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-rw-r--r--lib/CodeGen/VirtRegMap.cpp37
-rw-r--r--test/CodeGen/X86/2008-10-17-SpillerBug.ll129
2 files changed, 155 insertions, 11 deletions
diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp
index 79857d9..7ce5347 100644
--- a/lib/CodeGen/VirtRegMap.cpp
+++ b/lib/CodeGen/VirtRegMap.cpp
@@ -1342,6 +1342,7 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM) {
}
// Process all of the spilled uses and all non spilled reg references.
+ SmallVector<int, 2> PotentialDeadStoreSlots;
for (unsigned j = 0, e = VirtUseOps.size(); j != e; ++j) {
unsigned i = VirtUseOps[j];
MachineOperand &MO = MI.getOperand(i);
@@ -1446,17 +1447,14 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM) {
if (MI.getOperand(i).isKill() &&
ReuseSlot <= VirtRegMap::MAX_STACK_SLOT) {
- // This was the last use and the spilled value is still available
- // for reuse. That means the spill was unnecessary!
- MachineInstr* DeadStore = MaybeDeadStores[ReuseSlot];
- if (DeadStore) {
- DOUT << "Removed dead store:\t" << *DeadStore;
- InvalidateKills(*DeadStore, RegKills, KillOps);
- VRM.RemoveMachineInstrFromMaps(DeadStore);
- MBB.erase(DeadStore);
- MaybeDeadStores[ReuseSlot] = NULL;
- ++NumDSE;
- }
+
+ // The store of this spilled value is potentially dead, but we
+ // won't know for certain until we've confirmed that the re-use
+ // above is valid, which means waiting until the other operands
+ // are processed. For now we just track the spill slot, we'll
+ // remove it after the other operands are processed if valid.
+
+ PotentialDeadStoreSlots.push_back(ReuseSlot);
}
continue;
} // CanReuse
@@ -1560,6 +1558,23 @@ void LocalSpiller::RewriteMBB(MachineBasicBlock &MBB, VirtRegMap &VRM) {
DOUT << '\t' << *prior(MII);
}
+ // Ok - now we can remove stores that have been confirmed dead.
+ for (unsigned j = 0, e = PotentialDeadStoreSlots.size(); j != e; ++j) {
+ // This was the last use and the spilled value is still available
+ // for reuse. That means the spill was unnecessary!
+ int PDSSlot = PotentialDeadStoreSlots[j];
+ MachineInstr* DeadStore = MaybeDeadStores[PDSSlot];
+ if (DeadStore) {
+ DOUT << "Removed dead store:\t" << *DeadStore;
+ InvalidateKills(*DeadStore, RegKills, KillOps);
+ VRM.RemoveMachineInstrFromMaps(DeadStore);
+ MBB.erase(DeadStore);
+ MaybeDeadStores[PDSSlot] = NULL;
+ ++NumDSE;
+ }
+ }
+
+
DOUT << '\t' << MI;
diff --git a/test/CodeGen/X86/2008-10-17-SpillerBug.ll b/test/CodeGen/X86/2008-10-17-SpillerBug.ll
new file mode 100644
index 0000000..b7abf70
--- /dev/null
+++ b/test/CodeGen/X86/2008-10-17-SpillerBug.ll
@@ -0,0 +1,129 @@
+; RUN: llvm-as < %s | llc -mtriple=x86_64-pc-linux-gnu -regalloc=pbqp -stats |& grep {Number of dead stores elided} | grep 2
+; PR2898
+
+ %struct.BiContextType = type { i16, i8 }
+ %struct.Bitstream = type { i32, i32, i32, i32, i8*, i32 }
+ %struct.DataPartition = type { %struct.Bitstream*, %struct.DecodingEnvironment, i32 (%struct.SyntaxElement*, %struct.ImageParameters*, %struct.DataPartition*)* }
+ %struct.DecRefPicMarking_t = type { i32, i32, i32, i32, i32, %struct.DecRefPicMarking_t* }
+ %struct.DecodingEnvironment = type { i32, i32, i32, i32, i32, i8*, i32* }
+ %struct.ImageParameters = type { i32, i32, i32, i32, i32*, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [16 x [16 x i16]], [6 x [32 x i32]], [16 x [16 x i32]], [4 x [12 x [4 x [4 x i32]]]], [16 x i32], i8**, i32*, i32***, i32**, i32, i32, i32, i32, %struct.Slice*, %struct.Macroblock*, i32, i32, i32, i32, i32, i32, %struct.DecRefPicMarking_t*, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [3 x i32], i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32***, i32***, i32****, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [3 x [2 x i32]], [3 x [2 x i32]], i32, i32, i64, i64, %struct.timeb, %struct.timeb, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }
+ %struct.Macroblock = type { i32, [2 x i32], i32, i32, %struct.Macroblock*, %struct.Macroblock*, i32, [2 x [4 x [4 x [2 x i32]]]], i32, i64, i64, i32, i32, [4 x i8], [4 x i8], i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }
+ %struct.MotionInfoContexts = type { [4 x [11 x %struct.BiContextType]], [2 x [9 x %struct.BiContextType]], [2 x [10 x %struct.BiContextType]], [2 x [6 x %struct.BiContextType]], [4 x %struct.BiContextType], [4 x %struct.BiContextType], [3 x %struct.BiContextType] }
+ %struct.Slice = type { i32, i32, i32, i32, i32, i32, i32, i32, i32, %struct.DataPartition*, %struct.MotionInfoContexts*, %struct.TextureInfoContexts*, i32, i32*, i32*, i32*, i32, i32*, i32*, i32*, i32 (%struct.ImageParameters*, %struct.inp_par*)*, i32, i32, i32, i32 }
+ %struct.SyntaxElement = type { i32, i32, i32, i32, i32, i32, i32, i32, void (i32, i32, i32*, i32*)*, void (%struct.SyntaxElement*, %struct.ImageParameters*, %struct.DecodingEnvironment*)* }
+ %struct.TextureInfoContexts = type { [2 x %struct.BiContextType], [4 x %struct.BiContextType], [3 x [4 x %struct.BiContextType]], [10 x [4 x %struct.BiContextType]], [10 x [15 x %struct.BiContextType]], [10 x [15 x %struct.BiContextType]], [10 x [5 x %struct.BiContextType]], [10 x [5 x %struct.BiContextType]], [10 x [15 x %struct.BiContextType]], [10 x [15 x %struct.BiContextType]] }
+ %struct.inp_par = type { [1000 x i8], [1000 x i8], [1000 x i8], i32, i32, i32, i32, i32, i32, i32, i32 }
+ %struct.timeb = type { i64, i16, i16, i16 }
+
+define i1 @itrans8x8_bb15_bb15_2E_ce(%struct.ImageParameters* %img, i32 %ioff, [8 x [8 x i32]]* %m6, i64, i64, i64, i64, i64, i64, i64, i64, i32 %i.2.reg2mem.0, i32* %.out, i32* %.out1, i32* %.out2, i32* %.out3, i32* %.out4, i32* %.out5, i32* %.out6, i32* %.out7, i32* %.out8, i32* %indvar.next58.out) {
+newFuncRoot:
+ br label %bb15.ce
+
+codeRepl1.exitStub: ; preds = %bb15.ce
+ store i32 %8, i32* %.out
+ store i32 %24, i32* %.out1
+ store i32 %25, i32* %.out2
+ store i32 %26, i32* %.out3
+ store i32 %27, i32* %.out4
+ store i32 %53, i32* %.out5
+ store i32 %55, i32* %.out6
+ store i32 %57, i32* %.out7
+ store i32 %59, i32* %.out8
+ store i32 %indvar.next58, i32* %indvar.next58.out
+ ret i1 true
+
+bb15.bb15_crit_edge.exitStub: ; preds = %bb15.ce
+ store i32 %8, i32* %.out
+ store i32 %24, i32* %.out1
+ store i32 %25, i32* %.out2
+ store i32 %26, i32* %.out3
+ store i32 %27, i32* %.out4
+ store i32 %53, i32* %.out5
+ store i32 %55, i32* %.out6
+ store i32 %57, i32* %.out7
+ store i32 %59, i32* %.out8
+ store i32 %indvar.next58, i32* %indvar.next58.out
+ ret i1 false
+
+bb15.ce: ; preds = %newFuncRoot
+ %8 = add i32 %i.2.reg2mem.0, %ioff ; <i32> [#uses=3]
+ %9 = sext i32 %i.2.reg2mem.0 to i64 ; <i64> [#uses=8]
+ %10 = getelementptr [8 x [8 x i32]]* %m6, i64 0, i64 %9, i64 0 ; <i32*> [#uses=1]
+ %11 = load i32* %10, align 4 ; <i32> [#uses=2]
+ %12 = getelementptr [8 x [8 x i32]]* %m6, i64 0, i64 %9, i64 4 ; <i32*> [#uses=1]
+ %13 = load i32* %12, align 4 ; <i32> [#uses=2]
+ %14 = add i32 %13, %11 ; <i32> [#uses=2]
+ %15 = sub i32 %11, %13 ; <i32> [#uses=2]
+ %16 = getelementptr [8 x [8 x i32]]* %m6, i64 0, i64 %9, i64 2 ; <i32*> [#uses=1]
+ %17 = load i32* %16, align 4 ; <i32> [#uses=2]
+ %18 = ashr i32 %17, 1 ; <i32> [#uses=1]
+ %19 = getelementptr [8 x [8 x i32]]* %m6, i64 0, i64 %9, i64 6 ; <i32*> [#uses=1]
+ %20 = load i32* %19, align 4 ; <i32> [#uses=2]
+ %21 = sub i32 %18, %20 ; <i32> [#uses=2]
+ %22 = ashr i32 %20, 1 ; <i32> [#uses=1]
+ %23 = add i32 %22, %17 ; <i32> [#uses=2]
+ %24 = add i32 %23, %14 ; <i32> [#uses=4]
+ %25 = add i32 %21, %15 ; <i32> [#uses=4]
+ %26 = sub i32 %15, %21 ; <i32> [#uses=4]
+ %27 = sub i32 %14, %23 ; <i32> [#uses=4]
+ %28 = getelementptr [8 x [8 x i32]]* %m6, i64 0, i64 %9, i64 5 ; <i32*> [#uses=1]
+ %29 = load i32* %28, align 4 ; <i32> [#uses=4]
+ %30 = getelementptr [8 x [8 x i32]]* %m6, i64 0, i64 %9, i64 3 ; <i32*> [#uses=1]
+ %31 = load i32* %30, align 4 ; <i32> [#uses=4]
+ %32 = getelementptr [8 x [8 x i32]]* %m6, i64 0, i64 %9, i64 7 ; <i32*> [#uses=1]
+ %33 = load i32* %32, align 4 ; <i32> [#uses=4]
+ %34 = ashr i32 %33, 1 ; <i32> [#uses=1]
+ %35 = sub i32 %29, %31 ; <i32> [#uses=1]
+ %36 = sub i32 %35, %33 ; <i32> [#uses=1]
+ %37 = sub i32 %36, %34 ; <i32> [#uses=2]
+ %38 = getelementptr [8 x [8 x i32]]* %m6, i64 0, i64 %9, i64 1 ; <i32*> [#uses=1]
+ %39 = load i32* %38, align 4 ; <i32> [#uses=4]
+ %40 = ashr i32 %31, 1 ; <i32> [#uses=1]
+ %41 = add i32 %33, %39 ; <i32> [#uses=1]
+ %42 = sub i32 %41, %31 ; <i32> [#uses=1]
+ %43 = sub i32 %42, %40 ; <i32> [#uses=2]
+ %44 = ashr i32 %29, 1 ; <i32> [#uses=1]
+ %45 = sub i32 %33, %39 ; <i32> [#uses=1]
+ %46 = add i32 %45, %29 ; <i32> [#uses=1]
+ %47 = add i32 %46, %44 ; <i32> [#uses=2]
+ %48 = ashr i32 %39, 1 ; <i32> [#uses=1]
+ %49 = add i32 %29, %31 ; <i32> [#uses=1]
+ %50 = add i32 %49, %39 ; <i32> [#uses=1]
+ %51 = add i32 %50, %48 ; <i32> [#uses=2]
+ %52 = ashr i32 %51, 2 ; <i32> [#uses=1]
+ %53 = add i32 %52, %37 ; <i32> [#uses=4]
+ %54 = ashr i32 %37, 2 ; <i32> [#uses=1]
+ %55 = sub i32 %51, %54 ; <i32> [#uses=4]
+ %56 = ashr i32 %47, 2 ; <i32> [#uses=1]
+ %57 = add i32 %56, %43 ; <i32> [#uses=4]
+ %58 = ashr i32 %43, 2 ; <i32> [#uses=1]
+ %59 = sub i32 %58, %47 ; <i32> [#uses=4]
+ %60 = add i32 %55, %24 ; <i32> [#uses=1]
+ %61 = sext i32 %8 to i64 ; <i64> [#uses=8]
+ %62 = getelementptr %struct.ImageParameters* %img, i64 0, i32 27, i64 %0, i64 %61 ; <i32*> [#uses=1]
+ store i32 %60, i32* %62, align 4
+ %63 = add i32 %59, %25 ; <i32> [#uses=1]
+ %64 = getelementptr %struct.ImageParameters* %img, i64 0, i32 27, i64 %1, i64 %61 ; <i32*> [#uses=1]
+ store i32 %63, i32* %64, align 4
+ %65 = add i32 %57, %26 ; <i32> [#uses=1]
+ %66 = getelementptr %struct.ImageParameters* %img, i64 0, i32 27, i64 %2, i64 %61 ; <i32*> [#uses=1]
+ store i32 %65, i32* %66, align 4
+ %67 = add i32 %53, %27 ; <i32> [#uses=1]
+ %68 = getelementptr %struct.ImageParameters* %img, i64 0, i32 27, i64 %3, i64 %61 ; <i32*> [#uses=1]
+ store i32 %67, i32* %68, align 4
+ %69 = sub i32 %27, %53 ; <i32> [#uses=1]
+ %70 = getelementptr %struct.ImageParameters* %img, i64 0, i32 27, i64 %4, i64 %61 ; <i32*> [#uses=1]
+ store i32 %69, i32* %70, align 4
+ %71 = sub i32 %26, %57 ; <i32> [#uses=1]
+ %72 = getelementptr %struct.ImageParameters* %img, i64 0, i32 27, i64 %5, i64 %61 ; <i32*> [#uses=1]
+ store i32 %71, i32* %72, align 4
+ %73 = sub i32 %25, %59 ; <i32> [#uses=1]
+ %74 = getelementptr %struct.ImageParameters* %img, i64 0, i32 27, i64 %6, i64 %61 ; <i32*> [#uses=1]
+ store i32 %73, i32* %74, align 4
+ %75 = sub i32 %24, %55 ; <i32> [#uses=1]
+ %76 = getelementptr %struct.ImageParameters* %img, i64 0, i32 27, i64 %7, i64 %61 ; <i32*> [#uses=1]
+ store i32 %75, i32* %76, align 4
+ %indvar.next58 = add i32 %i.2.reg2mem.0, 1 ; <i32> [#uses=3]
+ %exitcond59 = icmp eq i32 %indvar.next58, 8 ; <i1> [#uses=1]
+ br i1 %exitcond59, label %codeRepl1.exitStub, label %bb15.bb15_crit_edge.exitStub
+}
generated by cgit v1.1 at 2024-09-12 08:38:06 +0000