[Clang] refactor CodeGenFunction::EmitAsmStmt NFC

[nickdesaulniers]

Summary

Prerequisite to further modifications in D136497.

Basically, there is a large body of code in CodeGenFunction::EmitAsmStmt
for emitting stores of outputs. We want to be able to repeat this logic,
for each destination of a callbr (rather than just the default
destination which is what the code currently does).

Also does some smaller cleanups like whitespace cleanups, and removing
pointless casts.

[nickdesaulniers]

Let me move the asserts, too.

[nickdesaulniers]

• move asserts

[void]

Thanks!

[nickdesaulniers]

• rebase

[nickdesaulniers]

• rebase

[nickdesaulniers]

• rebase, format

[nickdesaulniers]

• rebase

[void]

Still LGTM :-)

[nickdesaulniers]

• rebase

[shafik]

clang/lib/CodeGen/CGStmt.cpp

2405

To be consistent with bugprone-argument-comment

[nickdesaulniers]

• final rebase

[nickdesaulniers]

• fix bugprone-argument-comment as per @shafik

clang/lib/CodeGen/CGStmt.cpp

 #include "clang/AST/Expr.h"
 #include "clang/AST/Stmt.h"
 #include "clang/AST/StmtVisitor.h"
 #include "clang/Basic/Builtins.h"
 #include "clang/Basic/DiagnosticSema.h"
 #include "clang/Basic/PrettyStackTrace.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Basic/TargetInfo.h"
+#include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/IR/Assumptions.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/InlineAsm.h"
 #include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/MDBuilder.h"
 #include "llvm/Support/SaveAndRestore.h"
static void UpdateAsmCallInst(llvm::CallBase &Result, bool HasSideEffect,
   } else {
     for (unsigned i = 0, e = ResultRegTypes.size(); i != e; ++i) {
       llvm::Value *Tmp = CGF.Builder.CreateExtractValue(&Result, i, "asmresult");
       RegResults.push_back(Tmp);
     }
   }
 }
 
+static void
+EmitAsmStores(CodeGenFunction &CGF, const AsmStmt &S,
+              const llvm::ArrayRef<llvm::Value *> RegResults,
+              const llvm::ArrayRef<llvm::Type *> ResultRegTypes,
+              const llvm::ArrayRef<llvm::Type *> ResultTruncRegTypes,
+              const llvm::ArrayRef<LValue> ResultRegDests,
+              const llvm::ArrayRef<QualType> ResultRegQualTys,
+              const llvm::BitVector &ResultTypeRequiresCast,
+              const llvm::BitVector &ResultRegIsFlagReg) {
+  CGBuilderTy &Builder = CGF.Builder;
+  CodeGenModule &CGM = CGF.CGM;
+  llvm::LLVMContext &CTX = CGF.getLLVMContext();
+
+  assert(RegResults.size() == ResultRegTypes.size());
+  assert(RegResults.size() == ResultTruncRegTypes.size());
+  assert(RegResults.size() == ResultRegDests.size());
+  // ResultRegDests can be also populated by addReturnRegisterOutputs() above,
+  // in which case its size may grow.
+  assert(ResultTypeRequiresCast.size() <= ResultRegDests.size());
+  assert(ResultRegIsFlagReg.size() <= ResultRegDests.size());
+
+  for (unsigned i = 0, e = RegResults.size(); i != e; ++i) {
+    llvm::Value *Tmp = RegResults[i];
+    llvm::Type *TruncTy = ResultTruncRegTypes[i];
+
+    if ((i < ResultRegIsFlagReg.size()) && ResultRegIsFlagReg[i]) {
+      // Target must guarantee the Value `Tmp` here is lowered to a boolean
+      // value.
+      llvm::Constant *Two = llvm::ConstantInt::get(Tmp->getType(), 2);
+      llvm::Value *IsBooleanValue =
+          Builder.CreateCmp(llvm::CmpInst::ICMP_ULT, Tmp, Two);
+      llvm::Function *FnAssume = CGM.getIntrinsic(llvm::Intrinsic::assume);
+      Builder.CreateCall(FnAssume, IsBooleanValue);
+    }
+
+    // If the result type of the LLVM IR asm doesn't match the result type of
+    // the expression, do the conversion.
+    if (ResultRegTypes[i] != TruncTy) {
+
+      // Truncate the integer result to the right size, note that TruncTy can be
+      // a pointer.
+      if (TruncTy->isFloatingPointTy())
+        Tmp = Builder.CreateFPTrunc(Tmp, TruncTy);
+      else if (TruncTy->isPointerTy() && Tmp->getType()->isIntegerTy()) {
+        uint64_t ResSize = CGM.getDataLayout().getTypeSizeInBits(TruncTy);
+        Tmp = Builder.CreateTrunc(
+            Tmp, llvm::IntegerType::get(CTX, (unsigned)ResSize));
+        Tmp = Builder.CreateIntToPtr(Tmp, TruncTy);
+      } else if (Tmp->getType()->isPointerTy() && TruncTy->isIntegerTy()) {
+        uint64_t TmpSize =
+            CGM.getDataLayout().getTypeSizeInBits(Tmp->getType());
+        Tmp = Builder.CreatePtrToInt(
+            Tmp, llvm::IntegerType::get(CTX, (unsigned)TmpSize));
+        Tmp = Builder.CreateTrunc(Tmp, TruncTy);
+      } else if (TruncTy->isIntegerTy()) {
+        Tmp = Builder.CreateZExtOrTrunc(Tmp, TruncTy);
+      } else if (TruncTy->isVectorTy()) {
+        Tmp = Builder.CreateBitCast(Tmp, TruncTy);
+      }
+    }
+
+    LValue Dest = ResultRegDests[i];
+    // ResultTypeRequiresCast elements correspond to the first
+    // ResultTypeRequiresCast.size() elements of RegResults.
+    if ((i < ResultTypeRequiresCast.size()) && ResultTypeRequiresCast[i]) {
+      unsigned Size = CGF.getContext().getTypeSize(ResultRegQualTys[i]);
+      Address A =
+          Builder.CreateElementBitCast(Dest.getAddress(CGF), ResultRegTypes[i]);
+      if (CGF.getTargetHooks().isScalarizableAsmOperand(CGF, TruncTy)) {
+        Builder.CreateStore(Tmp, A);
+        continue;
+      }
+
+      QualType Ty =
+          CGF.getContext().getIntTypeForBitwidth(Size, /*Signed=*/false);
+      if (Ty.isNull()) {
+        const Expr *OutExpr = S.getOutputExpr(i);
+        CGM.getDiags().Report(OutExpr->getExprLoc(),
+                              diag::err_store_value_to_reg);
+        return;
+      }
+      Dest = CGF.MakeAddrLValue(A, Ty);
+    }
+    CGF.EmitStoreThroughLValue(RValue::get(Tmp), Dest);
+  }
+}
+
 void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) {
   // Pop all cleanup blocks at the end of the asm statement.
   CodeGenFunction::RunCleanupsScope Cleanups(*this);
 
   // Assemble the final asm string.
   std::string AsmString = S.generateAsmString(getContext());
 
   // Get all the output and input constraints together.
for (unsigned i = 0, e = InOutArgs.size(); i != e; i++) {
     Args.push_back(InOutArgs[i]);
   }
   Constraints += InOutConstraints;
 
   // Labels
   SmallVector<llvm::BasicBlock *, 16> Transfer;
   llvm::BasicBlock *Fallthrough = nullptr;
   bool IsGCCAsmGoto = false;
-  if (const auto *GS =  dyn_cast<GCCAsmStmt>(&S)) {
+  if (const auto *GS = dyn_cast<GCCAsmStmt>(&S)) {
     IsGCCAsmGoto = GS->isAsmGoto();
     if (IsGCCAsmGoto) {
       for (const auto *E : GS->labels()) {
         JumpDest Dest = getJumpDestForLabel(E->getLabel());
         Transfer.push_back(Dest.getBlock());
         if (!Constraints.empty())
           Constraints += ',';
         Constraints += "!i";
void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) {
   llvm::InlineAsm *IA = llvm::InlineAsm::get(
       FTy, AsmString, Constraints, HasSideEffect,
       /* IsAlignStack */ false, AsmDialect, HasUnwindClobber);
   std::vector<llvm::Value*> RegResults;
   if (IsGCCAsmGoto) {
     llvm::CallBrInst *Result =
         Builder.CreateCallBr(IA, Fallthrough, Transfer, Args);
     EmitBlock(Fallthrough);
-    UpdateAsmCallInst(cast<llvm::CallBase>(*Result), HasSideEffect, false,
-                      ReadOnly, ReadNone, InNoMergeAttributedStmt, S,
-                      ResultRegTypes, ArgElemTypes, *this, RegResults);
+    UpdateAsmCallInst(*Result, HasSideEffect, false, ReadOnly, ReadNone,
+                      InNoMergeAttributedStmt, S, ResultRegTypes, ArgElemTypes,
+                      *this, RegResults);
   } else if (HasUnwindClobber) {
     llvm::CallBase *Result = EmitCallOrInvoke(IA, Args, "");
     UpdateAsmCallInst(*Result, HasSideEffect, true, ReadOnly, ReadNone,
                       InNoMergeAttributedStmt, S, ResultRegTypes, ArgElemTypes,
                       *this, RegResults);
   } else {
     llvm::CallInst *Result =
         Builder.CreateCall(IA, Args, getBundlesForFunclet(IA));
-    UpdateAsmCallInst(cast<llvm::CallBase>(*Result), HasSideEffect, false,
-                      ReadOnly, ReadNone, InNoMergeAttributedStmt, S,
-                      ResultRegTypes, ArgElemTypes, *this, RegResults);
-  }
-
-  assert(RegResults.size() == ResultRegTypes.size());
-  assert(RegResults.size() == ResultTruncRegTypes.size());
-  assert(RegResults.size() == ResultRegDests.size());
-  // ResultRegDests can be also populated by addReturnRegisterOutputs() above,
-  // in which case its size may grow.
-  assert(ResultTypeRequiresCast.size() <= ResultRegDests.size());
-  assert(ResultRegIsFlagReg.size() <= ResultRegDests.size());
-  for (unsigned i = 0, e = RegResults.size(); i != e; ++i) {
-    llvm::Value *Tmp = RegResults[i];
-    llvm::Type *TruncTy = ResultTruncRegTypes[i];
-
-    if ((i < ResultRegIsFlagReg.size()) && ResultRegIsFlagReg[i]) {
-      // Target must guarantee the Value `Tmp` here is lowered to a boolean
-      // value.
-      llvm::Constant *Two = llvm::ConstantInt::get(Tmp->getType(), 2);
-      llvm::Value *IsBooleanValue =
-          Builder.CreateCmp(llvm::CmpInst::ICMP_ULT, Tmp, Two);
-      llvm::Function *FnAssume = CGM.getIntrinsic(llvm::Intrinsic::assume);
-      Builder.CreateCall(FnAssume, IsBooleanValue);
-    }
-
-    // If the result type of the LLVM IR asm doesn't match the result type of
-    // the expression, do the conversion.
-    if (ResultRegTypes[i] != ResultTruncRegTypes[i]) {
-
-      // Truncate the integer result to the right size, note that TruncTy can be
-      // a pointer.
-      if (TruncTy->isFloatingPointTy())
-        Tmp = Builder.CreateFPTrunc(Tmp, TruncTy);
-      else if (TruncTy->isPointerTy() && Tmp->getType()->isIntegerTy()) {
-        uint64_t ResSize = CGM.getDataLayout().getTypeSizeInBits(TruncTy);
-        Tmp = Builder.CreateTrunc(Tmp,
-                   llvm::IntegerType::get(getLLVMContext(), (unsigned)ResSize));
-        Tmp = Builder.CreateIntToPtr(Tmp, TruncTy);
-      } else if (Tmp->getType()->isPointerTy() && TruncTy->isIntegerTy()) {
-        uint64_t TmpSize =CGM.getDataLayout().getTypeSizeInBits(Tmp->getType());
-        Tmp = Builder.CreatePtrToInt(Tmp,
-                   llvm::IntegerType::get(getLLVMContext(), (unsigned)TmpSize));
-        Tmp = Builder.CreateTrunc(Tmp, TruncTy);
-      } else if (TruncTy->isIntegerTy()) {
-        Tmp = Builder.CreateZExtOrTrunc(Tmp, TruncTy);
-      } else if (TruncTy->isVectorTy()) {
-        Tmp = Builder.CreateBitCast(Tmp, TruncTy);
-      }
-    }
-
-    LValue Dest = ResultRegDests[i];
-    // ResultTypeRequiresCast elements correspond to the first
-    // ResultTypeRequiresCast.size() elements of RegResults.
-    if ((i < ResultTypeRequiresCast.size()) && ResultTypeRequiresCast[i]) {
-      unsigned Size = getContext().getTypeSize(ResultRegQualTys[i]);
-      Address A = Builder.CreateElementBitCast(Dest.getAddress(*this),
-                                               ResultRegTypes[i]);
-      if (getTargetHooks().isScalarizableAsmOperand(*this, TruncTy)) {
-        Builder.CreateStore(Tmp, A);
-        continue;
-      }
+    UpdateAsmCallInst(*Result, HasSideEffect, false, ReadOnly, ReadNone,
+                      InNoMergeAttributedStmt, S, ResultRegTypes, ArgElemTypes,
+                      *this, RegResults);
 
-      QualType Ty = getContext().getIntTypeForBitwidth(Size, /*Signed*/ false);
-      if (Ty.isNull()) {
-        const Expr *OutExpr = S.getOutputExpr(i);
-        CGM.getDiags().Report(OutExpr->getExprLoc(),
-                              diag::err_store_value_to_reg);
-        return;
-      }
-      Dest = MakeAddrLValue(A, Ty);
-    }
-    EmitStoreThroughLValue(RValue::get(Tmp), Dest);
-  }
+  EmitAsmStores(*this, S, RegResults, ResultRegTypes, ResultTruncRegTypes,
+                ResultRegDests, ResultRegQualTys, ResultTypeRequiresCast,
+                ResultRegIsFlagReg);
 }
 
 LValue CodeGenFunction::InitCapturedStruct(const CapturedStmt &S) {
   const RecordDecl *RD = S.getCapturedRecordDecl();
   QualType RecordTy = getContext().getRecordType(RD);
 
   // Initialize the captured struct.
   LValue SlotLV =