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-rw-r--r--lib/CodeGen/LiveIntervalAnalysis.cpp20
-rw-r--r--lib/CodeGen/RegAllocLinearScan.cpp5
-rw-r--r--lib/CodeGen/SimpleRegisterCoalescing.cpp3
-rw-r--r--test/CodeGen/X86/2008-09-29-ReMatBug.ll85
4 files changed, 105 insertions, 8 deletions
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index bc66321b4a..4ed456bf11 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -819,6 +819,7 @@ bool LiveIntervals::isValNoAvailableAt(const LiveInterval &li, MachineInstr *MI,
/// val# of the specified interval is re-materializable.
bool LiveIntervals::isReMaterializable(const LiveInterval &li,
const VNInfo *ValNo, MachineInstr *MI,
+ SmallVectorImpl<LiveInterval*> &SpillIs,
bool &isLoad) {
if (DisableReMat)
return false;
@@ -855,8 +856,8 @@ bool LiveIntervals::isReMaterializable(const LiveInterval &li,
// If the instruction accesses memory and the memory could be non-constant,
// assume the instruction is not rematerializable.
- for (std::list<MachineMemOperand>::const_iterator I = MI->memoperands_begin(),
- E = MI->memoperands_end(); I != E; ++I) {
+ for (std::list<MachineMemOperand>::const_iterator
+ I = MI->memoperands_begin(), E = MI->memoperands_end(); I != E; ++I){
const MachineMemOperand &MMO = *I;
if (MMO.isVolatile() || MMO.isStore())
return false;
@@ -924,13 +925,21 @@ bool LiveIntervals::isReMaterializable(const LiveInterval &li,
if (!isValNoAvailableAt(ImpLi, MI, UseIdx))
return false;
}
+
+ // If a register operand of the re-materialized instruction is going to
+ // be spilled next, then it's not legal to re-materialize this instruction.
+ for (unsigned i = 0, e = SpillIs.size(); i != e; ++i)
+ if (ImpUse == SpillIs[i]->reg)
+ return false;
}
return true;
}
/// isReMaterializable - Returns true if every definition of MI of every
/// val# of the specified interval is re-materializable.
-bool LiveIntervals::isReMaterializable(const LiveInterval &li, bool &isLoad) {
+bool LiveIntervals::isReMaterializable(const LiveInterval &li,
+ SmallVectorImpl<LiveInterval*> &SpillIs,
+ bool &isLoad) {
isLoad = false;
for (LiveInterval::const_vni_iterator i = li.vni_begin(), e = li.vni_end();
i != e; ++i) {
@@ -944,7 +953,7 @@ bool LiveIntervals::isReMaterializable(const LiveInterval &li, bool &isLoad) {
MachineInstr *ReMatDefMI = getInstructionFromIndex(DefIdx);
bool DefIsLoad = false;
if (!ReMatDefMI ||
- !isReMaterializable(li, VNI, ReMatDefMI, DefIsLoad))
+ !isReMaterializable(li, VNI, ReMatDefMI, SpillIs, DefIsLoad))
return false;
isLoad |= DefIsLoad;
}
@@ -1728,6 +1737,7 @@ addIntervalsForSpillsFast(const LiveInterval &li,
std::vector<LiveInterval*> LiveIntervals::
addIntervalsForSpills(const LiveInterval &li,
+ SmallVectorImpl<LiveInterval*> &SpillIs,
const MachineLoopInfo *loopInfo, VirtRegMap &vrm,
float &SSWeight) {
@@ -1831,7 +1841,7 @@ addIntervalsForSpills(const LiveInterval &li,
MachineInstr *ReMatDefMI = (DefIdx == ~0u)
? 0 : getInstructionFromIndex(DefIdx);
bool dummy;
- if (ReMatDefMI && isReMaterializable(li, VNI, ReMatDefMI, dummy)) {
+ if (ReMatDefMI && isReMaterializable(li, VNI, ReMatDefMI, SpillIs, dummy)) {
// Remember how to remat the def of this val#.
ReMatOrigDefs[VN] = ReMatDefMI;
// Original def may be modified so we have to make a copy here.
diff --git a/lib/CodeGen/RegAllocLinearScan.cpp b/lib/CodeGen/RegAllocLinearScan.cpp
index d834031ae6..7291e12bbe 100644
--- a/lib/CodeGen/RegAllocLinearScan.cpp
+++ b/lib/CodeGen/RegAllocLinearScan.cpp
@@ -879,8 +879,9 @@ void RALinScan::assignRegOrStackSlotAtInterval(LiveInterval* cur)
if (cur->weight != HUGE_VALF && cur->weight <= minWeight) {
DOUT << "\t\t\tspilling(c): " << *cur << '\n';
float SSWeight;
+ SmallVector<LiveInterval*, 8> spillIs;
std::vector<LiveInterval*> added =
- li_->addIntervalsForSpills(*cur, loopInfo, *vrm_, SSWeight);
+ li_->addIntervalsForSpills(*cur, spillIs, loopInfo, *vrm_, SSWeight);
addStackInterval(cur, ls_, li_, SSWeight, *vrm_);
if (added.empty())
return; // Early exit if all spills were folded.
@@ -931,7 +932,7 @@ void RALinScan::assignRegOrStackSlotAtInterval(LiveInterval* cur)
earliestStart = std::min(earliestStart, sli->beginNumber());
float SSWeight;
std::vector<LiveInterval*> newIs =
- li_->addIntervalsForSpills(*sli, loopInfo, *vrm_, SSWeight);
+ li_->addIntervalsForSpills(*sli, spillIs, loopInfo, *vrm_, SSWeight);
addStackInterval(sli, ls_, li_, SSWeight, *vrm_);
std::copy(newIs.begin(), newIs.end(), std::back_inserter(added));
spilled.insert(sli->reg);
diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index bdc37b16b6..86065f069f 100644
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -2361,7 +2361,8 @@ bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) {
LI.weight = HUGE_VALF;
else {
bool isLoad = false;
- if (li_->isReMaterializable(LI, isLoad)) {
+ SmallVector<LiveInterval*, 4> SpillIs;
+ if (li_->isReMaterializable(LI, SpillIs, isLoad)) {
// If all of the definitions of the interval are re-materializable,
// it is a preferred candidate for spilling. If non of the defs are
// loads, then it's potentially very cheap to re-materialize.
diff --git a/test/CodeGen/X86/2008-09-29-ReMatBug.ll b/test/CodeGen/X86/2008-09-29-ReMatBug.ll
new file mode 100644
index 0000000000..d4da01a508
--- /dev/null
+++ b/test/CodeGen/X86/2008-09-29-ReMatBug.ll
@@ -0,0 +1,85 @@
+; RUN: llvm-as < %s | llc -mtriple=i386-apple-darwin -relocation-model=pic -disable-fp-elim
+
+ %struct..0objc_selector = type opaque
+ %struct.NSString = type opaque
+ %struct.XCStringList = type { i32, %struct._XCStringListNode* }
+ %struct._XCStringListNode = type { [3 x i8], [0 x i8], i8 }
+ %struct.__builtin_CFString = type { i32*, i32, i8*, i32 }
+internal constant %struct.__builtin_CFString { i32* getelementptr ([0 x i32]* @__CFConstantStringClassReference, i32 0, i32 0), i32 1992, i8* getelementptr ([3 x i8]* @"\01LC", i32 0, i32 0), i32 2 } ; <%struct.__builtin_CFString*>:0 [#uses=1]
+@__CFConstantStringClassReference = external global [0 x i32] ; <[0 x i32]*> [#uses=1]
+@"\01LC" = internal constant [3 x i8] c"NO\00" ; <[3 x i8]*> [#uses=1]
+@"\01LC1" = internal constant [1 x i8] zeroinitializer ; <[1 x i8]*> [#uses=1]
+@llvm.used1 = appending global [1 x i8*] [ i8* bitcast (%struct.NSString* (%struct.XCStringList*, %struct..0objc_selector*)* @"-[XCStringList stringRepresentation]" to i8*) ], section "llvm.metadata" ; <[1 x i8*]*> [#uses=0]
+
+define %struct.NSString* @"-[XCStringList stringRepresentation]"(%struct.XCStringList* %self, %struct..0objc_selector* %_cmd) nounwind {
+entry:
+ %0 = load i32* null, align 4 ; <i32> [#uses=1]
+ %1 = and i32 %0, 16777215 ; <i32> [#uses=1]
+ %2 = icmp eq i32 %1, 0 ; <i1> [#uses=1]
+ br i1 %2, label %bb44, label %bb4
+
+bb4: ; preds = %entry
+ %3 = load %struct._XCStringListNode** null, align 4 ; <%struct._XCStringListNode*> [#uses=2]
+ %4 = icmp eq %struct._XCStringListNode* %3, null ; <i1> [#uses=1]
+ %5 = bitcast %struct._XCStringListNode* %3 to i32* ; <i32*> [#uses=1]
+ br label %bb37.outer
+
+bb6: ; preds = %bb37
+ br label %bb19
+
+bb19: ; preds = %bb37, %bb6
+ %.rle = phi i32 [ 0, %bb6 ], [ %10, %bb37 ] ; <i32> [#uses=1]
+ %bufptr.0.lcssa = phi i8* [ null, %bb6 ], [ null, %bb37 ] ; <i8*> [#uses=2]
+ %6 = and i32 %.rle, 16777215 ; <i32> [#uses=1]
+ %7 = icmp eq i32 %6, 0 ; <i1> [#uses=1]
+ br i1 %7, label %bb25.split, label %bb37
+
+bb25.split: ; preds = %bb19
+ call void @foo(i8* getelementptr ([1 x i8]* @"\01LC1", i32 0, i32 0)) nounwind nounwind
+ br label %bb35.outer
+
+bb34: ; preds = %bb35, %bb35, %bb35, %bb35
+ %8 = getelementptr i8* %bufptr.0.lcssa, i32 %totalLength.0.ph ; <i8*> [#uses=1]
+ store i8 92, i8* %8, align 1
+ br label %bb35.outer
+
+bb35.outer: ; preds = %bb34, %bb25.split
+ %totalLength.0.ph = add i32 0, %totalLength.1.ph ; <i32> [#uses=2]
+ br label %bb35
+
+bb35: ; preds = %bb35, %bb35.outer
+ %9 = load i8* null, align 1 ; <i8> [#uses=1]
+ switch i8 %9, label %bb35 [
+ i8 0, label %bb37.outer
+ i8 32, label %bb34
+ i8 92, label %bb34
+ i8 34, label %bb34
+ i8 39, label %bb34
+ ]
+
+bb37.outer: ; preds = %bb35, %bb4
+ %totalLength.1.ph = phi i32 [ 0, %bb4 ], [ %totalLength.0.ph, %bb35 ] ; <i32> [#uses=1]
+ %bufptr.1.ph = phi i8* [ null, %bb4 ], [ %bufptr.0.lcssa, %bb35 ] ; <i8*> [#uses=2]
+ br i1 %4, label %bb39.split, label %bb37
+
+bb37: ; preds = %bb37.outer, %bb19
+ %10 = load i32* %5, align 4 ; <i32> [#uses=1]
+ br i1 false, label %bb6, label %bb19
+
+bb39.split: ; preds = %bb37.outer
+ %11 = bitcast i8* null to %struct.NSString* ; <%struct.NSString*> [#uses=2]
+ %12 = icmp eq i8* null, %bufptr.1.ph ; <i1> [#uses=1]
+ br i1 %12, label %bb44, label %bb42
+
+bb42: ; preds = %bb39.split
+ call void @quux(i8* %bufptr.1.ph) nounwind nounwind
+ ret %struct.NSString* %11
+
+bb44: ; preds = %bb39.split, %entry
+ %.0 = phi %struct.NSString* [ bitcast (%struct.__builtin_CFString* @0 to %struct.NSString*), %entry ], [ %11, %bb39.split ] ; <%struct.NSString*> [#uses=1]
+ ret %struct.NSString* %.0
+}
+
+declare void @foo(i8*)
+
+declare void @quux(i8*)
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-23 13:41:28 +0000