Checkpoint
This commit is contained in:
Scott Duensing
parent
91ac5476a5
commit
f80a49dc1e
5 changed files with 164 additions and 38 deletions
45
STATUS.md
45
STATUS.md
|
|
@ -65,30 +65,28 @@ which runs correctly under MAME (apple2gs).
|
|||
|
||||
## In flight (build-system level)
|
||||
|
||||
- **DWARF sidecar emission in link816** (#51): The link should produce
|
||||
a separate sidecar file with line-number / variable-location info
|
||||
that an IDE or post-mortem dumper can consume. Skeleton not yet
|
||||
written; deferred until other correctness work is done.
|
||||
- **DWARF sidecar — minimal version landed** (#51): `link816 --debug-out
|
||||
FILE` collects every `.debug_*` section from the input objects and
|
||||
writes them to a sidecar with section headers. Addresses are still
|
||||
object-file-local (no relocation processing). A consumer that wants
|
||||
source-mapped final-image addresses must re-run reloc against the
|
||||
text/rodata bases, or use offsets within their object scope. Future
|
||||
work: apply text/rodata relocations to `.debug_info` / `.debug_line`
|
||||
so addresses match the final image, and emit a TOC the consumer
|
||||
can index by source file or function.
|
||||
|
||||
## Known issues / workarounds
|
||||
|
||||
- **Greedy register allocator mis-orders spills** in two patterns
|
||||
(#69, #70):
|
||||
1. Functions where both `$a` and `$x` are live-in (i64-first-arg
|
||||
with a stack-output pointer, e.g. `udivmod(i64, i64, ptr)`).
|
||||
The TAX bridging `$x` to A clobbers `$a`'s value before the
|
||||
second STA can save it.
|
||||
2. Iterative quicksort with `if/else` recursion choice: complex
|
||||
live-ranges across two `swap()` calls produce wrong arg values.
|
||||
|
||||
Both reproduce only at `-O1`/`-O2` with greedy. Workaround:
|
||||
`-mllvm -regalloc=fast` for the affected translation unit.
|
||||
`softDouble.c` already requires this flag for `__muldf3` (build.sh
|
||||
applies it automatically).
|
||||
|
||||
Real fix is a pre-RA pass that pre-spills critical pointer
|
||||
arguments to memory, or a targeted fix in greedy's spill-ordering
|
||||
heuristic. Material work; deferred.
|
||||
- **Greedy register allocator mis-orders spills** in iterative
|
||||
quicksort with `if/else` recursion choice (#70). Complex live
|
||||
ranges across two `swap()` calls produce wrong pointer args.
|
||||
Reproduces only at `-O1`/`-O2` with greedy. Workaround:
|
||||
`-mllvm -regalloc=fast` for the affected translation unit, or
|
||||
rewrite the qsort with explicit recursion guards instead of the
|
||||
iterative tail-elim form. `softDouble.c` already uses this
|
||||
flag for `__muldf3` (build.sh applies it automatically). Real
|
||||
fix is either a pre-RA pass that explicitly spills loop-carried
|
||||
pointer args or a targeted greedy heuristic patch.
|
||||
|
||||
- **(d,s),y / (sr,s),y addressing wraps the bank** when Y is
|
||||
negative as 16-bit unsigned. Worked around by `W65816NegYIndY`
|
||||
|
|
@ -115,7 +113,10 @@ which runs correctly under MAME (apple2gs).
|
|||
several test cases. Acceptable today (Newton iterations still
|
||||
converge); revisit when an exact-match test suite lands.
|
||||
|
||||
- **DWARF sidecar** (#51) for source-level debugging.
|
||||
- **DWARF sidecar with relocations applied** — current (#51) version
|
||||
is raw section pass-through; addresses are object-file-local. A
|
||||
real source-level debugger needs the linker to apply text/rodata
|
||||
relocations to `.debug_info` / `.debug_line` first.
|
||||
|
||||
- **More of the C standard library**: `<math.h>` transcendental
|
||||
functions (sin, cos, exp, log, pow), `<string.h>` beyond what's
|
||||
|
|
|
|||
|
|
@ -2018,6 +2018,49 @@ EOF
|
|||
fi
|
||||
rm -f "$cAofFile" "$oAofFile" "$binAofFile"
|
||||
|
||||
log "check: MAME runs udivmod(0x123...DEF, 0x10000, &m) → q=0x12345_6789AB m=0xCDEF (#69)"
|
||||
cUdmFile="$(mktemp --suffix=.c)"
|
||||
oUdmFile="$(mktemp --suffix=.o)"
|
||||
binUdmFile="$(mktemp --suffix=.bin)"
|
||||
cat > "$cUdmFile" <<'EOF'
|
||||
__attribute__((noinline)) void switchToBank2(void) {
|
||||
__asm__ volatile ("sep #0x20\n.byte 0xa9,0x02\npha\nplb\nrep #0x20\n");
|
||||
}
|
||||
typedef unsigned long long u64;
|
||||
__attribute__((noinline)) u64 udivmod(u64 a, u64 b, u64 *out_mod) {
|
||||
*out_mod = a % b;
|
||||
return a / b;
|
||||
}
|
||||
int main(void) {
|
||||
u64 m;
|
||||
u64 q = udivmod(0x123456789ABCDEFULL, 0x10000ULL, &m);
|
||||
union { u64 u; unsigned short w[4]; } qu, mu;
|
||||
qu.u = q; mu.u = m;
|
||||
switchToBank2();
|
||||
*(volatile unsigned short *)0x5000 = qu.w[0];
|
||||
*(volatile unsigned short *)0x5002 = qu.w[1];
|
||||
*(volatile unsigned short *)0x5004 = qu.w[2];
|
||||
*(volatile unsigned short *)0x5006 = qu.w[3];
|
||||
*(volatile unsigned short *)0x5008 = mu.w[0];
|
||||
*(volatile unsigned short *)0x500a = mu.w[1];
|
||||
*(volatile unsigned short *)0x500c = mu.w[2];
|
||||
*(volatile unsigned short *)0x500e = mu.w[3];
|
||||
while (1) {}
|
||||
}
|
||||
EOF
|
||||
"$CLANG" --target=w65816 -O2 -ffunction-sections -c \
|
||||
"$cUdmFile" -o "$oUdmFile"
|
||||
"$PROJECT_ROOT/tools/link816" -o "$binUdmFile" --text-base 0x1000 \
|
||||
"$oCrt0F" "$oLibcF" "$oSfF" "$oSdF" "$oLibgccFile" "$oUdmFile" \
|
||||
>/dev/null 2>&1
|
||||
if ! bash "$PROJECT_ROOT/scripts/runInMame.sh" "$binUdmFile" --check \
|
||||
0x025000=89ab 0x025002=4567 0x025004=0123 0x025006=0000 \
|
||||
0x025008=cdef 0x02500a=0000 0x02500c=0000 0x02500e=0000 \
|
||||
>/dev/null 2>&1; then
|
||||
die "MAME: udivmod(...) wrong mod (i64-first-arg X-spill bug)"
|
||||
fi
|
||||
rm -f "$cUdmFile" "$oUdmFile" "$binUdmFile"
|
||||
|
||||
log "check: MAME runs sqr(10) → 100 (frame-less ADJCALLSTACKUP must emit PLY)"
|
||||
cSqrFile="$(mktemp --suffix=.c)"
|
||||
oSqrFile="$(mktemp --suffix=.o)"
|
||||
|
|
@ -2285,6 +2328,29 @@ EOF
|
|||
# Linker exports the synthetic __bss_start / __bss_end / etc.
|
||||
# symbols so crt0 can do BSS init and runtime malloc finds the
|
||||
# heap top.
|
||||
log "check: link816 --debug-out emits a DWARF sidecar (#51)"
|
||||
cDbgFile="$(mktemp --suffix=.c)"
|
||||
oDbgFile="$(mktemp --suffix=.o)"
|
||||
binDbgFile="$(mktemp --suffix=.bin)"
|
||||
dbgOutFile="$(mktemp --suffix=.dbg)"
|
||||
cat > "$cDbgFile" <<'EOF'
|
||||
int add(int a, int b) { return a + b; }
|
||||
int main(void) { return add(3, 4); }
|
||||
EOF
|
||||
"$CLANG" --target=w65816 -O2 -g -ffunction-sections -c "$cDbgFile" -o "$oDbgFile"
|
||||
"$PROJECT_ROOT/tools/link816" -o "$binDbgFile" --debug-out "$dbgOutFile" \
|
||||
--text-base 0x1000 "$oDbgFile" "$oLibgccFile" 2>/dev/null
|
||||
if ! head -1 "$dbgOutFile" | grep -q "DWARF sidecar"; then
|
||||
die "link816 --debug-out: sidecar missing header"
|
||||
fi
|
||||
if ! grep -q "SEC \.debug_info" "$dbgOutFile"; then
|
||||
die "link816 --debug-out: sidecar missing .debug_info section"
|
||||
fi
|
||||
if ! grep -q "SEC \.debug_line" "$dbgOutFile"; then
|
||||
die "link816 --debug-out: sidecar missing .debug_line section"
|
||||
fi
|
||||
rm -f "$cDbgFile" "$oDbgFile" "$binDbgFile" "$dbgOutFile"
|
||||
|
||||
log "check: link816 emits __bss_start, __bss_end, __heap_start"
|
||||
cBssFile="$(mktemp --suffix=.c)"
|
||||
oBssFile="$(mktemp --suffix=.o)"
|
||||
|
|
|
|||
|
|
@ -708,16 +708,61 @@ static uint32_t parseInt(const std::string &s) {
|
|||
static void usage(const char *argv0) {
|
||||
std::fprintf(stderr,
|
||||
"usage: %s -o <output> [--text-base ADDR] [--rodata-base ADDR]\n"
|
||||
" [--bss-base ADDR] [--map FILE] <input.o> ...\n",
|
||||
" [--bss-base ADDR] [--map FILE] [--debug-out FILE]\n"
|
||||
" <input.o> ...\n",
|
||||
argv0);
|
||||
std::exit(2);
|
||||
}
|
||||
|
||||
// ---------------------------------------------------------------- DWARF
|
||||
// Sidecar emission. Walks each input object and concatenates every
|
||||
// section whose name starts with `.debug_`. Each section is prefixed
|
||||
// by a small ASCII-readable header line:
|
||||
//
|
||||
// ; OBJ <objname> SEC <sectionname> SIZE <bytes>
|
||||
//
|
||||
// followed by the raw section bytes. Address-bearing sections
|
||||
// (.debug_info, .debug_line, .debug_aranges, .debug_loc, etc.) are
|
||||
// written WITHOUT relocation processing — addresses are object-file-
|
||||
// local, not final-image-local. A consumer that wants source-mapped
|
||||
// addresses needs to either (a) re-run reloc against the linked
|
||||
// section bases, or (b) use the relative offsets within their object
|
||||
// scope. Better than nothing for a single-TU debug session.
|
||||
static void writeDebugSidecar(
|
||||
const std::string &path,
|
||||
const std::vector<std::unique_ptr<InputObject>> &objs) {
|
||||
std::ofstream f(path, std::ios::binary);
|
||||
if (!f) die("cannot open '" + path + "' for writing");
|
||||
f << "; llvm816 link816 DWARF sidecar v0\n";
|
||||
f << "; Object-file-local addresses; not relocated to final image.\n";
|
||||
size_t total = 0;
|
||||
size_t kept = 0;
|
||||
for (const auto &objPtr : objs) {
|
||||
const InputObject &obj = *objPtr;
|
||||
for (const Section &sec : obj.sections) {
|
||||
if (sec.name.rfind(".debug_", 0) != 0) continue;
|
||||
if (sec.size == 0) continue;
|
||||
f << "; OBJ " << obj.path << " SEC " << sec.name
|
||||
<< " SIZE " << sec.size << "\n";
|
||||
f.write(reinterpret_cast<const char *>(obj.raw.data()
|
||||
+ sec.fileOffset),
|
||||
sec.size);
|
||||
f << "\n";
|
||||
total += sec.size;
|
||||
kept++;
|
||||
}
|
||||
}
|
||||
std::fprintf(stderr,
|
||||
"debug sidecar: %zu sections, %zu bytes -> %s\n",
|
||||
kept, total, path.c_str());
|
||||
}
|
||||
|
||||
} // anonymous namespace
|
||||
|
||||
int main(int argc, char **argv) {
|
||||
std::string outPath;
|
||||
std::string mapPath;
|
||||
std::string debugOutPath;
|
||||
Linker linker;
|
||||
|
||||
int i = 1;
|
||||
|
|
@ -738,6 +783,9 @@ int main(int argc, char **argv) {
|
|||
} else if (a == "--map") {
|
||||
if (++i >= argc) usage(argv[0]);
|
||||
mapPath = argv[i++];
|
||||
} else if (a == "--debug-out") {
|
||||
if (++i >= argc) usage(argv[0]);
|
||||
debugOutPath = argv[i++];
|
||||
} else if (a == "-h" || a == "--help") {
|
||||
usage(argv[0]);
|
||||
} else if (!a.empty() && a[0] == '-') {
|
||||
|
|
@ -757,6 +805,7 @@ int main(int argc, char **argv) {
|
|||
f.write(reinterpret_cast<const char *>(image.data()), image.size());
|
||||
|
||||
if (!mapPath.empty()) linker.writeMap(mapPath);
|
||||
if (!debugOutPath.empty()) writeDebugSidecar(debugOutPath, linker.objs);
|
||||
|
||||
std::fprintf(stderr,
|
||||
"linked: text=[0x%04x+%u] rodata=[0x%04x+%u] bss=[0x%04x+%u] "
|
||||
|
|
|
|||
|
|
@ -638,6 +638,17 @@ SDValue W65816TargetLowering::LowerFormalArguments(
|
|||
bool I32FirstArg =
|
||||
Ins.size() >= 2 && Ins[0].VT == MVT::i16 && Ins[1].VT == MVT::i16 &&
|
||||
Ins[0].OrigArgIndex == 0 && Ins[1].OrigArgIndex == 0;
|
||||
// True iff the FIRST original arg spans 4 i16s (i.e., is i64). Used
|
||||
// below to choose the Img16-via-STX_DP X-arg path for i64 callees,
|
||||
// which dodges greedy's TXA-bridge-clobbers-A spill bug. i32-first
|
||||
// doesn't get the same treatment because the change pessimizes
|
||||
// simple functions like `int add32(int a, int b) { return a+b; }`
|
||||
// where greedy's regular A:X handling is fine.
|
||||
bool I64FirstArg =
|
||||
Ins.size() >= 4 && Ins[0].VT == MVT::i16 && Ins[1].VT == MVT::i16 &&
|
||||
Ins[2].VT == MVT::i16 && Ins[3].VT == MVT::i16 &&
|
||||
Ins[0].OrigArgIndex == 0 && Ins[1].OrigArgIndex == 0 &&
|
||||
Ins[2].OrigArgIndex == 0 && Ins[3].OrigArgIndex == 0;
|
||||
|
||||
unsigned ArgIdx = 0;
|
||||
// Stack offset is measured from S+1 (the WDC convention) and grows
|
||||
|
|
@ -655,8 +666,16 @@ SDValue W65816TargetLowering::LowerFormalArguments(
|
|||
MRI.addLiveIn(W65816::A, VReg);
|
||||
InVals.push_back(DAG.getCopyFromReg(Chain, DL, VReg, VT));
|
||||
} else if (ArgIdx == 1 && I32FirstArg) {
|
||||
// i32 first-arg hi half: in X.
|
||||
Register VReg = MRI.createVirtualRegister(&W65816::Idx16RegClass);
|
||||
// First-arg hi half (or arg0_ml for i64-first-arg): in X.
|
||||
// For i64-first-arg signatures (4 i16s with OrigArgIndex 0), use
|
||||
// Img16 so greedy parks the value in an IMG slot via STX_DP,
|
||||
// dodging the TXA-bridge-clobbers-A spill bug. i32-first stays
|
||||
// on the original Idx16 path because the change pessimizes
|
||||
// simple cases (verified: vprintf's writeULong/__udivsi3 chain
|
||||
// crashes if i32-first is also rerouted). Caught by udivmod.
|
||||
const TargetRegisterClass *RC = I64FirstArg ? &W65816::Img16RegClass
|
||||
: &W65816::Idx16RegClass;
|
||||
Register VReg = MRI.createVirtualRegister(RC);
|
||||
MRI.addLiveIn(W65816::X, VReg);
|
||||
InVals.push_back(DAG.getCopyFromReg(Chain, DL, VReg, MVT::i16));
|
||||
} else {
|
||||
|
|
|
|||
|
|
@ -92,10 +92,10 @@ void W65816InstrInfo::copyPhysReg(MachineBasicBlock &MBB,
|
|||
BuildMI(MBB, I, DL, get(W65816::STA_DP)).addImm(dstImg);
|
||||
return;
|
||||
}
|
||||
// X → IMGn / IMGn → X: STX dp / LDX dp. Avoids the A-bridge that
|
||||
// TAX/TXA would impose; critical for i32-first-arg signatures
|
||||
// (live-in $a + $x) where bridging X via A clobbers $a's value
|
||||
// before it can be saved. Caught by udivmod and iterative qsort.
|
||||
// X → IMGn / IMGn → X: STX dp / LDX dp. Used by the i64-first-arg
|
||||
// entry COPY (LowerFormalArguments routes arg0_ml through Img16 to
|
||||
// dodge the TXA-bridge-clobbers-A spill bug for udivmod-shaped
|
||||
// signatures).
|
||||
if (dstImg >= 0 && SrcReg == W65816::X) {
|
||||
BuildMI(MBB, I, DL, get(W65816::STX_DP)).addImm(dstImg);
|
||||
return;
|
||||
|
|
@ -104,15 +104,6 @@ void W65816InstrInfo::copyPhysReg(MachineBasicBlock &MBB,
|
|||
BuildMI(MBB, I, DL, get(W65816::LDX_DP)).addImm(srcImg);
|
||||
return;
|
||||
}
|
||||
// Y → IMGn / IMGn → Y: STY dp / LDY dp — symmetric.
|
||||
if (dstImg >= 0 && SrcReg == W65816::Y) {
|
||||
BuildMI(MBB, I, DL, get(W65816::STY_DP)).addImm(dstImg);
|
||||
return;
|
||||
}
|
||||
if (DestReg == W65816::Y && srcImg >= 0) {
|
||||
BuildMI(MBB, I, DL, get(W65816::LDY_DP)).addImm(srcImg);
|
||||
return;
|
||||
}
|
||||
// DPF0 → A: emit `LDA $F0`. DPF0 is the pseudo-physreg carrier
|
||||
// for an i64-returning call's high 16 bits; LowerCall builds a
|
||||
// CopyFromReg(DPF0) glued to the call so the SDAG combiner /
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue