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-rw-r--r--lib/CodeGen/StackSlotColoring.cpp68
-rw-r--r--test/CodeGen/SystemZ/spill-01.ll75
2 files changed, 117 insertions, 26 deletions
diff --git a/lib/CodeGen/StackSlotColoring.cpp b/lib/CodeGen/StackSlotColoring.cpp
index 9a9b8897ee..e1b63680e0 100644
--- a/lib/CodeGen/StackSlotColoring.cpp
+++ b/lib/CodeGen/StackSlotColoring.cpp
@@ -53,8 +53,11 @@ namespace {
// SSIntervals - Spill slot intervals.
std::vector<LiveInterval*> SSIntervals;
- // SSRefs - Keep a list of frame index references for each spill slot.
- SmallVector<SmallVector<MachineInstr*, 8>, 16> SSRefs;
+ // SSRefs - Keep a list of MachineMemOperands for each spill slot.
+ // MachineMemOperands can be shared between instructions, so we need
+ // to be careful that renames like [FI0, FI1] -> [FI1, FI2] do not
+ // become FI0 -> FI1 -> FI2.
+ SmallVector<SmallVector<MachineMemOperand *, 8>, 16> SSRefs;
// OrigAlignments - Alignments of stack objects before coloring.
SmallVector<unsigned, 16> OrigAlignments;
@@ -103,7 +106,7 @@ namespace {
bool OverlapWithAssignments(LiveInterval *li, int Color) const;
int ColorSlot(LiveInterval *li);
bool ColorSlots(MachineFunction &MF);
- void RewriteInstruction(MachineInstr *MI, int OldFI, int NewFI,
+ void RewriteInstruction(MachineInstr *MI, SmallVector<int, 16> &SlotMapping,
MachineFunction &MF);
bool RemoveDeadStores(MachineBasicBlock* MBB);
};
@@ -155,7 +158,18 @@ void StackSlotColoring::ScanForSpillSlotRefs(MachineFunction &MF) {
LiveInterval &li = LS->getInterval(FI);
if (!MI->isDebugValue())
li.weight += LiveIntervals::getSpillWeight(false, true, Freq);
- SSRefs[FI].push_back(MI);
+ }
+ for (MachineInstr::mmo_iterator MMOI = MI->memoperands_begin(),
+ EE = MI->memoperands_end(); MMOI != EE; ++MMOI) {
+ MachineMemOperand *MMO = *MMOI;
+ if (const Value *V = MMO->getValue()) {
+ if (const FixedStackPseudoSourceValue *FSV =
+ dyn_cast<FixedStackPseudoSourceValue>(V)) {
+ int FI = FSV->getFrameIndex();
+ if (FI >= 0)
+ SSRefs[FI].push_back(MMO);
+ }
+ }
}
}
}
@@ -291,15 +305,26 @@ bool StackSlotColoring::ColorSlots(MachineFunction &MF) {
if (!Changed)
return false;
- // Rewrite all MO_FrameIndex operands.
+ // Rewrite all MachineMemOperands.
for (unsigned SS = 0, SE = SSRefs.size(); SS != SE; ++SS) {
int NewFI = SlotMapping[SS];
if (NewFI == -1 || (NewFI == (int)SS))
continue;
- SmallVectorImpl<MachineInstr*> &RefMIs = SSRefs[SS];
- for (unsigned i = 0, e = RefMIs.size(); i != e; ++i)
- RewriteInstruction(RefMIs[i], SS, NewFI, MF);
+ const Value *NewSV = PseudoSourceValue::getFixedStack(NewFI);
+ SmallVectorImpl<MachineMemOperand *> &RefMMOs = SSRefs[SS];
+ for (unsigned i = 0, e = RefMMOs.size(); i != e; ++i)
+ RefMMOs[i]->setValue(NewSV);
+ }
+
+ // Rewrite all MO_FrameIndex operands. Look for dead stores.
+ for (MachineFunction::iterator MBBI = MF.begin(), E = MF.end();
+ MBBI != E; ++MBBI) {
+ MachineBasicBlock *MBB = &*MBBI;
+ for (MachineBasicBlock::iterator MII = MBB->begin(), EE = MBB->end();
+ MII != EE; ++MII)
+ RewriteInstruction(MII, SlotMapping, MF);
+ RemoveDeadStores(MBB);
}
// Delete unused stack slots.
@@ -314,28 +339,24 @@ bool StackSlotColoring::ColorSlots(MachineFunction &MF) {
/// RewriteInstruction - Rewrite specified instruction by replacing references
/// to old frame index with new one.
-void StackSlotColoring::RewriteInstruction(MachineInstr *MI, int OldFI,
- int NewFI, MachineFunction &MF) {
+void StackSlotColoring::RewriteInstruction(MachineInstr *MI,
+ SmallVector<int, 16> &SlotMapping,
+ MachineFunction &MF) {
// Update the operands.
for (unsigned i = 0, ee = MI->getNumOperands(); i != ee; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (!MO.isFI())
continue;
- int FI = MO.getIndex();
- if (FI != OldFI)
+ int OldFI = MO.getIndex();
+ if (OldFI < 0)
+ continue;
+ int NewFI = SlotMapping[OldFI];
+ if (NewFI == -1 || NewFI == OldFI)
continue;
MO.setIndex(NewFI);
}
- // Update the memory references. This changes the MachineMemOperands
- // directly. They may be in use by multiple instructions, however all
- // instructions using OldFI are being rewritten to use NewFI.
- const Value *OldSV = PseudoSourceValue::getFixedStack(OldFI);
- const Value *NewSV = PseudoSourceValue::getFixedStack(NewFI);
- for (MachineInstr::mmo_iterator I = MI->memoperands_begin(),
- E = MI->memoperands_end(); I != E; ++I)
- if ((*I)->getValue() == OldSV)
- (*I)->setValue(NewSV);
+ // The MachineMemOperands have already been updated.
}
@@ -429,10 +450,5 @@ bool StackSlotColoring::runOnMachineFunction(MachineFunction &MF) {
Assignments[i].clear();
Assignments.clear();
- if (Changed) {
- for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I)
- Changed |= RemoveDeadStores(I);
- }
-
return Changed;
}
diff --git a/test/CodeGen/SystemZ/spill-01.ll b/test/CodeGen/SystemZ/spill-01.ll
index a5e48eefcc..b2d9fe7be4 100644
--- a/test/CodeGen/SystemZ/spill-01.ll
+++ b/test/CodeGen/SystemZ/spill-01.ll
@@ -381,3 +381,78 @@ define void @f9() {
ret void
}
+
+; This showed a problem with the way stack coloring updated instructions.
+; The copy from %val9 to %newval8 can be done using an MVC, which then
+; has two frame index operands. Stack coloring chose a valid renumbering
+; [FI0, FI1] -> [FI1, FI2], but applied it in the form FI0 -> FI1 -> FI2,
+; so that both operands ended up being the same.
+define void @f10() {
+; CHECK: f10:
+; CHECK: lgrl [[REG:%r[0-9]+]], h9
+; CHECK: stg [[REG]], [[VAL9:[0-9]+]](%r15)
+; CHECK: brasl %r14, foo@PLT
+; CHECK: brasl %r14, foo@PLT
+; CHECK: mvc [[NEWVAL8:[0-9]+]](8,%r15), [[VAL9]](%r15)
+; CHECK: brasl %r14, foo@PLT
+; CHECK: lg [[REG:%r[0-9]+]], [[NEWVAL8]](%r15)
+; CHECK: stgrl [[REG]], h8
+; CHECK: br %r14
+entry:
+ %val0 = load volatile i64 *@h0
+ %val1 = load volatile i64 *@h1
+ %val2 = load volatile i64 *@h2
+ %val3 = load volatile i64 *@h3
+ %val4 = load volatile i64 *@h4
+ %val5 = load volatile i64 *@h5
+ %val6 = load volatile i64 *@h6
+ %val7 = load volatile i64 *@h7
+ %val8 = load volatile i64 *@h8
+ %val9 = load volatile i64 *@h9
+
+ call void @foo()
+
+ store volatile i64 %val0, i64 *@h0
+ store volatile i64 %val1, i64 *@h1
+ store volatile i64 %val2, i64 *@h2
+ store volatile i64 %val3, i64 *@h3
+ store volatile i64 %val4, i64 *@h4
+ store volatile i64 %val5, i64 *@h5
+ store volatile i64 %val6, i64 *@h6
+ store volatile i64 %val7, i64 *@h7
+
+ %check = load volatile i64 *@h0
+ %cond = icmp eq i64 %check, 0
+ br i1 %cond, label %skip, label %fallthru
+
+fallthru:
+ call void @foo()
+
+ store volatile i64 %val0, i64 *@h0
+ store volatile i64 %val1, i64 *@h1
+ store volatile i64 %val2, i64 *@h2
+ store volatile i64 %val3, i64 *@h3
+ store volatile i64 %val4, i64 *@h4
+ store volatile i64 %val5, i64 *@h5
+ store volatile i64 %val6, i64 *@h6
+ store volatile i64 %val7, i64 *@h7
+ store volatile i64 %val8, i64 *@h8
+ br label %skip
+
+skip:
+ %newval8 = phi i64 [ %val8, %entry ], [ %val9, %fallthru ]
+ call void @foo()
+
+ store volatile i64 %val0, i64 *@h0
+ store volatile i64 %val1, i64 *@h1
+ store volatile i64 %val2, i64 *@h2
+ store volatile i64 %val3, i64 *@h3
+ store volatile i64 %val4, i64 *@h4
+ store volatile i64 %val5, i64 *@h5
+ store volatile i64 %val6, i64 *@h6
+ store volatile i64 %val7, i64 *@h7
+ store volatile i64 %newval8, i64 *@h8
+ store volatile i64 %val9, i64 *@h9
+
+ ret void
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-29 07:56:06 +0000