[X86] Initialize and Register X86CondBrFoldingPass

To make X86CondBrFoldingPass can be run with --run-pass option, this can test one wrong assertion on analyzeCompare function for SUB32ri when its operand is not imm

Patch by Jianping Chen

Differential Revision: https://reviews.llvm.org/D55412

llvm-svn: 348620

llvm/lib/Target/X86/X86.h

@@ -143,6 +143,7 @@ void initializeWinEHStatePassPass(PassRegistry &);
 void initializeX86AvoidSFBPassPass(PassRegistry &);
 void initializeX86CallFrameOptimizationPass(PassRegistry &);
 void initializeX86CmovConverterPassPass(PassRegistry &);
+void initializeX86CondBrFoldingPassPass(PassRegistry &);
 void initializeX86DomainReassignmentPass(PassRegistry &);
 void initializeX86ExecutionDomainFixPass(PassRegistry &);
 void initializeX86FlagsCopyLoweringPassPass(PassRegistry &);

llvm/lib/Target/X86/X86CondBrFolding.cpp

@@ -62,8 +62,9 @@ STATISTIC(NumFixedCondBrs, "Number of x86 condbr folded");
 namespace {
 class X86CondBrFoldingPass : public MachineFunctionPass {
 public:
-  X86CondBrFoldingPass() : MachineFunctionPass(ID) {}
-
+  X86CondBrFoldingPass() : MachineFunctionPass(ID) {
+    initializeX86CondBrFoldingPassPass(*PassRegistry::getPassRegistry());
+  }
   StringRef getPassName() const override { return "X86 CondBr Folding"; }
 
   bool runOnMachineFunction(MachineFunction &MF) override;
@@ -73,12 +74,13 @@ public:
     AU.addRequired<MachineBranchProbabilityInfo>();
   }
 
-private:
+public:
   static char ID;
 };
+} // namespace
 
 char X86CondBrFoldingPass::ID = 0;
-} // namespace
+INITIALIZE_PASS(X86CondBrFoldingPass, "X86CondBrFolding", "X86CondBrFolding", false, false)
 
 FunctionPass *llvm::createX86CondBrFolding() {
   return new X86CondBrFoldingPass();

llvm/lib/Target/X86/X86TargetMachine.cpp

@@ -78,6 +78,7 @@ extern "C" void LLVMInitializeX86Target() {
   initializeX86AvoidSFBPassPass(PR);
   initializeX86SpeculativeLoadHardeningPassPass(PR);
   initializeX86FlagsCopyLoweringPassPass(PR);
+  initializeX86CondBrFoldingPassPass(PR);
 }
 
 static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) {

llvm/test/CodeGen/X86/test_x86condbr_globaladdr.mir

@@ -0,0 +1,30 @@
+# XFAIL: *
+# RUN: llc -o - %s -mtriple=i686-- -mcpu=ivybridge --run-pass X86CondBrFolding | FileCheck %s
+# Test wrong assertion when meet SUB32ri with global address
+# in X86CondBrFoldingiPass
+--- |
+  @img2buf_normal = external global i32
+  define void @func() { ret void }
+...
+---
+# CHECK: bb.0:
+# CHECK: %2:gr32 = SUB32ri %1, @img2buf_normal, implicit-def $eflags
+
+name: func
+tracksRegLiveness: true
+body: |
+  bb.0:
+    liveins: $edx
+    %1:gr32 = COPY $edx
+    %2:gr32 = MOV32rm %1:gr32, 1, $noreg, 850256, $noreg
+    %3:gr32 = SUB32ri %2:gr32, @img2buf_normal, implicit-def $eflags
+    JE_1 %bb.2, implicit $eflags
+    JMP_1 %bb.3
+
+  bb.2:
+    RET 0, undef $eax
+
+  bb.3:
+    $eax = MOV32rr %3:gr32
+    RET 0, $eax
+...