From: Daniel Sanders Date: Thu, 4 Sep 2014 13:28:14 +0000 (+0000) Subject: [mips] Zero-sized structs cannot be ignored in MipsABIInfo::classifyReturnType()... X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3957ae834ef7abf820bf0b42ec5067ce95c491db;p=clang [mips] Zero-sized structs cannot be ignored in MipsABIInfo::classifyReturnType() for O32 Summary: They are returned indirectly which causes the other arguments to move to the next argument slot. With this, utils/ABITest does not discover any failing cases in the first 500 attempts on big/little endian for O32. Previously some of these failed. Also tested N32/N64 little endian (big endian has other known issues) with no issues. Reviewers: atanasyan Reviewed By: atanasyan Subscribers: atanasyan, cfe-commits Differential Revision: http://reviews.llvm.org/D4811 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@217147 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/CodeGen/TargetInfo.cpp b/lib/CodeGen/TargetInfo.cpp index fb3b931ce9..d33d6a09e0 100644 --- a/lib/CodeGen/TargetInfo.cpp +++ b/lib/CodeGen/TargetInfo.cpp @@ -5548,7 +5548,12 @@ MipsABIInfo::returnAggregateInRegs(QualType RetTy, uint64_t Size) const { ABIArgInfo MipsABIInfo::classifyReturnType(QualType RetTy) const { uint64_t Size = getContext().getTypeSize(RetTy); - if (RetTy->isVoidType() || Size == 0) + if (RetTy->isVoidType()) + return ABIArgInfo::getIgnore(); + + // O32 doesn't treat zero-sized structs differently from other structs. + // However, N32/N64 ignores zero sized return values. + if (!IsO32 && Size == 0) return ABIArgInfo::getIgnore(); if (isAggregateTypeForABI(RetTy) || RetTy->isVectorType()) { diff --git a/test/CodeGen/mips-zero-sized-struct.c b/test/CodeGen/mips-zero-sized-struct.c new file mode 100644 index 0000000000..afff3b41d8 --- /dev/null +++ b/test/CodeGen/mips-zero-sized-struct.c @@ -0,0 +1,16 @@ +// RUN: %clang -target mips-unknown-linux-gnu -S -emit-llvm -o - %s | FileCheck -check-prefix=O32 %s +// RUN: %clang -target mipsel-unknown-linux-gnu -S -emit-llvm -o - %s | FileCheck -check-prefix=O32 %s +// RUN: %clang -target mips64-unknown-linux-gnu -S -emit-llvm -o - %s -mabi=n32 | FileCheck -check-prefix=N32 %s +// RUN: %clang -target mips64el-unknown-linux-gnu -S -emit-llvm -o - %s -mabi=n32 | FileCheck -check-prefix=N32 %s +// RUN: %clang -target mips64-unknown-linux-gnu -S -emit-llvm -o - %s | FileCheck -check-prefix=N64 %s +// RUN: %clang -target mips64el-unknown-linux-gnu -S -emit-llvm -o - %s | FileCheck -check-prefix=N64 %s + +// O32: define void @fn28(%struct.T2* noalias sret %agg.result, i8 signext %arg0) +// N32: define void @fn28(i8 signext %arg0) +// N64: define void @fn28(i8 signext %arg0) + +typedef struct T2 { } T2; +T2 T2_retval; +T2 fn28(char arg0) { + return T2_retval; +}