Revert r113439, which relaxed the requirement that loops containing calls cannot be unrolled. After some discussion,

there seems to be a better way to achieve the same effect.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113528 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 2 insertions, 55 deletions

diff --git a/lib/Transforms/Scalar/LoopUnrollPass.cpp b/lib/Transforms/Scalar/LoopUnrollPass.cpp
index 4d23178..7968939 100644
--- a/lib/Transforms/Scalar/LoopUnrollPass.cpp
+++ b/lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -155,10 +155,8 @@ bool LoopUnroll::runOnLoop(Loop *L, LPPassManager &LPM) {
     unsigned LoopSize = ApproximateLoopSize(L, NumCalls);
     DEBUG(dbgs() << "  Loop Size = " << LoopSize << "\n");
     if (NumCalls != 0) {
-      // Even for a loop that contains calls, it can still be profitable to
-      // unroll if the loop is really, REALLY small.
-      DEBUG(dbgs() <<"  Using lower threshold for loop with function calls.\n");
-      CurrentThreshold = OptSizeUnrollThreshold;
+      DEBUG(dbgs() << "  Not unrolling loop with function calls.\n");
+      return false;
     }
     uint64_t Size = (uint64_t)LoopSize*Count;
     if (TripCount != 1 && Size > CurrentThreshold) {
diff --git a/test/Transforms/LoopUnroll/call.ll b/test/Transforms/LoopUnroll/call.ll
deleted file mode 100644
index 5dcb3bc..0000000
--- a/test/Transforms/LoopUnroll/call.ll
+++ /dev/null
@@ -1,51 +0,0 @@
-; RUN: opt < %s -S -loop-unroll | FileCheck %s
-
-@id = internal global i32 0
-@val = internal global [4 x i32] zeroinitializer, align 16
-
-; CHECK: @test
-define i32 @test(i32 %k) nounwind ssp {
-; CHECK-NOT: call i32 @test(i32 %t.06)
-; CHECK: call i32 @test(i32 0)
-; CHECK-NOT: call i32 @test(i32 %t.06)
-; CHECK: call i32 @test(i32 1)
-; CHECK-NOT: call i32 @test(i32 %t.06)
-; CHECK: call i32 @test(i32 2)
-; CHECK-NOT: call i32 @test(i32 %t.06)
-; CHECK: call i32 @test(i32 3)
-; CHECK-NOT: call i32 @test(i32 %t.06)
-
-bb.nph:
-  %0 = load i32* @id, align 4
-  %1 = add nsw i32 %0, 1
-  store i32 %1, i32* @id, align 4
-  %2 = sext i32 %k to i64
-  %3 = getelementptr inbounds [4 x i32]* @val, i64 0, i64 %2
-  store i32 %1, i32* %3, align 4
-  br label %bb
-
-bb:                                               ; preds = %bb2, %bb.nph
-  %indvar = phi i64 [ 0, %bb.nph ], [ %indvar.next, %bb2 ]
-  %scevgep = getelementptr [4 x i32]* @val, i64 0, i64 %indvar
-  %4 = load i32* %scevgep, align 4
-  %5 = icmp eq i32 %4, 0
-  br i1 %5, label %bb1, label %bb2
-
-bb1:                                              ; preds = %bb
-  %t.06 = trunc i64 %indvar to i32
-  %6 = tail call i32 @test(i32 %t.06) nounwind
-  br label %bb2
-
-bb2:                                              ; preds = %bb1, %bb
-  %indvar.next = add i64 %indvar, 1
-  %exitcond = icmp eq i64 %indvar.next, 4
-  br i1 %exitcond, label %bb4, label %bb
-
-bb4:                                              ; preds = %bb2
-  %.pre = load i32* @id, align 4
-  %7 = add nsw i32 %.pre, -1
-  store i32 %7, i32* @id, align 4
-  store i32 0, i32* %3, align 4
-  ret i32 undef
-; CHECK: }
-}