/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ /* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ // Implement shared vtbl methods. #include "xptcprivate.h" // Prior to POWER8, all 64-bit Power ISA systems used ELF v1 ABI, found // here: // https://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.html // and in particular: // https://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.html#FUNC-CALL // Little-endian ppc64le, however, uses ELF v2 ABI, which is here: // http://openpowerfoundation.org/wp-content/uploads/resources/leabi/leabi-20170510.pdf // and in particular section 2.2, page 22. However, most big-endian ppc64 // systems still use ELF v1, so this file should support both. // // Both ABIs pass the first 8 integral parameters and the first 13 floating // point parameters in registers r3-r10 and f1-f13. No stack space is // allocated for these by the caller. The rest of the parameters are passed // in the caller's stack area. The stack pointer must stay 16-byte aligned. const uint32_t GPR_COUNT = 7; const uint32_t FPR_COUNT = 13; // PrepareAndDispatch() is called by SharedStub() and calls the actual method. // // - 'args[]' contains the arguments passed on stack // - 'gpregs[]' contains the arguments passed in integer registers // - 'fpregs[]' contains the arguments passed in floating point registers // // The parameters are mapped into an array of type 'nsXPTCMiniVariant' // and then the method gets called. // // Both ABIs use the same register assignment strategy, as per this // example from V1 ABI section 3.2.3 and V2 ABI section 2.2.3.2 [page 43]: // // typedef struct { // int a; // double dd; // } sparm; // sparm s, t; // int c, d, e; // long double ld; // double ff, gg, hh; // // x = func(c, ff, d, ld, s, gg, t, e, hh); // // Parameter Register Offset in parameter save area // c r3 0-7 (not stored in parameter save area) // ff f1 8-15 (not stored) // d r5 16-23 (not stored) // ld f2,f3 24-39 (not stored) // s r8,r9 40-55 (not stored) // gg f4 56-63 (not stored) // t (none) 64-79 (stored in parameter save area) // e (none) 80-87 (stored) // hh f5 88-95 (not stored) // // i.e., each successive FPR usage skips a GPR, but not the other way around. extern "C" nsresult ATTRIBUTE_USED PrepareAndDispatch(nsXPTCStubBase * self, uint32_t methodIndex, uint64_t * args, uint64_t * gpregs, double *fpregs) { nsXPTCMiniVariant paramBuffer[PARAM_BUFFER_COUNT]; const nsXPTMethodInfo* info; uint32_t paramCount; uint32_t i; NS_ASSERTION(self,"no self"); self->mEntry->GetMethodInfo(uint16_t(methodIndex), &info); NS_ASSERTION(info,"no method info"); if (!info) return NS_ERROR_UNEXPECTED; paramCount = info->GetParamCount(); const uint8_t indexOfJSContext = info->IndexOfJSContext(); uint64_t* ap = args; // |that| is implicit in the calling convention; we really do start at the // first GPR (as opposed to x86_64). uint32_t nr_gpr = 0; uint32_t nr_fpr = 0; uint64_t value; for(i = 0; i < paramCount; i++) { const nsXPTParamInfo& param = info->GetParam(i); const nsXPTType& type = param.GetType(); nsXPTCMiniVariant* dp = ¶mBuffer[i]; if (i == indexOfJSContext) { if (nr_gpr < GPR_COUNT) nr_gpr++; else ap++; } if (!param.IsOut() && type == nsXPTType::T_DOUBLE) { if (nr_fpr < FPR_COUNT) { dp->val.d = fpregs[nr_fpr++]; // Even if we have enough FPRs, still skip space in // the parameter area if we ran out of placeholder GPRs. if (nr_gpr < GPR_COUNT) { nr_gpr++; } else { ap++; } } else { dp->val.d = *(double*)ap++; } continue; } if (!param.IsOut() && type == nsXPTType::T_FLOAT) { if (nr_fpr < FPR_COUNT) { // Single-precision floats are passed in FPRs too. dp->val.f = (float)fpregs[nr_fpr++]; if (nr_gpr < GPR_COUNT) { nr_gpr++; } else { ap++; } } else { #ifdef __LITTLE_ENDIAN__ dp->val.f = *(float*)ap++; #else // Big endian needs adjustment to point to the least // significant word. float* p = (float*)ap; p++; dp->val.f = *p; ap++; #endif } continue; } if (nr_gpr < GPR_COUNT) value = gpregs[nr_gpr++]; else value = *ap++; if (param.IsOut() || !type.IsArithmetic()) { dp->val.p = (void*) value; continue; } switch (type) { case nsXPTType::T_I8: dp->val.i8 = (int8_t) value; break; case nsXPTType::T_I16: dp->val.i16 = (int16_t) value; break; case nsXPTType::T_I32: dp->val.i32 = (int32_t) value; break; case nsXPTType::T_I64: dp->val.i64 = (int64_t) value; break; case nsXPTType::T_U8: dp->val.u8 = (uint8_t) value; break; case nsXPTType::T_U16: dp->val.u16 = (uint16_t) value; break; case nsXPTType::T_U32: dp->val.u32 = (uint32_t) value; break; case nsXPTType::T_U64: dp->val.u64 = (uint64_t) value; break; case nsXPTType::T_BOOL: dp->val.b = (bool) value; break; case nsXPTType::T_CHAR: dp->val.c = (char) value; break; case nsXPTType::T_WCHAR: dp->val.wc = (wchar_t) value; break; default: NS_ERROR("bad type"); break; } } nsresult result = self->mOuter->CallMethod((uint16_t) methodIndex, info, paramBuffer); return result; } // Load r11 with the constant 'n' and branch to SharedStub(). // // As G++3 ABI contains the length of the functionname in the mangled // name, it is difficult to get a generic assembler mechanism like // in the G++ 2.95 case. // XXX Yes, it's ugly that we're relying on gcc's name-mangling here; // however, it's quick, dirty, and'll break when the ABI changes on // us, which is what we want ;-). // Create names would be like: // _ZN14nsXPTCStubBase5Stub1Ev // _ZN14nsXPTCStubBase6Stub12Ev // _ZN14nsXPTCStubBase7Stub123Ev // _ZN14nsXPTCStubBase8Stub1234Ev // etc. // Use assembler directives to get the names right. #if _CALL_ELF == 2 # define STUB_ENTRY(n) \ __asm__ ( \ ".section \".text\" \n\t" \ ".align 2 \n\t" \ ".if "#n" < 10 \n\t" \ ".globl _ZN14nsXPTCStubBase5Stub"#n"Ev \n\t" \ ".type _ZN14nsXPTCStubBase5Stub"#n"Ev,@function \n\n" \ "_ZN14nsXPTCStubBase5Stub"#n"Ev: \n\t" \ "0: addis 2,12,.TOC.-0b@ha \n\t" \ "addi 2,2,.TOC.-0b@l \n\t" \ ".localentry _ZN14nsXPTCStubBase5Stub"#n"Ev,.-_ZN14nsXPTCStubBase5Stub"#n"Ev \n\t" \ \ ".elseif "#n" < 100 \n\t" \ ".globl _ZN14nsXPTCStubBase6Stub"#n"Ev \n\t" \ ".type _ZN14nsXPTCStubBase6Stub"#n"Ev,@function \n\n" \ "_ZN14nsXPTCStubBase6Stub"#n"Ev: \n\t" \ "0: addis 2,12,.TOC.-0b@ha \n\t" \ "addi 2,2,.TOC.-0b@l \n\t" \ ".localentry _ZN14nsXPTCStubBase6Stub"#n"Ev,.-_ZN14nsXPTCStubBase6Stub"#n"Ev \n\t" \ \ ".elseif "#n" < 1000 \n\t" \ ".globl _ZN14nsXPTCStubBase7Stub"#n"Ev \n\t" \ ".type _ZN14nsXPTCStubBase7Stub"#n"Ev,@function \n\n" \ "_ZN14nsXPTCStubBase7Stub"#n"Ev: \n\t" \ "0: addis 2,12,.TOC.-0b@ha \n\t" \ "addi 2,2,.TOC.-0b@l \n\t" \ ".localentry _ZN14nsXPTCStubBase7Stub"#n"Ev,.-_ZN14nsXPTCStubBase7Stub"#n"Ev \n\t" \ \ ".else \n\t" \ ".err \"stub number "#n" >= 1000 not yet supported\"\n" \ ".endif \n\t" \ \ "li 11,"#n" \n\t" \ "b SharedStub \n" \ ); #else # define STUB_ENTRY(n) \ __asm__ ( \ ".section \".toc\",\"aw\" \n\t" \ ".section \".text\" \n\t" \ ".align 2 \n\t" \ ".if "#n" < 10 \n\t" \ ".globl _ZN14nsXPTCStubBase5Stub"#n"Ev \n\t" \ ".section \".opd\",\"aw\" \n\t" \ ".align 3 \n\t" \ "_ZN14nsXPTCStubBase5Stub"#n"Ev: \n\t" \ ".quad ._ZN14nsXPTCStubBase5Stub"#n"Ev,.TOC.@tocbase \n\t" \ ".previous \n\t" \ ".type _ZN14nsXPTCStubBase5Stub"#n"Ev,@function \n\n" \ "._ZN14nsXPTCStubBase5Stub"#n"Ev: \n\t" \ \ ".elseif "#n" < 100 \n\t" \ ".globl _ZN14nsXPTCStubBase6Stub"#n"Ev \n\t" \ ".section \".opd\",\"aw\" \n\t" \ ".align 3 \n\t" \ "_ZN14nsXPTCStubBase6Stub"#n"Ev: \n\t" \ ".quad ._ZN14nsXPTCStubBase6Stub"#n"Ev,.TOC.@tocbase \n\t" \ ".previous \n\t" \ ".type _ZN14nsXPTCStubBase6Stub"#n"Ev,@function \n\n" \ "._ZN14nsXPTCStubBase6Stub"#n"Ev: \n\t" \ \ ".elseif "#n" < 1000 \n\t" \ ".globl _ZN14nsXPTCStubBase7Stub"#n"Ev \n\t" \ ".section \".opd\",\"aw\" \n\t" \ ".align 3 \n\t" \ "_ZN14nsXPTCStubBase7Stub"#n"Ev: \n\t" \ ".quad ._ZN14nsXPTCStubBase7Stub"#n"Ev,.TOC.@tocbase \n\t" \ ".previous \n\t" \ ".type _ZN14nsXPTCStubBase7Stub"#n"Ev,@function \n\n" \ "._ZN14nsXPTCStubBase7Stub"#n"Ev: \n\t" \ \ ".else \n\t" \ ".err \"stub number "#n" >= 1000 not yet supported\"\n" \ ".endif \n\t" \ \ "li 11,"#n" \n\t" \ "b SharedStub \n" \ ); #endif #define SENTINEL_ENTRY(n) \ nsresult nsXPTCStubBase::Sentinel##n() \ { \ NS_ERROR("nsXPTCStubBase::Sentinel called"); \ return NS_ERROR_NOT_IMPLEMENTED; \ } #include "xptcstubsdef.inc"