Author: James Clarke Date: 2020-01-14T11:17:19Z New Revision: 3d6c492d7a9830a1a39b85dfa215743581d52715
URL: https://github.com/llvm/llvm-project/commit/3d6c492d7a9830a1a39b85dfa215743581d52715 DIFF: https://github.com/llvm/llvm-project/commit/3d6c492d7a9830a1a39b85dfa215743581d52715.diff LOG: [RISCV] Fix ILP32D lowering for double+double/double+int return types Summary: Previously, since these aggregates are > 2*XLen, Clang would think they were being returned indirectly and thus would decrease the number of available GPRs available by 1. For long argument lists this could lead to a struct argument incorrectly being passed indirectly. Reviewers: asb, lenary Reviewed By: asb, lenary Subscribers: luismarques, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, lenary, s.egerton, pzheng, sameer.abuasal, cfe-commits Tags: #clang Differential Revision: https://reviews.llvm.org/D69590 Added: Modified: clang/lib/CodeGen/TargetInfo.cpp clang/test/CodeGen/riscv32-ilp32d-abi.c Removed: ################################################################################ diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp index 7068fa0fcc69..dd6597f154bb 100644 --- a/clang/lib/CodeGen/TargetInfo.cpp +++ b/clang/lib/CodeGen/TargetInfo.cpp @@ -9377,11 +9377,21 @@ void RISCVABIInfo::computeInfo(CGFunctionInfo &FI) const { FI.getReturnInfo() = classifyReturnType(RetTy); // IsRetIndirect is true if classifyArgumentType indicated the value should - // be passed indirect or if the type size is greater than 2*xlen. e.g. fp128 - // is passed direct in LLVM IR, relying on the backend lowering code to - // rewrite the argument list and pass indirectly on RV32. - bool IsRetIndirect = FI.getReturnInfo().getKind() == ABIArgInfo::Indirect || - getContext().getTypeSize(RetTy) > (2 * XLen); + // be passed indirect, or if the type size is a scalar greater than 2*XLen + // and not a complex type with elements <= FLen. e.g. fp128 is passed direct + // in LLVM IR, relying on the backend lowering code to rewrite the argument + // list and pass indirectly on RV32. + bool IsRetIndirect = FI.getReturnInfo().getKind() == ABIArgInfo::Indirect; + if (!IsRetIndirect && RetTy->isScalarType() && + getContext().getTypeSize(RetTy) > (2 * XLen)) { + if (RetTy->isComplexType() && FLen) { + QualType EltTy = RetTy->getAs<ComplexType>()->getElementType(); + IsRetIndirect = getContext().getTypeSize(EltTy) > FLen; + } else { + // This is a normal scalar > 2*XLen, such as fp128 on RV32. + IsRetIndirect = true; + } + } // We must track the number of GPRs used in order to conform to the RISC-V // ABI, as integer scalars passed in registers should have signext/zeroext diff --git a/clang/test/CodeGen/riscv32-ilp32d-abi.c b/clang/test/CodeGen/riscv32-ilp32d-abi.c index 078fcb6b5ab1..b5b451cee151 100644 --- a/clang/test/CodeGen/riscv32-ilp32d-abi.c +++ b/clang/test/CodeGen/riscv32-ilp32d-abi.c @@ -280,3 +280,27 @@ void f_double_u_arg(union double_u a) {} union double_u f_ret_double_u() { return (union double_u){1.0}; } + +// Test that we don't incorrectly think double+int/double+double structs will +// be returned indirectly and thus have an off-by-one error for the number of +// GPRs available (this is an edge case when structs > 2*XLEN are still +// returned in registers). This includes complex doubles, which are treated as +// double+double structs by the ABI. + +// CHECK: define { double, i32 } @f_ret_double_int32_s_double_int32_s_just_sufficient_gprs(i32 %a, i32 %b, i32 %c, i32 %d, i32 %e, i32 %f, i32 %g, double %0, i32 %1) +struct double_int32_s f_ret_double_int32_s_double_int32_s_just_sufficient_gprs( + int a, int b, int c, int d, int e, int f, int g, struct double_int32_s h) { + return (struct double_int32_s){1.0, 2}; +} + +// CHECK: define { double, double } @f_ret_double_double_s_double_int32_s_just_sufficient_gprs(i32 %a, i32 %b, i32 %c, i32 %d, i32 %e, i32 %f, i32 %g, double %0, i32 %1) +struct double_double_s f_ret_double_double_s_double_int32_s_just_sufficient_gprs( + int a, int b, int c, int d, int e, int f, int g, struct double_int32_s h) { + return (struct double_double_s){1.0, 2.0}; +} + +// CHECK: define { double, double } @f_ret_doublecomplex_double_int32_s_just_sufficient_gprs(i32 %a, i32 %b, i32 %c, i32 %d, i32 %e, i32 %f, i32 %g, double %0, i32 %1) +double __complex__ f_ret_doublecomplex_double_int32_s_just_sufficient_gprs( + int a, int b, int c, int d, int e, int f, int g, struct double_int32_s h) { + return 1.0; +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
