RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2025-02-18 11:20:03 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

If converter was being too cute. It look for root BBs (which don't have

Browse Source 
successors) and use inverse depth first search to traverse the BBs. However
that doesn't work when the CFG has infinite loops. Simply do a linear
traversal of all BBs work just fine.

rdar://9344645

llvm-svn: 130324
This commit is contained in:
Evan Cheng 2011-04-27 19:32:43 +00:00
parent d96c818dd2
commit fa34d31aa4
2 changed files with 62 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
lib/CodeGen/IfConversion.cpp
View File

@ -27,7 +27,6 @@
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/STLExtras.h"
@ -146,10 +145,6 @@ namespace {
: BBI(b), Kind(k), NeedSubsumption(s), NumDups(d), NumDups2(d2) {}
};
/// Roots - Basic blocks that do not have successors. These are the starting
/// points of Graph traversal.
std::vector<MachineBasicBlock*> Roots;
/// BBAnalysis - Results of if-conversion feasibility analysis indexed by
/// basic block number.
std::vector<BBInfo> BBAnalysis;
@ -287,11 +282,6 @@ bool IfConverter::runOnMachineFunction(MachineFunction &MF) {
MF.RenumberBlocks();
BBAnalysis.resize(MF.getNumBlockIDs());
// Look for root nodes, i.e. blocks without successors.
for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I)
if (I->succ_empty())
Roots.push_back(I);
std::vector<IfcvtToken*> Tokens;
MadeChange = false;
unsigned NumIfCvts = NumSimple + NumSimpleFalse + NumTriangle +
@ -406,7 +396,6 @@ bool IfConverter::runOnMachineFunction(MachineFunction &MF) {
}
Tokens.clear();
Roots.clear();
BBAnalysis.clear();
if (MadeChange && IfCvtBranchFold) {
@ -924,13 +913,9 @@ IfConverter::BBInfo &IfConverter::AnalyzeBlock(MachineBasicBlock *BB,
/// candidates.
void IfConverter::AnalyzeBlocks(MachineFunction &MF,
std::vector<IfcvtToken*> &Tokens) {
std::set<MachineBasicBlock*> Visited;
for (unsigned i = 0, e = Roots.size(); i != e; ++i) {
for (idf_ext_iterator<MachineBasicBlock*> I=idf_ext_begin(Roots[i],Visited),
E = idf_ext_end(Roots[i], Visited); I != E; ++I) {
MachineBasicBlock *BB = *I;
AnalyzeBlock(BB, Tokens);
}
for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) {
MachineBasicBlock *BB = I;
AnalyzeBlock(BB, Tokens);
}
// Sort to favor more complex ifcvt scheme.

59
test/CodeGen/ARM/2011-04-27-IfCvtBug.ll Normal file
View File

@ -0,0 +1,59 @@
; RUN: llc < %s -mtriple=thumbv7-apple-ios
; If converter was being too cute. It look for root BBs (which don't have
; successors) and use inverse depth first search to traverse the BBs. However
; that doesn't work when the CFG has infinite loops. Simply do a linear
; traversal of all BBs work just fine.
; rdar://9344645
%struct.hc = type { i32, i32, i32, i32 }
define i32 @t(i32 %type) optsize {
entry:
br i1 undef, label %if.then, label %if.else
if.then:
unreachable
if.else:
br i1 undef, label %if.then15, label %if.else18
if.then15:
unreachable
if.else18:
switch i32 %type, label %if.else173 [
i32 3, label %if.then115
i32 1, label %if.then102
]
if.then102:
br i1 undef, label %cond.true10.i, label %t.exit
cond.true10.i:
br label %t.exit
t.exit:
unreachable
if.then115:
br i1 undef, label %if.else163, label %if.else145
if.else145:
%call150 = call fastcc %struct.hc* @foo(%struct.hc* undef, i32 34865152) optsize
br label %while.body172
if.else163:
%call168 = call fastcc %struct.hc* @foo(%struct.hc* undef, i32 34078720) optsize
br label %while.body172
while.body172:
br label %while.body172
if.else173:
ret i32 -1
}
declare hidden fastcc %struct.hc* @foo(%struct.hc* nocapture, i32) nounwind optsize