begin to legalize i64 sext

2 files changed, 65 insertions, 4 deletions

diff --git a/lib/Transforms/NaCl/ExpandI64.cpp b/lib/Transforms/NaCl/ExpandI64.cpp
index 741afbb4e0..8f4bcbd2f3 100644
--- a/lib/Transforms/NaCl/ExpandI64.cpp
+++ b/lib/Transforms/NaCl/ExpandI64.cpp
@@ -32,12 +32,34 @@
 #include "llvm/Pass.h"
 #include "llvm/Transforms/NaCl.h"
 
+#include "llvm/Support/raw_ostream.h"
+#include <stdio.h>
+#define dump(x) fprintf(stderr, x "\n")
+#define dumpv(x, ...) fprintf(stderr, x "\n", __VA_ARGS__)
+#define dumpIR(value) { \
+  std::string temp; \
+  raw_string_ostream stream(temp); \
+  stream << *(value); \
+  dumpv("%s\n", temp.c_str()); \
+}
+
 using namespace llvm;
 
 namespace {
   // This is a ModulePass because the pass recreates functions in
   // order to expand i64 arguments to pairs of i32s.
   class ExpandI64 : public ModulePass {
+    typedef std::vector<Value*> SplitParts;
+
+    std::map<Value*, SplitParts> Splits; // old i64 value to new insts
+
+    // splits a 64-bit instruction into 32-bit chunks. We do
+    // not yet have the values yet, as they depend on other
+    // splits, so store the parts in Splits, for FinalizeInst.
+    void SplitInst(Instruction *I);
+
+    void FinalizeInst(Instruction *I);
+
   public:
     static char ID;
     ExpandI64() : ModulePass(ID) {
@@ -53,16 +75,52 @@ INITIALIZE_PASS(ExpandI64, "expand-i64",
                 "Expand and lower i64 operations into 32-bit chunks",
                 false, false)
 
-static void ExpandI64Func(Function *Func) {
-}
+//static void ExpandI64Func(Function *Func) {
+//}
+
+void ExpandI64::SplitInst(Instruction *I) {
+dumpv("si1 %d %d", I->getOpcode(), Instruction::SExt);
+  switch (I->getOpcode()) {
+    case Instruction::SExt: {
+      Value *Input = I->getOperand(0);
+      Type *T = Input->getType();
+      assert(T->getIntegerBitWidth() == 32); // FIXME: sext from smaller
+      // x = sext i32 to i64  ==>
+      // xl = x ; test = x < 0 ; xh = test ? -1 : 0
+      Value *Zero  = Constant::getNullValue(T);
+      Value *Ones  = Constant::getAllOnesValue(T);
+
+      Value *Check = CopyDebug(new ICmpInst(I, ICmpInst::ICMP_SLE, Input, Zero), I);
+      Value *High  = CopyDebug(SelectInst::Create(Check, Ones, Zero, "", I), I);
+      SplitParts &Split = Splits[I];
+      Split.push_back(Check);
+      Split.push_back(High);
 
-static void ExpandI64Inst(VAArgInst *Inst) {
+      break;
+    }
+    //default: // FIXME: abort if we hit something we don't support
+  }
 }
 
 bool ExpandI64::runOnModule(Module &M) {
   bool Changed = false;
   DataLayout DL(&M);
-
+  for (Module::iterator Iter = M.begin(), E = M.end(); Iter != E; ) {
+    Function *Func = Iter++;
+    for (Function::iterator BB = Func->begin(), E = Func->end();
+         BB != E;
+         ++BB) {
+      for (BasicBlock::iterator Iter = BB->begin(), E = BB->end();
+           Iter != E; ) {
+        Instruction *I = Iter++;
+        Type *T = I->getType();
+        if (T->isIntegerTy() && T->getIntegerBitWidth() == 64) {
+          Changed = true;
+          SplitInst(I);
+        }
+      }
+    }
+  }
   return Changed;
 }
 
diff --git a/lib/Transforms/NaCl/PNaClABISimplify.cpp b/lib/Transforms/NaCl/PNaClABISimplify.cpp
index 013c03550d..38d8ae0a40 100644
--- a/lib/Transforms/NaCl/PNaClABISimplify.cpp
+++ b/lib/Transforms/NaCl/PNaClABISimplify.cpp
@@ -143,4 +143,7 @@ void llvm::PNaClABISimplifyAddPostOptPasses(PassManager &PM) {
   // created.
   PM.add(createDeadInstEliminationPass());
   PM.add(createDeadCodeEliminationPass());
+
+  PM.add(createExpandI64Pass()); // EMSCRIPTEN // FIXME: move this before the dce stuff here
 }
+