r214512 - Revert r214497: [mips] Defer va_arg expansion to the backend.

[Daniel Sanders]

Author: dsanders
Date: Fri Aug  1 08:26:28 2014
New Revision: 214512

URL: http://llvm.org/viewvc/llvm-project?rev=214512&view=rev
Log:
Revert r214497: [mips] Defer va_arg expansion to the backend.

It appears that the backend does not handle all cases that were handled by clang.
In particular, it does not handle structs as used in
SingleSource/UnitTests/2003-05-07-VarArgs.


Removed:
    cfe/trunk/test/CodeGen/mips-vaarg.c
Modified:
    cfe/trunk/lib/CodeGen/TargetInfo.cpp

Modified: cfe/trunk/lib/CodeGen/TargetInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/TargetInfo.cpp?rev=214512&r1=214511&r2=214512&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/TargetInfo.cpp (original)
+++ cfe/trunk/lib/CodeGen/TargetInfo.cpp Fri Aug  1 08:26:28 2014
@@ -5560,7 +5560,39 @@ void MipsABIInfo::computeInfo(CGFunction
 
 llvm::Value* MipsABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty,
                                     CodeGenFunction &CGF) const {
-  return nullptr;
+  llvm::Type *BP = CGF.Int8PtrTy;
+  llvm::Type *BPP = CGF.Int8PtrPtrTy;
+ 
+  CGBuilderTy &Builder = CGF.Builder;
+  llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP, "ap");
+  llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur");
+  int64_t TypeAlign = getContext().getTypeAlign(Ty) / 8;
+  llvm::Type *PTy = llvm::PointerType::getUnqual(CGF.ConvertType(Ty));
+  llvm::Value *AddrTyped;
+  unsigned PtrWidth = getTarget().getPointerWidth(0);
+  llvm::IntegerType *IntTy = (PtrWidth == 32) ? CGF.Int32Ty : CGF.Int64Ty;
+
+  if (TypeAlign > MinABIStackAlignInBytes) {
+    llvm::Value *AddrAsInt = CGF.Builder.CreatePtrToInt(Addr, IntTy);
+    llvm::Value *Inc = llvm::ConstantInt::get(IntTy, TypeAlign - 1);
+    llvm::Value *Mask = llvm::ConstantInt::get(IntTy, -TypeAlign);
+    llvm::Value *Add = CGF.Builder.CreateAdd(AddrAsInt, Inc);
+    llvm::Value *And = CGF.Builder.CreateAnd(Add, Mask);
+    AddrTyped = CGF.Builder.CreateIntToPtr(And, PTy);
+  }
+  else
+    AddrTyped = Builder.CreateBitCast(Addr, PTy);  
+
+  llvm::Value *AlignedAddr = Builder.CreateBitCast(AddrTyped, BP);
+  TypeAlign = std::max((unsigned)TypeAlign, MinABIStackAlignInBytes);
+  uint64_t Offset =
+    llvm::RoundUpToAlignment(CGF.getContext().getTypeSize(Ty) / 8, TypeAlign);
+  llvm::Value *NextAddr =
+    Builder.CreateGEP(AlignedAddr, llvm::ConstantInt::get(IntTy, Offset),
+                      "ap.next");
+  Builder.CreateStore(NextAddr, VAListAddrAsBPP);
+  
+  return AddrTyped;
 }
 
 bool

Removed: cfe/trunk/test/CodeGen/mips-vaarg.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/mips-vaarg.c?rev=214511&view=auto
==============================================================================
--- cfe/trunk/test/CodeGen/mips-vaarg.c (original)
+++ cfe/trunk/test/CodeGen/mips-vaarg.c (removed)
@@ -1,29 +0,0 @@
-// RUN: %clang -target mips-unknown-linux     -S -o - -emit-llvm %s | FileCheck --check-prefix=ALL --check-prefix=O32 %s
-// RUN: %clang -target mipsel-unknown-linux   -S -o - -emit-llvm %s | FileCheck --check-prefix=ALL --check-prefix=O32 %s
-// RUN: %clang -target mips64-unknown-linux   -S -o - -emit-llvm %s -mabi=n32 | FileCheck --check-prefix=ALL --check-prefix=N32 %s
-// RUN: %clang -target mips64el-unknown-linux -S -o - -emit-llvm %s -mabi=n32 | FileCheck --check-prefix=ALL --check-prefix=N32 %s
-// RUN: %clang -target mips64-unknown-linux   -S -o - -emit-llvm %s -mabi=64  | FileCheck --check-prefix=ALL --check-prefix=N64 %s
-// RUN: %clang -target mips64el-unknown-linux -S -o - -emit-llvm %s -mabi=64  | FileCheck --check-prefix=ALL --check-prefix=N64 %s
-
-int foo (int a, ...)
-{
-    // ALL-LABEL: define i32 @foo(i32 %a, ...)
-
-    __builtin_va_list va;
-    // O32: %va = alloca i8*, align 4
-    // N32: %va = alloca i8*, align 4
-    // N64: %va = alloca i8*, align 8
-
-    __builtin_va_start (va, a);
-    // ALL: %va1 = bitcast i8** %va to i8*
-    // ALL: call void @llvm.va_start(i8* %va1)
-
-    int n = __builtin_va_arg (va, int);
-    // ALL: %{{[0-9]+}} = va_arg i8** %va, i32
-    
-    __builtin_va_end (va);
-    // ALL: %va2 = bitcast i8** %va to i8*
-    // ALL: call void @llvm.va_end(i8* %va2)
-
-    return n;
-}