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