75 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			75 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			LLVM
		
	
	
	
; RUN: opt < %s -loop-vectorize -prefer-predicate-over-epilogue=predicate-dont-vectorize -force-vector-width=4 -S | FileCheck %s
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; Check that a counting-down loop which has no primary induction variable
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; is vectorized with preferred predication.
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; CHECK-LABEL: vector.body:
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; CHECK-LABEL: middle.block:
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; CHECK-NEXT:    br i1 true,
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target datalayout = "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64"
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define dso_local void @foo(i8* noalias nocapture readonly %A, i8* noalias nocapture readonly %B, i8* noalias nocapture %C, i32 %N) {
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entry:
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  %cmp6 = icmp eq i32 %N, 0
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  br i1 %cmp6, label %while.end, label %while.body.preheader
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while.body.preheader:
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  br label %while.body
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while.body:
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  %N.addr.010 = phi i32 [ %dec, %while.body ], [ %N, %while.body.preheader ]
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  %C.addr.09 = phi i8* [ %incdec.ptr4, %while.body ], [ %C, %while.body.preheader ]
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  %B.addr.08 = phi i8* [ %incdec.ptr1, %while.body ], [ %B, %while.body.preheader ]
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  %A.addr.07 = phi i8* [ %incdec.ptr, %while.body ], [ %A, %while.body.preheader ]
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  %incdec.ptr = getelementptr inbounds i8, i8* %A.addr.07, i32 1
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  %0 = load i8, i8* %A.addr.07, align 1
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  %incdec.ptr1 = getelementptr inbounds i8, i8* %B.addr.08, i32 1
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  %1 = load i8, i8* %B.addr.08, align 1
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  %add = add i8 %1, %0
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  %incdec.ptr4 = getelementptr inbounds i8, i8* %C.addr.09, i32 1
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  store i8 %add, i8* %C.addr.09, align 1
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  %dec = add i32 %N.addr.010, -1
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  %cmp = icmp eq i32 %dec, 0
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  br i1 %cmp, label %while.end.loopexit, label %while.body
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while.end.loopexit:
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  br label %while.end
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while.end:
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  ret void
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}
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; Make sure a loop is successfully vectorized with fold-tail when the backedge
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; taken count is constant and used inside the loop. Issue revealed by D76992.
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;
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define void @reuse_const_btc(i8* %A) optsize {
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; CHECK-LABEL: @reuse_const_btc
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; CHECK: {{%.*}} = icmp ule <4 x i32> {{%.*}}, <i32 13, i32 13, i32 13, i32 13>
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; CHECK: {{%.*}} = select <4 x i1> {{%.*}}, <4 x i32> <i32 12, i32 12, i32 12, i32 12>, <4 x i32> <i32 13, i32 13, i32 13, i32 13>
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;
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entry:
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  br label %loop
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loop:
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  %riv = phi i32 [ 13, %entry ], [ %rivMinus1, %merge ]
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  %sub = sub nuw nsw i32 20, %riv
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  %arrayidx = getelementptr inbounds i8, i8* %A, i32 %sub
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  %cond0 = icmp eq i32 %riv, 7
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  br i1 %cond0, label %then, label %else
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then:
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  br label %merge
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else:
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  br label %merge
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merge:
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  %blend = phi i32 [ 13, %then ], [ 12, %else ]
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  %trunc = trunc i32 %blend to i8
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  store i8 %trunc, i8* %arrayidx, align 1
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  %rivMinus1 = add nuw nsw i32 %riv, -1
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  %cond = icmp eq i32 %riv, 0
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  br i1 %cond, label %exit, label %loop
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exit:
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  ret void
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}
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