From e164c180527354acc16c1b9b2c5a5ed4a1e484d4 Mon Sep 17 00:00:00 2001 From: Rafael Espindola Date: Tue, 2 Aug 2011 22:33:37 +0000 Subject: [PATCH] Implements alignment for long long and double types in va_arg on ARM AAPCS. Patch by Jim (Ningjie) Chen. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@136734 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/TargetInfo.cpp | 11 ++++++++++- test/CodeGen/arm-vaarg-align.c | 33 +++++++++++++++++++++++++++++++++ 2 files changed, 43 insertions(+), 1 deletion(-) create mode 100644 test/CodeGen/arm-vaarg-align.c diff --git a/lib/CodeGen/TargetInfo.cpp b/lib/CodeGen/TargetInfo.cpp index 9dbd11cb48..f7bef11fe1 100644 --- a/lib/CodeGen/TargetInfo.cpp +++ b/lib/CodeGen/TargetInfo.cpp @@ -2575,7 +2575,6 @@ ABIArgInfo ARMABIInfo::classifyReturnType(QualType RetTy) const { llvm::Value *ARMABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty, CodeGenFunction &CGF) const { - // FIXME: Need to handle alignment llvm::Type *BP = llvm::Type::getInt8PtrTy(CGF.getLLVMContext()); llvm::Type *BPP = llvm::PointerType::getUnqual(BP); @@ -2583,6 +2582,16 @@ llvm::Value *ARMABIInfo::EmitVAArg(llvm::Value *VAListAddr, QualType Ty, llvm::Value *VAListAddrAsBPP = Builder.CreateBitCast(VAListAddr, BPP, "ap"); llvm::Value *Addr = Builder.CreateLoad(VAListAddrAsBPP, "ap.cur"); + // Handle address alignment for type alignment > 32 bits + uint64_t TyAlign = CGF.getContext().getTypeAlign(Ty) / 8; + if (TyAlign > 4) { + assert((TyAlign & (TyAlign - 1)) == 0 && + "Alignment is not power of 2!"); + llvm::Value *AddrAsInt = Builder.CreatePtrToInt(Addr, CGF.Int32Ty); + AddrAsInt = Builder.CreateAdd(AddrAsInt, Builder.getInt32(TyAlign - 1)); + AddrAsInt = Builder.CreateAnd(AddrAsInt, Builder.getInt32(~(TyAlign - 1))); + Addr = Builder.CreateIntToPtr(AddrAsInt, BP); + } llvm::Type *PTy = llvm::PointerType::getUnqual(CGF.ConvertType(Ty)); llvm::Value *AddrTyped = Builder.CreateBitCast(Addr, PTy); diff --git a/test/CodeGen/arm-vaarg-align.c b/test/CodeGen/arm-vaarg-align.c new file mode 100644 index 0000000000..1187c02291 --- /dev/null +++ b/test/CodeGen/arm-vaarg-align.c @@ -0,0 +1,33 @@ +// RUN: %clang_cc1 -triple arm -target-abi aapcs %s -emit-llvm -o - | FileCheck -check-prefix=AAPCS %s +// RUN: %clang_cc1 -triple arm -target-abi apcs-gnu %s -emit-llvm -o - | FileCheck -check-prefix=APCS-GNU %s +/* + * Check that va_arg accesses stack according to ABI alignment + * long long and double require 8-byte alignment under AAPCS + * however, they only require 4-byte alignment under APCS + */ +long long t1(int i, ...) { + // AAPCS: t1 + // APCS-GNU: t1 + __builtin_va_list ap; + __builtin_va_start(ap, i); + // AAPCS: add i32 %{{.*}} 7 + // AAPCS: and i32 %{{.*}} -8 + // APCS-GNU-NOT: add i32 %{{.*}} 7 + // APCS-GNU-NOT: and i32 %{{.*}} -8 + long long ll = __builtin_va_arg(ap, long long); + __builtin_va_end(ap); + return ll; +} +double t2(int i, ...) { + // AAPCS: t2 + // APCS-GNU: t2 + __builtin_va_list ap; + __builtin_va_start(ap, i); + // AAPCS: add i32 %{{.*}} 7 + // AAPCS: and i32 %{{.*}} -8 + // APCS-GNU-NOT: add i32 %{{.*}} 7 + // APCS-GNU-NOT: and i32 %{{.*}} -8 + double ll = __builtin_va_arg(ap, double); + __builtin_va_end(ap); + return ll; +} -- 2.40.0