Really fix PR1734. Carefully track which register uses are sub-register uses by

traversing inverse register coalescing map.

llvm-svn: 43118
This commit is contained in:
Evan Cheng 2007-10-18 07:49:59 +00:00
parent 0b18ddf55a
commit e6a41c066a
3 changed files with 128 additions and 14 deletions

View File

@ -37,19 +37,24 @@ namespace llvm {
LiveIntervals *li_;
LiveVariables *lv_;
typedef IndexedMap<unsigned> Reg2RegMap;
Reg2RegMap r2rMap_;
BitVector allocatableRegs_;
DenseMap<const TargetRegisterClass*, BitVector> allocatableRCRegs_;
/// r2rMap_ - Map from register to its representative register.
///
IndexedMap<unsigned> r2rMap_;
/// r2rRevMap_ - Reverse of r2rRevMap_, i.e. Map from register to all
/// the registers it represent.
IndexedMap<std::vector<unsigned> > r2rRevMap_;
/// JoinedLIs - Keep track which register intervals have been coalesced
/// with other intervals.
BitVector JoinedLIs;
/// SubRegIdxes - Keep track of sub-register and sub-indexes.
/// SubRegIdxes - Keep track of sub-register and indexes.
///
std::vector<std::pair<unsigned, unsigned> > SubRegIdxes;
SmallVector<std::pair<unsigned, unsigned>, 32> SubRegIdxes;
public:
static char ID; // Pass identifcation, replacement for typeid
@ -132,10 +137,15 @@ namespace llvm {
bool AdjustCopiesBackFrom(LiveInterval &IntA, LiveInterval &IntB,
MachineInstr *CopyMI);
/// AddSubRegIdxPairs - Recursively mark all the registers represented by the
/// specified register as sub-registers. The recursion level is expected to be
/// shallow.
void AddSubRegIdxPairs(unsigned Reg, unsigned SubIdx);
/// lastRegisterUse - Returns the last use of the specific register between
/// cycles Start and End. It also returns the use operand by reference. It
/// returns NULL if there are no uses.
MachineInstr *lastRegisterUse(unsigned Start, unsigned End, unsigned Reg,
MachineInstr *lastRegisterUse(unsigned Start, unsigned End, unsigned Reg,
MachineOperand *&MOU);
/// findDefOperand - Returns the MachineOperand that is a def of the specific

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@ -57,7 +57,6 @@ namespace {
const PassInfo *llvm::SimpleRegisterCoalescingID = X.getPassInfo();
void SimpleRegisterCoalescing::getAnalysisUsage(AnalysisUsage &AU) const {
//AU.addPreserved<LiveVariables>();
AU.addPreserved<LiveIntervals>();
AU.addPreservedID(PHIEliminationID);
AU.addPreservedID(TwoAddressInstructionPassID);
@ -185,6 +184,17 @@ bool SimpleRegisterCoalescing::AdjustCopiesBackFrom(LiveInterval &IntA, LiveInte
return true;
}
/// AddSubRegIdxPairs - Recursively mark all the registers represented by the
/// specified register as sub-registers. The recursion level is expected to be
/// shallow.
void SimpleRegisterCoalescing::AddSubRegIdxPairs(unsigned Reg, unsigned SubIdx) {
std::vector<unsigned> &JoinedRegs = r2rRevMap_[Reg];
for (unsigned i = 0, e = JoinedRegs.size(); i != e; ++i) {
SubRegIdxes.push_back(std::make_pair(JoinedRegs[i], SubIdx));
AddSubRegIdxPairs(JoinedRegs[i], SubIdx);
}
}
/// JoinCopy - Attempt to join intervals corresponding to SrcReg/DstReg,
/// which are the src/dst of the copy instruction CopyMI. This returns true
/// if the copy was successfully coalesced away, or if it is never possible
@ -459,8 +469,9 @@ bool SimpleRegisterCoalescing::JoinCopy(MachineInstr *CopyMI,
std::swap(repSrcReg, repDstReg);
std::swap(ResSrcInt, ResDstInt);
}
SubRegIdxes.push_back(std::make_pair(DstReg,
CopyMI->getOperand(2).getImm()));
unsigned SubIdx = CopyMI->getOperand(2).getImm();
SubRegIdxes.push_back(std::make_pair(repSrcReg, SubIdx));
AddSubRegIdxPairs(repSrcReg, SubIdx);
}
DOUT << "\n\t\tJoined. Result = "; ResDstInt->print(DOUT, mri_);
@ -470,6 +481,7 @@ bool SimpleRegisterCoalescing::JoinCopy(MachineInstr *CopyMI,
// being merged.
li_->removeInterval(repSrcReg);
r2rMap_[repSrcReg] = repDstReg;
r2rRevMap_[repDstReg].push_back(repSrcReg);
// Finally, delete the copy instruction.
li_->RemoveMachineInstrFromMaps(CopyMI);
@ -1039,7 +1051,7 @@ void SimpleRegisterCoalescing::joinIntervals() {
}
DOUT << "*** Register mapping ***\n";
for (int i = 0, e = r2rMap_.size(); i != e; ++i)
for (unsigned i = 0, e = r2rMap_.size(); i != e; ++i)
if (r2rMap_[i]) {
DOUT << " reg " << i << " -> ";
DEBUG(printRegName(r2rMap_[i]));
@ -1172,9 +1184,12 @@ void SimpleRegisterCoalescing::printRegName(unsigned reg) const {
}
void SimpleRegisterCoalescing::releaseMemory() {
r2rMap_.clear();
JoinedLIs.clear();
SubRegIdxes.clear();
for (unsigned i = 0, e = r2rMap_.size(); i != e; ++i)
r2rRevMap_[i].clear();
r2rRevMap_.clear();
r2rMap_.clear();
JoinedLIs.clear();
SubRegIdxes.clear();
}
static bool isZeroLengthInterval(LiveInterval *li) {
@ -1204,6 +1219,7 @@ bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) {
SSARegMap *RegMap = mf_->getSSARegMap();
r2rMap_.grow(RegMap->getLastVirtReg());
r2rRevMap_.grow(RegMap->getLastVirtReg());
// Join (coalesce) intervals if requested.
if (EnableJoining) {
@ -1214,7 +1230,8 @@ bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) {
DOUT << "\n";
}
// Track coalesced sub-registers.
// Transfer sub-registers info to SSARegMap now that coalescing information
// is complete.
while (!SubRegIdxes.empty()) {
std::pair<unsigned, unsigned> RI = SubRegIdxes.back();
SubRegIdxes.pop_back();

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@ -0,0 +1,87 @@
; RUN: llvm-as < %s | llc -mtriple=x86_64-linux-gnu | grep addb | not grep x
; RUN: llvm-as < %s | llc -mtriple=x86_64-linux-gnu | grep cmpb | not grep x
; PR1734
target triple = "x86_64-unknown-linux-gnu"
%struct.CUMULATIVE_ARGS = type { i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }
%struct.eh_status = type opaque
%struct.emit_status = type { i32, i32, %struct.rtx_def*, %struct.rtx_def*, %struct.sequence_stack*, i32, %struct.location_t, i32, i8*, %struct.rtx_def** }
%struct.expr_status = type { i32, i32, i32, %struct.rtx_def*, %struct.rtx_def*, %struct.rtx_def* }
%struct.function = type { %struct.eh_status*, %struct.expr_status*, %struct.emit_status*, %struct.varasm_status*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.function*, i32, i32, i32, i32, %struct.rtx_def*, %struct.CUMULATIVE_ARGS, %struct.rtx_def*, %struct.rtx_def*, %struct.initial_value_struct*, %struct.rtx_def*, %struct.rtx_def*, %struct.rtx_def*, %struct.rtx_def*, %struct.rtx_def*, %struct.rtx_def*, i8, i32, i64, %struct.tree_node*, %struct.tree_node*, %struct.rtx_def*, %struct.varray_head_tag*, %struct.temp_slot*, i32, %struct.var_refs_queue*, i32, i32, %struct.rtvec_def*, %struct.tree_node*, i32, i32, i32, %struct.machine_function*, i32, i32, i8, i8, %struct.language_function*, %struct.rtx_def*, i32, i32, i32, i32, %struct.location_t, %struct.varray_head_tag*, %struct.tree_node*, %struct.tree_node*, i8, i8, i8 }
%struct.initial_value_struct = type opaque
%struct.lang_decl = type opaque
%struct.language_function = type opaque
%struct.location_t = type { i8*, i32 }
%struct.machine_function = type { %struct.stack_local_entry*, i8*, %struct.rtx_def*, i32, i32, i32, i32, i32 }
%struct.rtunion = type { i8* }
%struct.rtvec_def = type { i32, [1 x %struct.rtx_def*] }
%struct.rtx_def = type { i16, i8, i8, %struct.u }
%struct.sequence_stack = type { %struct.rtx_def*, %struct.rtx_def*, %struct.sequence_stack* }
%struct.stack_local_entry = type opaque
%struct.temp_slot = type opaque
%struct.tree_common = type { %struct.tree_node*, %struct.tree_node*, %union.tree_ann_d*, i8, i8, i8, i8, i8 }
%struct.tree_decl = type { %struct.tree_common, %struct.location_t, i32, %struct.tree_node*, i8, i8, i8, i8, i8, i8, i8, i8, i32, %struct.tree_decl_u1, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.tree_node*, %struct.rtx_def*, i32, %struct.tree_decl_u2, %struct.tree_node*, %struct.tree_node*, i64, %struct.lang_decl* }
%struct.tree_decl_u1 = type { i64 }
%struct.tree_decl_u2 = type { %struct.function* }
%struct.tree_node = type { %struct.tree_decl }
%struct.u = type { [1 x %struct.rtunion] }
%struct.var_refs_queue = type { %struct.rtx_def*, i32, i32, %struct.var_refs_queue* }
%struct.varasm_status = type opaque
%struct.varray_data = type { [1 x i64] }
%struct.varray_head_tag = type { i64, i64, i32, i8*, %struct.varray_data }
%union.tree_ann_d = type opaque
define void @layout_type(%struct.tree_node* %type) {
entry:
%tmp32 = load i32* null, align 8 ; <i32> [#uses=3]
%tmp3435 = trunc i32 %tmp32 to i8 ; <i8> [#uses=1]
%tmp53 = icmp eq %struct.tree_node* null, null ; <i1> [#uses=1]
br i1 %tmp53, label %cond_next57, label %UnifiedReturnBlock
cond_next57: ; preds = %entry
%tmp65 = and i32 %tmp32, 255 ; <i32> [#uses=1]
switch i32 %tmp65, label %UnifiedReturnBlock [
i32 6, label %bb140
i32 7, label %bb140
i32 8, label %bb140
i32 13, label %bb478
]
bb140: ; preds = %cond_next57, %cond_next57, %cond_next57
%tmp219 = load i32* null, align 8 ; <i32> [#uses=1]
%tmp221222 = trunc i32 %tmp219 to i8 ; <i8> [#uses=1]
%tmp223 = icmp eq i8 %tmp221222, 24 ; <i1> [#uses=1]
br i1 %tmp223, label %cond_true226, label %cond_next340
cond_true226: ; preds = %bb140
switch i8 %tmp3435, label %cond_true288 [
i8 6, label %cond_next340
i8 9, label %cond_next340
i8 7, label %cond_next340
i8 8, label %cond_next340
i8 10, label %cond_next340
]
cond_true288: ; preds = %cond_true226
unreachable
cond_next340: ; preds = %cond_true226, %cond_true226, %cond_true226, %cond_true226, %cond_true226, %bb140
ret void
bb478: ; preds = %cond_next57
br i1 false, label %cond_next500, label %cond_true497
cond_true497: ; preds = %bb478
unreachable
cond_next500: ; preds = %bb478
%tmp513 = load i32* null, align 8 ; <i32> [#uses=1]
%tmp545 = and i32 %tmp513, 8192 ; <i32> [#uses=1]
%tmp547 = and i32 %tmp32, -8193 ; <i32> [#uses=1]
%tmp548 = or i32 %tmp547, %tmp545 ; <i32> [#uses=1]
store i32 %tmp548, i32* null, align 8
ret void
UnifiedReturnBlock: ; preds = %cond_next57, %entry
ret void
}