diff options
| author | Chris Lattner <sabre@nondot.org> | 2011-04-26 17:41:02 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2011-04-26 17:41:02 +0000 |
| commit | 9750acc079409e52f6563636a112a9de50749b30 (patch) | |
| tree | c4de4b907fe534490798165a404b1318159760e6 | |
| parent | a61e73bda5125c28e48b52e573d115370838596b (diff) | |
Improve the bail-out predicate to really only kick in when phi
translation fails. We were bailing out in some cases that would
cause us to miss GVN'ing some non-local cases away.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130206 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/Scalar/GVN.cpp | 3 | ||||
| -rw-r--r-- | test/Transforms/GVN/rle.ll | 23 | ||||
| -rw-r--r-- | test/Transforms/SimplifyCFG/2006-08-03-Crash.ll | 4 |
3 files changed, 26 insertions, 4 deletions
diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp index 15db9ad70a..7c11323ec8 100644 --- a/lib/Transforms/Scalar/GVN.cpp +++ b/lib/Transforms/Scalar/GVN.cpp @@ -1103,7 +1103,8 @@ bool GVN::processNonLocalLoad(LoadInst *LI, // If we had a phi translation failure, we'll have a single entry which is a // clobber in the current block. Reject this early. - if (Deps.size() == 1 && Deps[0].getResult().isClobber()) { + if (Deps.size() == 1 && Deps[0].getResult().isClobber() && + Deps[0].getResult().getInst()->getParent() == LI->getParent()) { DEBUG( dbgs() << "GVN: non-local load "; WriteAsOperand(dbgs(), LI); diff --git a/test/Transforms/GVN/rle.ll b/test/Transforms/GVN/rle.ll index 42363d8bb2..11e207cda0 100644 --- a/test/Transforms/GVN/rle.ll +++ b/test/Transforms/GVN/rle.ll @@ -570,4 +570,27 @@ entry: } +; Cross block partial alias case. +define i32 @load_load_partial_alias_cross_block(i8* %P) nounwind ssp { +entry: + %xx = bitcast i8* %P to i32* + %x1 = load i32* %xx, align 4 + %cmp = icmp eq i32 %x1, 127 + br i1 %cmp, label %land.lhs.true, label %if.end + +land.lhs.true: ; preds = %entry + %arrayidx4 = getelementptr inbounds i8* %P, i64 1 + %tmp5 = load i8* %arrayidx4, align 1 + %conv6 = zext i8 %tmp5 to i32 + ret i32 %conv6 + +if.end: + ret i32 52 +; CHECK: @load_load_partial_alias_cross_block +; CHECK: land.lhs.true: +; CHECK-NOT: load i8 +; CHECK: ret i32 %conv6 +} + + diff --git a/test/Transforms/SimplifyCFG/2006-08-03-Crash.ll b/test/Transforms/SimplifyCFG/2006-08-03-Crash.ll index 2c84c937ae..70fbddfe33 100644 --- a/test/Transforms/SimplifyCFG/2006-08-03-Crash.ll +++ b/test/Transforms/SimplifyCFG/2006-08-03-Crash.ll @@ -1,7 +1,5 @@ -; RUN: opt < %s -gvn -simplifycfg \ -; RUN: -disable-output +; RUN: opt < %s -gvn -simplifycfg -disable-output ; PR867 -; END. target datalayout = "E-p:32:32" target triple = "powerpc-apple-darwin8" |