forked from OSchip/llvm-project
62 lines
2.0 KiB
LLVM
62 lines
2.0 KiB
LLVM
; RUN: opt -S -unroll-runtime -loop-unroll < %s | FileCheck %s
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target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
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;; Check that we don't emit expensive instructions to compute trip
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;; counts when unrolling loops.
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define i32 @test(i64 %v12, i8* %array, i64* %loc) {
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; CHECK-LABEL: @test(
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; CHECK-NOT: udiv
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entry:
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%step = load i64, i64* %loc, !range !0
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br label %loop
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loop: ; preds = %entry, %loop
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%k.015 = phi i64 [ %v15, %loop ], [ %v12, %entry ]
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%v14 = getelementptr inbounds i8, i8* %array, i64 %k.015
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store i8 0, i8* %v14
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%v15 = add nuw nsw i64 %k.015, %step
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%v16 = icmp slt i64 %v15, 8193
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br i1 %v16, label %loop, label %loopexit
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loopexit: ; preds = %loop
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ret i32 0
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}
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;; Though SCEV for loop tripcount contains division,
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;; it shouldn't be considered expensive, since the division already
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;; exists in the code and we don't need to expand it once more.
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;; Thus, it shouldn't prevent us from unrolling the loop.
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define i32 @test2(i64* %loc, i64 %conv7) {
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; CHECK-LABEL: @test2(
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; CHECK: udiv
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; CHECK: udiv
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; CHECK-NOT: udiv
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; CHECK-LABEL: for.body.prol
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entry:
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%rem0 = load i64, i64* %loc, align 8
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%ExpensiveComputation = udiv i64 %rem0, 42 ; <<< Extra computations are added to the trip-count expression
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br label %bb1
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bb1:
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%div11 = udiv i64 %ExpensiveComputation, %conv7
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%cmp.i38 = icmp ugt i64 %div11, 1
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%div12 = select i1 %cmp.i38, i64 %div11, i64 1
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br label %for.body
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for.body:
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%rem1 = phi i64 [ %rem0, %bb1 ], [ %rem2, %for.body ]
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%k1 = phi i64 [ %div12, %bb1 ], [ %dec, %for.body ]
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%mul1 = mul i64 %rem1, 48271
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%rem2 = urem i64 %mul1, 2147483647
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%dec = add i64 %k1, -1
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%cmp = icmp eq i64 %dec, 0
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br i1 %cmp, label %exit, label %for.body
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exit:
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%rem3 = phi i64 [ %rem2, %for.body ]
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store i64 %rem3, i64* %loc, align 8
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ret i32 0
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}
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!0 = !{i64 1, i64 100}
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