Updated names and created BranchRange.cpp

Author: SandroMaglione

BranchRange.cpp

@@ -0,0 +1,51 @@
+#include "llvm/Pass.h"
+#include "llvm/IR/Function.h"
+#include "llvm/Support/raw_ostream.h"
+
+#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/Transforms/IPO/PassManagerBuilder.h"
+
+using namespace llvm;
+
+namespace
+{
+    struct HppsBranchRange : public FunctionPass
+    {
+        static char ID;
+        HppsBranchRange() : FunctionPass(ID) {}
+
+        // Run over a single function
+        bool runOnFunction(Function &Func) override
+        {
+            // Run over all basic blocks in the function
+            for (BasicBlock &BB : Func)
+            {
+                // Print out the name of the basic block if it has one, and then the
+                // number of instructions that it contains
+                errs() << "Basic block (name=" << BB.getName() << ") has "
+                       << BB.size() << " instructions.\n";
+
+                // Run over all instructions in the basic block
+                for (Instruction &I : BB)
+                {
+                    // The next statement works since operator<<(ostream&,...)
+                    // is overloaded for Instruction&
+                    errs() << I << "\n";
+                }
+            }
+
+            errs().write_escaped(Func.getName()) << '\n';
+            return false;
+        }
+    }; // end of struct HppsBranchRange
+} // end of anonymous namespace
+
+char HppsBranchRange::ID = 0;
+static RegisterPass<HppsBranchRange> X("branch-range", "Branch Range Pass",
+                                       false /* Only looks at CFG */,
+                                       false /* Analysis Pass */);
+
+static RegisterStandardPasses Y(
+    PassManagerBuilder::EP_EarlyAsPossible,
+    [](const PassManagerBuilder &Builder,
+       legacy::PassManagerBase &PM) { PM.add(new HppsBranchRange()); });

ConstantRange.cpp

@@ -16,10 +16,10 @@ using namespace llvm;
 namespace
 {
 
-  struct Hpps : public FunctionPass
+  struct HppsConstantRange : public FunctionPass
   {
     static char ID;
-    Hpps() : FunctionPass(ID) {}
+    HppsConstantRange() : FunctionPass(ID) {}
 
     // Run over a single function (main)
     bool runOnFunction(Function &Func) override
@@ -293,13 +293,13 @@ namespace
   }; // namespace
 } // end of anonymous namespace
 
-char Hpps::ID = 0;
-static RegisterPass<Hpps> X("const-range", "Constant Range Pass",
+char HppsConstantRange::ID = 0;
+static RegisterPass<HppsConstantRange> X("const-range", "Constant Range Pass",
                             false /* Only looks at CFG */,
                             false /* Analysis Pass */);
 
 static RegisterStandardPasses Y(PassManagerBuilder::EP_EarlyAsPossible,
                                 [](const PassManagerBuilder &Builder,
                                    legacy::PassManagerBase &PM) {
-                                  PM.add(new Hpps());
+                                  PM.add(new HppsConstantRange());
                                 });

src/bra/README.md

@@ -0,0 +1,6 @@
+## Generate SSA from using -mem2reg
+- Create file `bra.c` in directory **~/Public/project/code**
+- Open directory **~/Public/project/llvm-project/build/bin**
+- Run command `./clang -c -O0 -emit-llvm ../../../code/bra.c -o bra.bc -Xclang -disable-O0-optnone` to generate `bra.bc` (bitecode)
+- Run command `./llvm-dis bra.bc -o=bra.ll` to generate `bra.ll` (IR)
+- Run command `./opt -mem2reg -S bra.ll -o bra-opt.ll` to generate SSA form using `-mem2reg` (Remove instructions and add PHI nodes1)

src/bra/bra/bra-opt.ll

@@ -0,0 +1,31 @@
+; ModuleID = 'bra.ll'
+source_filename = "../../../code/bra.c"
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; Function Attrs: noinline nounwind uwtable
+define dso_local i32 @main() #0 {
+entry:
+  %cmp = icmp slt i32 0, 100
+  br i1 %cmp, label %if.then, label %if.else
+
+if.then:                                          ; preds = %entry
+  %add = add nsw i32 0, 1
+  br label %if.end
+
+if.else:                                          ; preds = %entry
+  %sub = sub nsw i32 0, 1
+  br label %if.end
+
+if.end:                                           ; preds = %if.else, %if.then
+  %k.0 = phi i32 [ %add, %if.then ], [ %sub, %if.else ]
+  ret i32 %k.0
+}
+
+attributes #0 = { noinline nounwind uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.module.flags = !{!0}
+!llvm.ident = !{!1}
+
+!0 = !{i32 1, !"wchar_size", i32 4}
+!1 = !{!"clang version 7.1.0 "}

src/bra/bra/bra.c

@@ -0,0 +1,16 @@
+#include <stdio.h>
+
+int main() {
+  int k = 0;
+  int j = k;
+
+  if (k < 100) {
+    k = k + 1;
+    j = k;
+  } else {
+    j = j - 1;
+    k = j;
+  }
+
+  return k;
+}