LoopUnroll: If we're doing partial unrolling, use the PartialThreshold to limit unrolling.

Otherwise we use the same threshold as for complete unrolling, which is
way too high. This made us unroll any loop smaller than 150 instructions
by 8 times, but only if someone specified -march=core2 or better,
which happens to be the default on darwin.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207940 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 47 insertions, 0 deletions

diff --git a/test/Transforms/LoopUnroll/X86/partial.ll b/test/Transforms/LoopUnroll/X86/partial.ll
index 15867cbea0..75b9c3fb89 100644
--- a/test/Transforms/LoopUnroll/X86/partial.ll
+++ b/test/Transforms/LoopUnroll/X86/partial.ll
@@ -76,5 +76,52 @@ for.end:                                          ; preds = %vector.body
   ret void
 }
 
+define zeroext i16 @test1(i16* nocapture readonly %arr, i32 %n) #0 {
+entry:
+  %cmp25 = icmp eq i32 %n, 0
+  br i1 %cmp25, label %for.end, label %for.body
+
+for.body:                                         ; preds = %entry, %for.body
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
+  %reduction.026 = phi i16 [ %add14, %for.body ], [ 0, %entry ]
+  %arrayidx = getelementptr inbounds i16* %arr, i64 %indvars.iv
+  %0 = load i16* %arrayidx, align 2
+  %add = add i16 %0, %reduction.026
+  %sext = mul i64 %indvars.iv, 12884901888
+  %idxprom3 = ashr exact i64 %sext, 32
+  %arrayidx4 = getelementptr inbounds i16* %arr, i64 %idxprom3
+  %1 = load i16* %arrayidx4, align 2
+  %add7 = add i16 %add, %1
+  %sext28 = mul i64 %indvars.iv, 21474836480
+  %idxprom10 = ashr exact i64 %sext28, 32
+  %arrayidx11 = getelementptr inbounds i16* %arr, i64 %idxprom10
+  %2 = load i16* %arrayidx11, align 2
+  %add14 = add i16 %add7, %2
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %lftr.wideiv = trunc i64 %indvars.iv.next to i32
+  %exitcond = icmp eq i32 %lftr.wideiv, %n
+  br i1 %exitcond, label %for.end, label %for.body
+
+for.end:                                          ; preds = %for.body, %entry
+  %reduction.0.lcssa = phi i16 [ 0, %entry ], [ %add14, %for.body ]
+  ret i16 %reduction.0.lcssa
+
+; This loop is too large to be partially unrolled (size=16)
+
+; CHECK-LABEL: @test1
+; CHECK: br
+; CHECK: br
+; CHECK: br
+; CHECK: br
+; CHECK-NOT: br
+
+; CHECK-NOUNRL-LABEL: @test1
+; CHECK-NOUNRL: br
+; CHECK-NOUNRL: br
+; CHECK-NOUNRL: br
+; CHECK-NOUNRL: br
+; CHECK-NOUNRL-NOT: br
+}
+
 attributes #0 = { nounwind uwtable }