factor/vm/instruction_operands.cpp

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#include "master.hpp"
namespace factor
{
/* Load a 32-bit value from a PowerPC LIS/ORI sequence */
fixnum instruction_operand::load_value_2_2()
{
cell *ptr = (cell *)pointer;
cell hi = (ptr[-1] & 0xffff);
cell lo = (ptr[ 0] & 0xffff);
return hi << 16 | lo;
}
/* Load a value from a bitfield of a PowerPC instruction */
fixnum instruction_operand::load_value_masked(cell mask, fixnum shift)
{
cell *ptr = (cell *)pointer;
return (*ptr & mask) << shift;
}
fixnum instruction_operand::load_value(cell relative_to)
{
switch(rel_class)
{
case RC_ABSOLUTE_CELL:
return *(cell *)pointer;
case RC_ABSOLUTE:
return *(u32*)pointer;
case RC_RELATIVE:
return *(s32*)pointer + relative_to + sizeof(u32);
case RC_ABSOLUTE_PPC_2_2:
return load_value_2_2();
case RC_ABSOLUTE_PPC_2:
return load_value_masked(rel_absolute_ppc_2_mask,0);
case RC_RELATIVE_PPC_2:
return load_value_masked(rel_relative_ppc_2_mask,0) + relative_to;
case RC_RELATIVE_PPC_3:
return load_value_masked(rel_relative_ppc_3_mask,0) + relative_to;
case RC_RELATIVE_ARM_3:
return load_value_masked(rel_relative_arm_3_mask,2) + relative_to + sizeof(cell) * 2;
case RC_INDIRECT_ARM:
return load_value_masked(rel_indirect_arm_mask,0) + relative_to + sizeof(cell);
case RC_INDIRECT_ARM_PC:
return load_value_masked(rel_indirect_arm_mask,0) + relative_to + sizeof(cell) * 2;
default:
critical_error("Bad rel class",rel_class);
return 0;
}
}
fixnum instruction_operand::load_value()
{
return load_value(pointer);
}
code_block *instruction_operand::load_code_block()
{
return ((code_block *)load_value() - 1);
}
/* Store a 32-bit value into a PowerPC LIS/ORI sequence */
void instruction_operand::store_value_2_2(fixnum value)
{
cell *ptr = (cell *)pointer;
ptr[-1] = ((ptr[-1] & ~0xffff) | ((value >> 16) & 0xffff));
ptr[ 0] = ((ptr[ 0] & ~0xffff) | (value & 0xffff));
}
/* Store a value into a bitfield of a PowerPC instruction */
void instruction_operand::store_value_masked(fixnum value, cell mask, fixnum shift)
{
cell *ptr = (cell *)pointer;
/* This is unaccurate but good enough */
fixnum test = (fixnum)mask >> 1;
if(value <= -test || value >= test)
critical_error("Value does not fit inside relocation",0);
*ptr = ((*ptr & ~mask) | ((value >> shift) & mask));
}
void instruction_operand::store_value(fixnum absolute_value)
{
fixnum relative_value = absolute_value - pointer;
switch(rel_class)
{
case RC_ABSOLUTE_CELL:
*(cell *)pointer = absolute_value;
break;
case RC_ABSOLUTE:
*(u32*)pointer = absolute_value;
break;
case RC_RELATIVE:
*(s32*)pointer = relative_value - sizeof(u32);
break;
case RC_ABSOLUTE_PPC_2_2:
store_value_2_2(absolute_value);
break;
case RC_ABSOLUTE_PPC_2:
store_value_masked(absolute_value,rel_absolute_ppc_2_mask,0);
break;
case RC_RELATIVE_PPC_2:
store_value_masked(relative_value,rel_relative_ppc_2_mask,0);
break;
case RC_RELATIVE_PPC_3:
store_value_masked(relative_value,rel_relative_ppc_3_mask,0);
break;
case RC_RELATIVE_ARM_3:
store_value_masked(relative_value - sizeof(cell) * 2,rel_relative_arm_3_mask,2);
break;
case RC_INDIRECT_ARM:
store_value_masked(relative_value - sizeof(cell),rel_indirect_arm_mask,0);
break;
case RC_INDIRECT_ARM_PC:
store_value_masked(relative_value - sizeof(cell) * 2,rel_indirect_arm_mask,0);
break;
default:
critical_error("Bad rel class",rel_class);
break;
}
}
void instruction_operand::store_code_block(code_block *compiled)
{
store_value((cell)compiled->xt());
}
}