91 lines · plain
1; RUN: opt < %s -S -passes=loop-unroll -unroll-max-iteration-count-to-analyze=1000 -unroll-threshold=10 -unroll-max-percent-threshold-boost=200 | FileCheck %s2; RUN: opt < %s -S -passes='require<opt-remark-emit>,loop(loop-unroll-full)' -unroll-max-iteration-count-to-analyze=1000 -unroll-threshold=10 -unroll-max-percent-threshold-boost=200 | FileCheck %s3target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"4 5@unknown_global = internal unnamed_addr global [9 x i32] [i32 0, i32 -1, i32 0, i32 -1, i32 5, i32 -1, i32 0, i32 -1, i32 0], align 166@weak_constant = weak unnamed_addr constant [9 x i32] [i32 0, i32 -1, i32 0, i32 -1, i32 5, i32 -1, i32 0, i32 -1, i32 0], align 167 8; Though @unknown_global is initialized with constant values, we can't consider9; it as a constant, so we shouldn't unroll the loop.10; CHECK-LABEL: @foo11; CHECK: %array_const_idx = getelementptr inbounds [9 x i32], ptr @unknown_global, i64 0, i64 %iv12define i32 @foo(ptr noalias nocapture readonly %src) {13entry:14 br label %loop15 16loop: ; preds = %loop, %entry17 %iv = phi i64 [ 0, %entry ], [ %inc, %loop ]18 %r = phi i32 [ 0, %entry ], [ %add, %loop ]19 %arrayidx = getelementptr inbounds i32, ptr %src, i64 %iv20 %src_element = load i32, ptr %arrayidx, align 421 %array_const_idx = getelementptr inbounds [9 x i32], ptr @unknown_global, i64 0, i64 %iv22 %const_array_element = load i32, ptr %array_const_idx, align 423 %mul = mul nsw i32 %src_element, %const_array_element24 %add = add nsw i32 %mul, %r25 %inc = add nuw nsw i64 %iv, 126 %exitcond86.i = icmp eq i64 %inc, 927 br i1 %exitcond86.i, label %loop.end, label %loop28 29loop.end: ; preds = %loop30 %r.lcssa = phi i32 [ %r, %loop ]31 ret i32 %r.lcssa32}33 34; Similarly, we can't consider 'weak' symbols as a known constant value, so we35; shouldn't unroll the loop.36; CHECK-LABEL: @foo237; CHECK: %array_const_idx = getelementptr inbounds [9 x i32], ptr @weak_constant, i64 0, i64 %iv38define i32 @foo2(ptr noalias nocapture readonly %src) {39entry:40 br label %loop41 42loop: ; preds = %loop, %entry43 %iv = phi i64 [ 0, %entry ], [ %inc, %loop ]44 %r = phi i32 [ 0, %entry ], [ %add, %loop ]45 %arrayidx = getelementptr inbounds i32, ptr %src, i64 %iv46 %src_element = load i32, ptr %arrayidx, align 447 %array_const_idx = getelementptr inbounds [9 x i32], ptr @weak_constant, i64 0, i64 %iv48 %const_array_element = load i32, ptr %array_const_idx, align 449 %mul = mul nsw i32 %src_element, %const_array_element50 %add = add nsw i32 %mul, %r51 %inc = add nuw nsw i64 %iv, 152 %exitcond86.i = icmp eq i64 %inc, 953 br i1 %exitcond86.i, label %loop.end, label %loop54 55loop.end: ; preds = %loop56 %r.lcssa = phi i32 [ %r, %loop ]57 ret i32 %r.lcssa58}59 60; In this case the loaded value is used only to control branch.61; If we missed that, we could've thought that it's unused and unrolling would62; clean up almost entire loop. Make sure that we do not unroll such loop.63; CHECK-LABEL: @foo364; CHECK: br i1 %exitcond, label %loop.end, label %loop.header65define i32 @foo3(ptr noalias nocapture readonly %src) {66entry:67 br label %loop.header68 69loop.header:70 %iv = phi i64 [ 0, %entry ], [ %inc, %loop.latch ]71 %r1 = phi i32 [ 0, %entry ], [ %r3, %loop.latch ]72 %arrayidx = getelementptr inbounds i32, ptr %src, i64 %iv73 %src_element = load i32, ptr %arrayidx, align 474 %cmp = icmp eq i32 0, %src_element75 br i1 %cmp, label %loop.if, label %loop.latch76 77loop.if:78 %r2 = add i32 %r1, 179 br label %loop.latch80 81loop.latch:82 %r3 = phi i32 [%r1, %loop.header], [%r2, %loop.if]83 %inc = add nuw nsw i64 %iv, 184 %exitcond = icmp eq i64 %inc, 985 br i1 %exitcond, label %loop.end, label %loop.header86 87loop.end:88 %r.lcssa = phi i32 [ %r3, %loop.latch ]89 ret i32 %r.lcssa90}91