|
|
|
|
while.body: ; preds = %while.body.lr.ph, %while.body
|
|
%cnt.06 = phi i32 [ 0, %while.body.lr.ph ], [ %inc, %while.body ]
|
|
%x.addr.05 = phi i32 [ %x, %while.body.lr.ph ], [ %shr, %while.body ]
|
|
%shr = ashr i32 %x.addr.05, 1
|
|
%inc = add i32 %cnt.06, 1
|
|
store volatile i8 42, i8* %v, align 1
|
|
%tobool = icmp eq i32 %shr, 0
|
|
br i1 %tobool, label %while.cond.while.end_crit_edge, label %while.body
|
|
|
|
while.cond.while.end_crit_edge: ; preds = %while.body
|
|
%split = phi i32 [ %inc, %while.body ]
|
|
br label %while.end
|
|
|
|
while.end: ; preds = %while.cond.while.end_crit_edge, %entry
|
|
%cnt.0.lcssa = phi i32 [ %split, %while.cond.while.end_crit_edge ], [ 0, %entry ]
|
|
ret i32 %cnt.0.lcssa
|
|
}
|
|
|
|
; We can't easily transform this loop. It returns 1 for an input of both
|
|
; 0 and 1.
|
|
;
|
|
; int ctlz_bad(unsigned n)
|
|
; {
|
|
; int i = 0;
|
|
; do {
|
|
; i++;
|
|
; n >>= 1;
|
|
; } while(n != 0) {
|
|
; return i;
|
|
; }
|
|
;
|
|
; Function Attrs: norecurse nounwind readnone uwtable
|
|
define i32 @ctlz_bad(i32 %n) {
|
|
; ALL-LABEL: @ctlz_bad(
|
|
; ALL-NEXT: entry:
|
|
; ALL-NEXT: br label [[WHILE_COND:%.*]]
|
|
; ALL: while.cond:
|
|
; ALL-NEXT: [[N_ADDR_0:%.*]] = phi i32 [ [[N:%.*]], [[ENTRY:%.*]] ], [ [[SHR:%.*]], [[WHILE_COND]] ]
|
|
; ALL-NEXT: [[I_0:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[INC:%.*]], [[WHILE_COND]] ]
|
|
; ALL-NEXT: [[SHR]] = lshr i32 [[N_ADDR_0]], 1
|
|
; ALL-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[SHR]], 0
|
|
; ALL-NEXT: [[INC]] = add nsw i32 [[I_0]], 1
|
|
; ALL-NEXT: br i1 [[TOBOOL]], label [[WHILE_END:%.*]], label [[WHILE_COND]]
|
|
; ALL: while.end:
|
|
; ALL-NEXT: [[INC_LCSSA:%.*]] = phi i32 [ [[INC]], [[WHILE_COND]] ]
|
|
; ALL-NEXT: ret i32 [[INC_LCSSA]]
|
|
;
|
|
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 = lshr 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 %inc
|
|
}
|