diff options
| -rw-r--r-- | lib/Transforms/Scalar/GVN.cpp | 13 | ||||
| -rw-r--r-- | test/Transforms/GVN/load-pre-licm.ll | 39 |
2 files changed, 39 insertions, 13 deletions
diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp index de99c3f8b6..f1272d4956 100644 --- a/lib/Transforms/Scalar/GVN.cpp +++ b/lib/Transforms/Scalar/GVN.cpp @@ -1545,19 +1545,6 @@ bool GVN::processNonLocalLoad(LoadInst *LI, assert(TmpBB); LoadBB = TmpBB; - // If we have a repl set with LI itself in it, this means we have a loop where - // at least one of the values is LI. Since this means that we won't be able - // to eliminate LI even if we insert uses in the other predecessors, we will - // end up increasing code size. Reject this by scanning for LI. - for (unsigned i = 0, e = ValuesPerBlock.size(); i != e; ++i) { - if (ValuesPerBlock[i].isSimpleValue() && - ValuesPerBlock[i].getSimpleValue() == LI) { - // Skip cases where LI is the only definition, even for EnableFullLoadPRE. - if (!EnableFullLoadPRE || e == 1) - return false; - } - } - // FIXME: It is extremely unclear what this loop is doing, other than // artificially restricting loadpre. if (isSinglePred) { diff --git a/test/Transforms/GVN/load-pre-licm.ll b/test/Transforms/GVN/load-pre-licm.ll new file mode 100644 index 0000000000..bbcc6223f5 --- /dev/null +++ b/test/Transforms/GVN/load-pre-licm.ll @@ -0,0 +1,39 @@ +; RUN: opt -S -gvn < %s | FileCheck %s +target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-n8:16:32" +target triple = "i386-apple-darwin11.0.0" + +@sortlist = external global [5001 x i32], align 4 + +define void @Bubble() nounwind noinline { +; CHECK: entry: +; CHECK-NEXT: %tmp7.pre = load i32 +entry: + br label %while.body5 + +; CHECK: while.body5: +; CHECK: %tmp7 = phi i32 +; CHECK-NOT: %tmp7 = load i32 +while.body5: + %indvar = phi i32 [ 0, %entry ], [ %tmp6, %if.end ] + %tmp5 = add i32 %indvar, 2 + %arrayidx9 = getelementptr [5001 x i32]* @sortlist, i32 0, i32 %tmp5 + %tmp6 = add i32 %indvar, 1 + %arrayidx = getelementptr [5001 x i32]* @sortlist, i32 0, i32 %tmp6 + %tmp7 = load i32* %arrayidx, align 4 + %tmp10 = load i32* %arrayidx9, align 4 + %cmp11 = icmp sgt i32 %tmp7, %tmp10 + br i1 %cmp11, label %if.then, label %if.end + +; CHECK: if.then: +if.then: + store i32 %tmp10, i32* %arrayidx, align 4 + store i32 %tmp7, i32* %arrayidx9, align 4 + br label %if.end + +if.end: + %exitcond = icmp eq i32 %tmp6, 100 + br i1 %exitcond, label %while.end.loopexit, label %while.body5 + +while.end.loopexit: + ret void +} |