From db8771af286bc84267e7b5bd17eab51cd4ea552f Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Fri, 2 Apr 2010 02:21:24 +0000 Subject: [PATCH] After trivial coalescing, the MI being visited may have become a copy. Avoid adding it to CSE hash table since copies aren't being considered for CSE and they may be deleted. rdar://7819990 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100170 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/MachineCSE.cpp | 6 +- .../PowerPC/2010-04-01-MachineCSEBug.ll | 70 +++++++++++++++++++ 2 files changed, 75 insertions(+), 1 deletion(-) create mode 100644 test/CodeGen/PowerPC/2010-04-01-MachineCSEBug.ll diff --git a/lib/CodeGen/MachineCSE.cpp b/lib/CodeGen/MachineCSE.cpp index fc9dea8e827..597d51d4f37 100644 --- a/lib/CodeGen/MachineCSE.cpp +++ b/lib/CodeGen/MachineCSE.cpp @@ -294,8 +294,12 @@ bool MachineCSE::ProcessBlock(MachineDomTreeNode *Node) { bool FoundCSE = VNT.count(MI); if (!FoundCSE) { // Look for trivial copy coalescing opportunities. - if (PerformTrivialCoalescing(MI, MBB)) + if (PerformTrivialCoalescing(MI, MBB)) { + // After coalescing MI itself may become a copy. + if (isCopy(MI, TII)) + continue; FoundCSE = VNT.count(MI); + } } // FIXME: commute commutable instructions? diff --git a/test/CodeGen/PowerPC/2010-04-01-MachineCSEBug.ll b/test/CodeGen/PowerPC/2010-04-01-MachineCSEBug.ll new file mode 100644 index 00000000000..8fd05502ba8 --- /dev/null +++ b/test/CodeGen/PowerPC/2010-04-01-MachineCSEBug.ll @@ -0,0 +1,70 @@ +; RUN: llc < %s -mtriple=powerpc-apple-darwin10.0 +; rdar://7819990 + +%0 = type { i32 } +%1 = type { i64 } +%struct.Buffer = type { [1024 x i8], i64, i64, i64 } +%struct.InStream = type { %struct.Buffer, %0, %1, i32*, %struct.InStreamMethods* } +%struct.InStreamMethods = type { void (%struct.InStream*, i8*, i32)*, void (%struct.InStream*, i64)*, i64 (%struct.InStream*)*, void (%struct.InStream*)* } + +define i64 @t(%struct.InStream* %is) nounwind optsize ssp { +entry: + br i1 undef, label %is_read_byte.exit, label %bb.i + +bb.i: ; preds = %entry + br label %is_read_byte.exit + +is_read_byte.exit: ; preds = %bb.i, %entry + br i1 undef, label %is_read_byte.exit22, label %bb.i21 + +bb.i21: ; preds = %is_read_byte.exit + unreachable + +is_read_byte.exit22: ; preds = %is_read_byte.exit + br i1 undef, label %is_read_byte.exit19, label %bb.i18 + +bb.i18: ; preds = %is_read_byte.exit22 + br label %is_read_byte.exit19 + +is_read_byte.exit19: ; preds = %bb.i18, %is_read_byte.exit22 + br i1 undef, label %is_read_byte.exit16, label %bb.i15 + +bb.i15: ; preds = %is_read_byte.exit19 + unreachable + +is_read_byte.exit16: ; preds = %is_read_byte.exit19 + %0 = shl i64 undef, 32 ; [#uses=1] + br i1 undef, label %is_read_byte.exit13, label %bb.i12 + +bb.i12: ; preds = %is_read_byte.exit16 + unreachable + +is_read_byte.exit13: ; preds = %is_read_byte.exit16 + %1 = shl i64 undef, 24 ; [#uses=1] + br i1 undef, label %is_read_byte.exit10, label %bb.i9 + +bb.i9: ; preds = %is_read_byte.exit13 + unreachable + +is_read_byte.exit10: ; preds = %is_read_byte.exit13 + %2 = shl i64 undef, 16 ; [#uses=1] + br i1 undef, label %is_read_byte.exit7, label %bb.i6 + +bb.i6: ; preds = %is_read_byte.exit10 + br label %is_read_byte.exit7 + +is_read_byte.exit7: ; preds = %bb.i6, %is_read_byte.exit10 + %3 = shl i64 undef, 8 ; [#uses=1] + br i1 undef, label %is_read_byte.exit4, label %bb.i3 + +bb.i3: ; preds = %is_read_byte.exit7 + unreachable + +is_read_byte.exit4: ; preds = %is_read_byte.exit7 + %4 = or i64 0, %0 ; [#uses=1] + %5 = or i64 %4, %1 ; [#uses=1] + %6 = or i64 %5, %2 ; [#uses=1] + %7 = or i64 %6, %3 ; [#uses=1] + %8 = or i64 %7, 0 ; [#uses=1] + ret i64 %8 +}