Revert "Change ordering of blocks as required by SPIRV Spec (#195)" (#197)

This reverts commit 53688bd35ed4c279ec93b7229e3b741b7ab98b2c.

1 files changed, 0 insertions, 38 deletions

diff --git a/lib/SPIRV/SPIRVRegularizeLLVM.cpp b/lib/SPIRV/SPIRVRegularizeLLVM.cpp
index 022d2c1..1631b61 100644
--- a/lib/SPIRV/SPIRVRegularizeLLVM.cpp
+++ b/lib/SPIRV/SPIRVRegularizeLLVM.cpp
@@ -42,10 +42,8 @@
 #include "SPIRVMDBuilder.h"
 #include "SPIRVMDWalker.h"
 
-#include "llvm/ADT/SCCIterator.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/Triple.h"
-#include "llvm/IR/CFG.h"
 #include "llvm/IR/InstVisitor.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IRBuilder.h"
@@ -83,8 +81,6 @@ public:
   void lowerFuncPtr(Function *F, Op OC);
   void lowerFuncPtr(Module *M);
 
-  bool getSwitchCaseOrdering(BasicBlock *BB);
-
   static char ID;
 private:
   Module *M;
@@ -158,22 +154,6 @@ SPIRVRegularizeLLVM::regularize() {
         }
       }
     }
-
-    if (F->getBasicBlockList().size() < 2)

-      continue;

-    // The order of blocks in a function must satisfy the rule

-    // that blocks appear before all blocks they dominate.

-    // We iterate over the SCCs in a graph in post-order

-    for (scc_iterator<Function*> SCCI = scc_begin(F); !SCCI.isAtEnd(); ++SCCI) {

-      const std::vector<BasicBlock *> &NextSCC = *SCCI;

-      assert(!NextSCC.empty());

-      for (const auto &I : NextSCC) {

-        BasicBlock *BB = I;

-        // The order of blocks in switch instruction shouldn't be changed

-        if (!getSwitchCaseOrdering(BB))

-          BB->moveAfter(&F->getEntryBlock());

-      }

-    }
   }
 
   std::string Err;
@@ -225,26 +205,8 @@ SPIRVRegularizeLLVM::lowerFuncPtr(Module* M) {
     lowerFuncPtr(I.first, I.second);
 }
 
-bool
-SPIRVRegularizeLLVM::getSwitchCaseOrdering(BasicBlock *BB) {
-  // The order of the BBs was reversed
-  // We want to restore the original order of switch statement

-  for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) {

-    BasicBlock *Pred = *PI;

-    // Check if we have a case value

-    if (auto SI = dyn_cast<SwitchInst>(Pred->getTerminator())) {

-      BasicBlock* Default = SI->getDefaultDest();

-      if (BB == Default)

-        BB->moveAfter(Pred);

-      else

-        BB->moveBefore(Default);

-      return true;

-    }

-  }
-  return false;
 }
 
-}
 
 INITIALIZE_PASS(SPIRVRegularizeLLVM, "spvregular",
     "Regularize LLVM for SPIR-V", false, false)