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Allow the bit/res/set bit index to be determined at link time (#1654)

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This increments the object file revision number from 11 to 12
since it adds a new `RPN_BIT_INDEX` command.
This commit is contained in:
Rangi
2025-02-12 17:14:10 +01:00
committed by GitHub
parent 48412e9c56
commit 2aef09c8d9
12 changed files with 97 additions and 19 deletions
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43
src/asm/parser.y
View File

@@ -325,6 +325,7 @@
// `relocexpr_no_str` exists because strings usually count as numeric expressions, but some
// contexts treat numbers and strings differently, e.g. `db "string"` or `print "string"`.
%type <Expression> relocexpr_no_str
%type <Expression> reloc_3bit
%type <Expression> reloc_8bit
%type <Expression> reloc_8bit_offset
%type <Expression> reloc_16bit
@@ -333,7 +334,6 @@
%type <int32_t> iconst
%type <int32_t> uconst
// Constant numbers used only in specific contexts
%type <int32_t> bit_const
%type <int32_t> precision_arg
%type <int32_t> rs_uconst
%type <int32_t> sect_org
@@ -1214,13 +1214,10 @@ print_expr:
}
;
bit_const:
iconst {
$$ = $1;
if ($$ < 0 || $$ > 7) {
::error("Bit number must be between 0 and 7, not %" PRId32 "\n", $$);
$$ = 0;
}
reloc_3bit:
relocexpr {
$$ = std::move($1);
$$.checkNBit(3);
}
;
@@ -1789,9 +1786,15 @@ sm83_and:
;
sm83_bit:
SM83_BIT bit_const COMMA reg_r {
SM83_BIT reloc_3bit COMMA reg_r {
uint8_t mask = static_cast<uint8_t>(0x40 | $4);
$2.makeCheckBitIndex(mask);
sect_ConstByte(0xCB);
sect_ConstByte(0x40 | ($2 << 3) | $4);
if (!$2.isKnown()) {
sect_RelByte($2, 0);
} else {
sect_ConstByte(mask | ($2.value() << 3));
}
}
;
@@ -2103,9 +2106,15 @@ sm83_push:
;
sm83_res:
SM83_RES bit_const COMMA reg_r {
SM83_RES reloc_3bit COMMA reg_r {
uint8_t mask = static_cast<uint8_t>(0x80 | $4);
$2.makeCheckBitIndex(mask);
sect_ConstByte(0xCB);
sect_ConstByte(0x80 | ($2 << 3) | $4);
if (!$2.isKnown()) {
sect_RelByte($2, 0);
} else {
sect_ConstByte(mask | ($2.value() << 3));
}
}
;
@@ -2204,9 +2213,15 @@ sm83_scf:
;
sm83_set:
SM83_SET bit_const COMMA reg_r {
SM83_SET reloc_3bit COMMA reg_r {
uint8_t mask = static_cast<uint8_t>(0xC0 | $4);
$2.makeCheckBitIndex(mask);
sect_ConstByte(0xCB);
sect_ConstByte(0xC0 | ($2 << 3) | $4);
if (!$2.isKnown()) {
sect_RelByte($2, 0);
} else {
sect_ConstByte(mask | ($2.value() << 3));
}
}
;

16
src/asm/rpn.cpp
View File

@@ -355,6 +355,7 @@ void Expression::makeUnaryOp(RPNCommand op, Expression &&src) {
case RPN_STARTOF_SECTTYPE:
case RPN_HRAM:
case RPN_RST:
case RPN_BIT_INDEX:
case RPN_CONST:
case RPN_SYM:
fatalerror("%d is not an unary operator\n", op);
@@ -514,6 +515,7 @@ void Expression::makeBinaryOp(RPNCommand op, Expression &&src1, Expression const
case RPN_STARTOF_SECTTYPE:
case RPN_HRAM:
case RPN_RST:
case RPN_BIT_INDEX:
case RPN_HIGH:
case RPN_LOW:
case RPN_BITWIDTH:
@@ -608,6 +610,20 @@ void Expression::makeCheckRST() {
}
}
void Expression::makeCheckBitIndex(uint8_t mask) {
assume((mask & 0xC0) != 0x00); // The high two bits must correspond to BIT, RES, or SET
if (!isKnown()) {
uint8_t *ptr = reserveSpace(2);
*ptr++ = RPN_BIT_INDEX;
*ptr = mask;
} else if (int32_t val = value(); val & ~0x07) {
// A valid bit index must be masked with 0x07
static char const *instructions[4] = {"instruction", "BIT", "RES", "SET"};
error("Invalid bit index %" PRId32 " for %s\n", val, instructions[mask >> 6]);
}
}
// Checks that an RPN expression's value fits within N bits (signed or unsigned)
void Expression::checkNBit(uint8_t n) const {
if (isKnown()) {