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/* -*- 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"
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