diff options
Diffstat (limited to 'gnu/packages/patches/llvm-9-fix-lpad-miscompilation.patch')
| -rw-r--r-- | gnu/packages/patches/llvm-9-fix-lpad-miscompilation.patch | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/gnu/packages/patches/llvm-9-fix-lpad-miscompilation.patch b/gnu/packages/patches/llvm-9-fix-lpad-miscompilation.patch new file mode 100644 index 0000000000..6cfe07e50a --- /dev/null +++ b/gnu/packages/patches/llvm-9-fix-lpad-miscompilation.patch @@ -0,0 +1,97 @@ +From 011fb5bf8b31316472fccb1a19c91912246df9b2 Mon Sep 17 00:00:00 2001 +From: Reid Kleckner <rnk@google.com> +Date: Sat, 28 Mar 2020 11:03:14 -0700 +Subject: [PATCH] [CodeGen] Fix sinking local values in lpads with phis + +There was already a test case for landingpads to handle this case, but I +had forgotten to consider PHI instructions preceding the EH_LABEL in the +landingpad. + +PR45261 +--- + llvm/lib/CodeGen/SelectionDAG/FastISel.cpp | 17 +++++++++- + llvm/test/CodeGen/X86/sink-local-value.ll | 36 ++++++++++++++++++++++ + 2 files changed, 52 insertions(+), 1 deletion(-) + +diff --git a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp +index 5ac3606dc662..2638b1e8a05c 100644 +--- a/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp ++++ b/llvm/lib/CodeGen/SelectionDAG/FastISel.cpp +@@ -225,6 +225,21 @@ static bool isRegUsedByPhiNodes(unsigned DefReg, + return false; + } + ++static bool isTerminatingEHLabel(MachineBasicBlock *MBB, MachineInstr &MI) { ++ // Ignore non-EH labels. ++ if (!MI.isEHLabel()) ++ return false; ++ ++ // Any EH label outside a landing pad must be for an invoke. Consider it a ++ // terminator. ++ if (!MBB->isEHPad()) ++ return true; ++ ++ // If this is a landingpad, the first non-phi instruction will be an EH_LABEL. ++ // Don't consider that label to be a terminator. ++ return MI.getIterator() != MBB->getFirstNonPHI(); ++} ++ + /// Build a map of instruction orders. Return the first terminator and its + /// order. Consider EH_LABEL instructions to be terminators as well, since local + /// values for phis after invokes must be materialized before the call. +@@ -233,7 +248,7 @@ void FastISel::InstOrderMap::initialize( + unsigned Order = 0; + for (MachineInstr &I : *MBB) { + if (!FirstTerminator && +- (I.isTerminator() || (I.isEHLabel() && &I != &MBB->front()))) { ++ (I.isTerminator() || isTerminatingEHLabel(MBB, I))) { + FirstTerminator = &I; + FirstTerminatorOrder = Order; + } +diff --git a/llvm/test/CodeGen/X86/sink-local-value.ll b/llvm/test/CodeGen/X86/sink-local-value.ll +index b0e511ac1189..f7d861ac9b6c 100644 +--- a/llvm/test/CodeGen/X86/sink-local-value.ll ++++ b/llvm/test/CodeGen/X86/sink-local-value.ll +@@ -145,6 +145,42 @@ try.cont: ; preds = %entry, %lpad + ; CHECK: retl + + ++define i32 @lpad_phi() personality i32 (...)* @__gxx_personality_v0 { ++entry: ++ store i32 42, i32* @sink_across ++ invoke void @may_throw() ++ to label %try.cont unwind label %lpad ++ ++lpad: ; preds = %entry ++ %p = phi i32 [ 11, %entry ] ; Trivial, but -O0 keeps it ++ %0 = landingpad { i8*, i32 } ++ catch i8* null ++ store i32 %p, i32* @sink_across ++ br label %try.cont ++ ++try.cont: ; preds = %entry, %lpad ++ %r.0 = phi i32 [ 13, %entry ], [ 55, %lpad ] ++ ret i32 %r.0 ++} ++ ++; The constant materialization should be *after* the stores to sink_across, but ++; before any EH_LABEL. ++ ++; CHECK-LABEL: lpad_phi: ++; CHECK: movl $42, sink_across ++; CHECK: movl $13, %{{[a-z]*}} ++; CHECK: .Ltmp{{.*}}: ++; CHECK: calll may_throw ++; CHECK: .Ltmp{{.*}}: ++; CHECK: jmp .LBB{{.*}} ++; CHECK: .LBB{{.*}}: # %lpad ++; CHECK-NEXT: .Ltmp{{.*}}: ++; CHECK: movl {{.*}}, sink_across ++; CHECK: movl $55, %{{[a-z]*}} ++; CHECK: .LBB{{.*}}: # %try.cont ++; CHECK: retl ++ ++ + ; Function Attrs: nounwind readnone speculatable + declare void @llvm.dbg.value(metadata, metadata, metadata) #0 + |