Revert "[flang] Integrate the option -flang-experimental-integer-overflow into -fno-wrapv" (#113901)

Reverts llvm/llvm-project#110063 due to the performance regression on
503.bwaves_r in SPEC2017.

6 files changed, 17 insertions, 11 deletions

diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
index 5da5236..94d3d11 100644
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -1350,6 +1350,12 @@ bool CompilerInvocation::createFromArgs(
     invoc.loweringOpts.setNoPPCNativeVecElemOrder(true);
   }
 
+  // -flang-experimental-integer-overflow
+  if (args.hasArg(
+          clang::driver::options::OPT_flang_experimental_integer_overflow)) {
+    invoc.loweringOpts.setNSWOnLoopVarInc(true);
+  }
+
   // Preserve all the remark options requested, i.e. -Rpass, -Rpass-missed or
   // -Rpass-analysis. This will be used later when processing and outputting the
   // remarks generated by LLVM in ExecuteCompilerInvocation.cpp.
diff --git a/flang/lib/Frontend/FrontendActions.cpp b/flang/lib/Frontend/FrontendActions.cpp
index 3ea2423..f2e460f 100644
--- a/flang/lib/Frontend/FrontendActions.cpp
+++ b/flang/lib/Frontend/FrontendActions.cpp
@@ -828,8 +828,8 @@ void CodeGenAction::generateLLVMIR() {
     config.VScaleMax = vsr->second;
   }
 
-  if (ci.getInvocation().getLoweringOpts().getIntegerWrapAround())
-    config.NSWOnLoopVarInc = false;
+  if (ci.getInvocation().getLoweringOpts().getNSWOnLoopVarInc())
+    config.NSWOnLoopVarInc = true;
 
   // Create the pass pipeline
   fir::createMLIRToLLVMPassPipeline(pm, config, getCurrentFile());
diff --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp
index a3bd1ac..877fe122 100644
--- a/flang/lib/Lower/Bridge.cpp
+++ b/flang/lib/Lower/Bridge.cpp
@@ -2271,7 +2271,7 @@ private:
     assert(!incrementLoopNestInfo.empty() && "empty loop nest");
     mlir::Location loc = toLocation();
     mlir::arith::IntegerOverflowFlags flags{};
-    if (!getLoweringOptions().getIntegerWrapAround())
+    if (getLoweringOptions().getNSWOnLoopVarInc())
       flags = bitEnumSet(flags, mlir::arith::IntegerOverflowFlags::nsw);
     auto iofAttr = mlir::arith::IntegerOverflowFlagsAttr::get(
         builder->getContext(), flags);
diff --git a/flang/lib/Lower/IO.cpp b/flang/lib/Lower/IO.cpp
index b534c81..1894b0c 100644
--- a/flang/lib/Lower/IO.cpp
+++ b/flang/lib/Lower/IO.cpp
@@ -929,7 +929,7 @@ static void genIoLoop(Fortran::lower::AbstractConverter &converter,
   fir::FirOpBuilder &builder = converter.getFirOpBuilder();
   mlir::Location loc = converter.getCurrentLocation();
   mlir::arith::IntegerOverflowFlags flags{};
-  if (!converter.getLoweringOptions().getIntegerWrapAround())
+  if (converter.getLoweringOptions().getNSWOnLoopVarInc())
     flags = bitEnumSet(flags, mlir::arith::IntegerOverflowFlags::nsw);
   auto iofAttr =
       mlir::arith::IntegerOverflowFlagsAttr::get(builder.getContext(), flags);
diff --git a/flang/lib/Optimizer/Passes/Pipelines.cpp b/flang/lib/Optimizer/Passes/Pipelines.cpp
index 091b7c4..3c139f7 100644
--- a/flang/lib/Optimizer/Passes/Pipelines.cpp
+++ b/flang/lib/Optimizer/Passes/Pipelines.cpp
@@ -35,11 +35,11 @@ void addCanonicalizerPassWithoutRegionSimplification(mlir::OpPassManager &pm) {
 void addCfgConversionPass(mlir::PassManager &pm,
                           const MLIRToLLVMPassPipelineConfig &config) {
   if (config.NSWOnLoopVarInc)
+    addNestedPassToAllTopLevelOperationsConditionally(
+        pm, disableCfgConversion, fir::createCFGConversionPassWithNSW);
+  else
     addNestedPassToAllTopLevelOperationsConditionally(pm, disableCfgConversion,
                                                       fir::createCFGConversion);
-  else
-    addNestedPassToAllTopLevelOperationsConditionally(
-        pm, disableCfgConversion, fir::createCFGConversionPassWithoutNSW);
 }
 
 void addAVC(mlir::PassManager &pm, const llvm::OptimizationLevel &optLevel) {
diff --git a/flang/lib/Optimizer/Transforms/ControlFlowConverter.cpp b/flang/lib/Optimizer/Transforms/ControlFlowConverter.cpp
index 411bf7f..3b79d6d 100644
--- a/flang/lib/Optimizer/Transforms/ControlFlowConverter.cpp
+++ b/flang/lib/Optimizer/Transforms/ControlFlowConverter.cpp
@@ -332,6 +332,8 @@ class CfgConversion : public fir::impl::CFGConversionBase<CfgConversion> {
 public:
   using CFGConversionBase<CfgConversion>::CFGConversionBase;
 
+  CfgConversion(bool setNSW) { this->setNSW = setNSW; }
+
   void runOnOperation() override {
     auto *context = &this->getContext();
     mlir::RewritePatternSet patterns(context);
@@ -364,8 +366,6 @@ void fir::populateCfgConversionRewrites(mlir::RewritePatternSet &patterns,
       patterns.getContext(), forceLoopToExecuteOnce, setNSW);
 }
 
-std::unique_ptr<mlir::Pass> fir::createCFGConversionPassWithoutNSW() {
-  fir::CFGConversionOptions options;
-  options.setNSW = false;
-  return fir::createCFGConversion(options);
+std::unique_ptr<mlir::Pass> fir::createCFGConversionPassWithNSW() {
+  return std::make_unique<CfgConversion>(true);
 }