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@justinfargnoli justinfargnoli self-assigned this Feb 1, 2025
justinfargnoli pushed a commit that referenced this pull request Feb 5, 2025
…ible (llvm#123752)

This patch adds a new option `-aarch64-enable-zpr-predicate-spills`
(which is disabled by default), this option replaces predicate spills
with vector spills in streaming[-compatible] functions.

For example:

```
str	p8, [sp, llvm#7, mul vl]            // 2-byte Folded Spill
// ...
ldr	p8, [sp, llvm#7, mul vl]            // 2-byte Folded Reload
```

Becomes:

```
mov	z0.b, p8/z, #1
str	z0, [sp]                        // 16-byte Folded Spill
// ...
ldr	z0, [sp]                        // 16-byte Folded Reload
ptrue	p4.b
cmpne	p8.b, p4/z, z0.b, #0
```

This is done to avoid streaming memory hazards between FPR/vector and
predicate spills, which currently occupy the same stack area even when
the `-aarch64-stack-hazard-size` flag is set.

This is implemented with two new pseudos SPILL_PPR_TO_ZPR_SLOT_PSEUDO
and FILL_PPR_FROM_ZPR_SLOT_PSEUDO. The expansion of these pseudos
handles scavenging the required registers (z0 in the above example) and,
in the worst case spilling a register to an emergency stack slot in the
expansion. The condition flags are also preserved around the `cmpne` in
case they are live at the expansion point.
justinfargnoli pushed a commit that referenced this pull request Feb 11, 2025
…StrictPackMatch field (llvm#126215)

This addresses the MSAN failure reported
in
llvm#125791 (comment):
```
==5633==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 in clang::ASTNodeImporter::CallOverloadedCreateFun<clang::ClassTemplateSpecializationDecl>::operator()
    #1 in bool clang::ASTNodeImporter::GetImportedOrCreateSpecialDecl<...>
...
```

The ASTImporter reads `D->hasStrictPackMatch()` and forwards it to the
constructor of the destination `ClassTemplateSpecializationDecl`. But if
`D` is a decl that LLDB created from debug-info, it would've been
created using `ClassTemplateSpecializationDecl::CreateDeserialized`,
which doesn't initialize the `StrictPackMatch` field.

This patch just initializes the field to a fixed value of `false`, to
preserve previous behaviour and avoid the use-of-uninitialized-value.

An alternative would be to always initialize it in the
`ClassTemplateSpecializationDecl` constructor, but there were
reservations about providing a default value for it because it might
lead to hard-to-diagnose problems down the line.
justinfargnoli pushed a commit that referenced this pull request Aug 1, 2025
Extend support in LLDB for WebAssembly. This PR adds a new Process
plugin (ProcessWasm) that extends ProcessGDBRemote for WebAssembly
targets. It adds support for WebAssembly's memory model with separate
address spaces, and the ability to fetch the call stack from the
WebAssembly runtime.

I have tested this change with the WebAssembly Micro Runtime (WAMR,
https://github.com/bytecodealliance/wasm-micro-runtime) which implements
a GDB debug stub and supports the qWasmCallStack packet.

```
(lldb) process connect --plugin wasm connect://localhost:4567
Process 1 stopped
* thread #1, name = 'nobody', stop reason = trace
    frame #0: 0x40000000000001ad
wasm32_args.wasm`main:
->  0x40000000000001ad <+3>:  global.get 0
    0x40000000000001b3 <+9>:  i32.const 16
    0x40000000000001b5 <+11>: i32.sub
    0x40000000000001b6 <+12>: local.set 0
(lldb) b add
Breakpoint 1: where = wasm32_args.wasm`add + 28 at test.c:4:12, address = 0x400000000000019c
(lldb) c
Process 1 resuming
Process 1 stopped
* thread #1, name = 'nobody', stop reason = breakpoint 1.1
    frame #0: 0x400000000000019c wasm32_args.wasm`add(a=<unavailable>, b=<unavailable>) at test.c:4:12
   1    int
   2    add(int a, int b)
   3    {
-> 4        return a + b;
   5    }
   6
   7    int
(lldb) bt
* thread #1, name = 'nobody', stop reason = breakpoint 1.1
  * frame #0: 0x400000000000019c wasm32_args.wasm`add(a=<unavailable>, b=<unavailable>) at test.c:4:12
    frame #1: 0x40000000000001e5 wasm32_args.wasm`main at test.c:12:12
    frame llvm#2: 0x40000000000001fe wasm32_args.wasm
```

This PR is based on an unmerged patch from Paolo Severini:
https://reviews.llvm.org/D78801. I intentionally stuck to the
foundations to keep this PR small. I have more PRs in the pipeline to
support the other features/packets.

My motivation for supporting Wasm is to support debugging Swift compiled
to WebAssembly:
https://www.swift.org/documentation/articles/wasm-getting-started.html
justinfargnoli pushed a commit that referenced this pull request Aug 5, 2025
…erver (llvm#148774)

Summary:
There was a deadlock was introduced by [PR
llvm#146441](llvm#146441) which changed
`CurrentThreadIsPrivateStateThread()` to
`CurrentThreadPosesAsPrivateStateThread()`. This change caused the
execution path in
[`ExecutionContextRef::SetTargetPtr()`](https://github.com/llvm/llvm-project/blob/10b5558b61baab59c7d3dff37ffdf0861c0cc67a/lldb/source/Target/ExecutionContext.cpp#L513)
to now enter a code block that was previously skipped, triggering
[`GetSelectedFrame()`](https://github.com/llvm/llvm-project/blob/10b5558b61baab59c7d3dff37ffdf0861c0cc67a/lldb/source/Target/ExecutionContext.cpp#L522)
which leads to a deadlock.

Thread 1 gets m_modules_mutex in
[`ModuleList::AppendImpl`](https://github.com/llvm/llvm-project/blob/96148f92146e5211685246722664e51ec730e7ba/lldb/source/Core/ModuleList.cpp#L218),
Thread 3 gets m_language_runtimes_mutex in
[`GetLanguageRuntime`](https://github.com/llvm/llvm-project/blob/96148f92146e5211685246722664e51ec730e7ba/lldb/source/Target/Process.cpp#L1501),
but then Thread 1 waits for m_language_runtimes_mutex in
[`GetLanguageRuntime`](https://github.com/llvm/llvm-project/blob/96148f92146e5211685246722664e51ec730e7ba/lldb/source/Target/Process.cpp#L1501)
while Thread 3 waits for m_modules_mutex in
[`ScanForGNUstepObjCLibraryCandidate`](https://github.com/llvm/llvm-project/blob/96148f92146e5211685246722664e51ec730e7ba/lldb/source/Plugins/LanguageRuntime/ObjC/GNUstepObjCRuntime/GNUstepObjCRuntime.cpp#L57).

This fixes the deadlock by adding a scoped block around the mutex lock
before the call to the notifier, and moved the notifier call outside of
the mutex-guarded section. The notifier call
[`NotifyModuleAdded`](https://github.com/llvm/llvm-project/blob/96148f92146e5211685246722664e51ec730e7ba/lldb/source/Target/Target.cpp#L1810)
should be thread-safe, since the module should be added to the
`ModuleList` before the mutex is released, and the notifier doesn't
modify the module list further, and the call is operates on local state
and the `Target` instance.

### Deadlocked Thread backtraces:
```
* thread llvm#3, name = 'dbg.evt-handler', stop reason = signal SIGSTOP
  * frame #0: 0x00007f2f1e2973dc libc.so.6`futex_wait(private=0, expected=2, futex_word=0x0000563786bd5f40) at    futex-internal.h:146:13
   /*... a bunch of mutex related bt ... */    
   liblldb.so.21.0git`std::lock_guard<std::recursive_mutex>::lock_guard(this=0x00007f2f0f1927b0, __m=0x0000563786bd5f40) at std_mutex.h:229:19
    frame llvm#8: 0x00007f2f27946eb7 liblldb.so.21.0git`ScanForGNUstepObjCLibraryCandidate(modules=0x0000563786bd5f28, TT=0x0000563786bd5eb8) at GNUstepObjCRuntime.cpp:60:41
    frame llvm#9: 0x00007f2f27946c80 liblldb.so.21.0git`lldb_private::GNUstepObjCRuntime::CreateInstance(process=0x0000563785e1d360, language=eLanguageTypeObjC) at GNUstepObjCRuntime.cpp:87:8
    frame llvm#10: 0x00007f2f2746fca5 liblldb.so.21.0git`lldb_private::LanguageRuntime::FindPlugin(process=0x0000563785e1d360, language=eLanguageTypeObjC) at LanguageRuntime.cpp:210:36
    frame llvm#11: 0x00007f2f2742c9e3 liblldb.so.21.0git`lldb_private::Process::GetLanguageRuntime(this=0x0000563785e1d360, language=eLanguageTypeObjC) at Process.cpp:1516:9
    ...
    frame llvm#21: 0x00007f2f2750b5cc liblldb.so.21.0git`lldb_private::Thread::GetSelectedFrame(this=0x0000563785e064d0, select_most_relevant=DoNoSelectMostRelevantFrame) at Thread.cpp:274:48
    frame llvm#22: 0x00007f2f273f9957 liblldb.so.21.0git`lldb_private::ExecutionContextRef::SetTargetPtr(this=0x00007f2f0f193778, target=0x0000563786bd5be0, adopt_selected=true) at ExecutionContext.cpp:525:32
    frame llvm#23: 0x00007f2f273f9714 liblldb.so.21.0git`lldb_private::ExecutionContextRef::ExecutionContextRef(this=0x00007f2f0f193778, target=0x0000563786bd5be0, adopt_selected=true) at ExecutionContext.cpp:413:3
    frame llvm#24: 0x00007f2f270e80af liblldb.so.21.0git`lldb_private::Debugger::GetSelectedExecutionContext(this=0x0000563785d83bc0) at Debugger.cpp:1225:23
    frame llvm#25: 0x00007f2f271bb7fd liblldb.so.21.0git`lldb_private::Statusline::Redraw(this=0x0000563785d83f30, update=true) at Statusline.cpp:136:41
    ...
* thread #1, name = 'lldb', stop reason = signal SIGSTOP
  * frame #0: 0x00007f2f1e2973dc libc.so.6`futex_wait(private=0, expected=2, futex_word=0x0000563785e1dd98) at futex-internal.h:146:13
   /*... a bunch of mutex related bt ... */    
   liblldb.so.21.0git`std::lock_guard<std::recursive_mutex>::lock_guard(this=0x00007ffe62be0488, __m=0x0000563785e1dd98) at std_mutex.h:229:19
    frame llvm#8: 0x00007f2f2742c8d1 liblldb.so.21.0git`lldb_private::Process::GetLanguageRuntime(this=0x0000563785e1d360, language=eLanguageTypeC_plus_plus) at Process.cpp:1510:41
    frame llvm#9: 0x00007f2f2743c46f liblldb.so.21.0git`lldb_private::Process::ModulesDidLoad(this=0x0000563785e1d360, module_list=0x00007ffe62be06a0) at Process.cpp:6082:36
    ...
    frame llvm#13: 0x00007f2f2715cf03 liblldb.so.21.0git`lldb_private::ModuleList::AppendImpl(this=0x0000563786bd5f28, module_sp=ptr = 0x563785cec560, use_notifier=true) at ModuleList.cpp:246:19
    frame llvm#14: 0x00007f2f2715cf4c liblldb.so.21.0git`lldb_private::ModuleList::Append(this=0x0000563786bd5f28, module_sp=ptr = 0x563785cec560, notify=true) at ModuleList.cpp:251:3
    ...
    frame llvm#19: 0x00007f2f274349b3 liblldb.so.21.0git`lldb_private::Process::ConnectRemote(this=0x0000563785e1d360, remote_url=(Data = "connect://localhost:1234", Length = 24)) at Process.cpp:3250:9
    frame llvm#20: 0x00007f2f27411e0e liblldb.so.21.0git`lldb_private::Platform::DoConnectProcess(this=0x0000563785c59990, connect_url=(Data = "connect://localhost:1234", Length = 24), plugin_name=(Data = "gdb-remote", Length = 10), debugger=0x0000563785d83bc0, stream=0x00007ffe62be3128, target=0x0000563786bd5be0, error=0x00007ffe62be1ca0) at Platform.cpp:1926:23
```

## Test Plan:
Built a hello world a.out
Run server in one terminal:
```
~/llvm/build/Debug/bin/lldb-server g :1234 a.out
```
Run client in another terminal
```
~/llvm/build/Debug/bin/lldb -o "gdb-remote 1234" -o "b hello.cc:3"
```

Before:
Client hangs indefinitely
```
~/llvm/build/Debug/bin/lldb -o "gdb-remote 1234" -o "b main"
(lldb) gdb-remote 1234

^C^C
```

After:
```
~/llvm/build/Debug/bin/lldb -o "gdb-remote 1234" -o "b hello.cc:3"
(lldb) gdb-remote 1234
Process 837068 stopped
* thread #1, name = 'a.out', stop reason = signal SIGSTOP
    frame #0: 0x00007ffff7fe4a60
ld-linux-x86-64.so.2`_start:
->  0x7ffff7fe4a60 <+0>: movq   %rsp, %rdi
    0x7ffff7fe4a63 <+3>: callq  0x7ffff7fe5780 ; _dl_start at rtld.c:522:1

ld-linux-x86-64.so.2`_dl_start_user:
    0x7ffff7fe4a68 <+0>: movq   %rax, %r12
    0x7ffff7fe4a6b <+3>: movl   0x18067(%rip), %eax ; _dl_skip_args
(lldb) b hello.cc:3
Breakpoint 1: where = a.out`main + 15 at hello.cc:4:13, address = 0x00005555555551bf
(lldb) c
Process 837068 resuming
Process 837068 stopped
* thread #1, name = 'a.out', stop reason = breakpoint 1.1
    frame #0: 0x00005555555551bf a.out`main at hello.cc:4:13
   1   	#include <iostream>
   2
   3   	int main() {
-> 4   	  std::cout << "Hello World" << std::endl;
   5   	  return 0;
   6   	}
```
justinfargnoli pushed a commit that referenced this pull request Aug 18, 2025
M68k's SETCC instruction (`scc`) distinctly fills the destination byte
with all 1s. If boolean contents are set to `ZeroOrOneBooleanContent`,
LLVM can mistakenly think the destination holds `0x01` instead of `0xff`
and emit broken code as a result. This change corrects the boolean
content type to `ZeroOrNegativeOneBooleanContent`.

For example, this IR:

```llvm
define dso_local signext range(i8 0, 2) i8 @testBool(i32 noundef %a) local_unnamed_addr #0 {
entry:
  %cmp = icmp eq i32 %a, 4660
  %. = zext i1 %cmp to i8
  ret i8 %.
}
```

would previously build as:

```asm
testBool:                               ; @testBool
	cmpi.l	llvm#4660, (4,%sp)
	seq	%d0
	and.l	llvm#255, %d0
	rts
```

Notice the `zext` is erroneously not clearing the low bits, and thus the
register returns with 255 instead of 1. This patch fixes the issue:

```asm
testBool:                               ; @testBool
	cmpi.l	llvm#4660, (4,%sp)
	seq	%d0
	and.l	#1, %d0
	rts
```

Most of the tests containing `scc` suffered from the same value error as
described above, so those tests have been updated to match the new
output (which also logically corrects them).
justinfargnoli pushed a commit that referenced this pull request Aug 18, 2025
## Problem

When the new setting

```
set target.parallel-module-load true
```
was added, lldb began fetching modules from the devices from multiple
threads simultaneously. This caused crashes of lldb when debugging on
android devices.

The top of the stack in the crash look something like this:
```
#0 0x0000555aaf2b27fe llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/llvm/bin/lldb-dap+0xb87fe)
 #1 0x0000555aaf2b0a99 llvm::sys::RunSignalHandlers() (/opt/llvm/bin/lldb-dap+0xb6a99)
 llvm#2 0x0000555aaf2b2fda SignalHandler(int, siginfo_t*, void*) (/opt/llvm/bin/lldb-dap+0xb8fda)
 llvm#3 0x00007f9c02444560 __restore_rt /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/signal/../sysdeps/unix/sysv/linux/libc_sigaction.c:13:0
 llvm#4 0x00007f9c04ea7707 lldb_private::ConnectionFileDescriptor::Disconnect(lldb_private::Status*) (usr/bin/../lib/liblldb.so.15+0x22a7707)
 llvm#5 0x00007f9c04ea5b41 lldb_private::ConnectionFileDescriptor::~ConnectionFileDescriptor() (usr/bin/../lib/liblldb.so.15+0x22a5b41)
 llvm#6 0x00007f9c04ea5c1e lldb_private::ConnectionFileDescriptor::~ConnectionFileDescriptor() (usr/bin/../lib/liblldb.so.15+0x22a5c1e)
 llvm#7 0x00007f9c052916ff lldb_private::platform_android::AdbClient::SyncService::Stat(lldb_private::FileSpec const&, unsigned int&, unsigned int&, unsigned int&) (usr/bin/../lib/liblldb.so.15+0x26916ff)
 llvm#8 0x00007f9c0528b9dc lldb_private::platform_android::PlatformAndroid::GetFile(lldb_private::FileSpec const&, lldb_private::FileSpec const&) (usr/bin/../lib/liblldb.so.15+0x268b9dc)
```
Our workaround was to set `set target.parallel-module-load ` to `false`
to avoid the crash.

## Background

PlatformAndroid creates two different classes with one stateful adb
connection shared between the two -- one through AdbClient and another
through AdbClient::SyncService. The connection management and state is
complex, and seems to be responsible for the segfault we are seeing. The
AdbClient code resets these connections at times, and re-establishes
connections if they are not active. Similarly, PlatformAndroid caches
its SyncService, which uses an AdbClient class, but the SyncService puts
its connection into a different 'sync' state that is incompatible with a
standard connection.

## Changes in this diff

* This diff refactors the code to (hopefully) have clearer ownership of
the connection, clearer separation of AdbClient and SyncService by
making a new class for clearer separations of concerns, called
AdbSyncService.
* New unit tests are added
* Additional logs were added (see
llvm#145382 (comment)
for details)
justinfargnoli pushed a commit that referenced this pull request Aug 18, 2025
…namic (llvm#153420)

Canonicalizing the following IR:

```
func.func @mul_zero_dynamic_nofold(%arg0: tensor<?x17xf32>) -> tensor<?x17xf32> {
  %0 = "tosa.const"() <{values = dense<0.000000e+00> : tensor<1x1xf32>}> : () -> tensor<1x1xf32>
  %1 = "tosa.const"() <{values = dense<0> : tensor<1xi8>}> : () -> tensor<1xi8>
  %2 = tosa.mul %arg0, %0, %1 : (tensor<?x17xf32>, tensor<1x1xf32>, tensor<1xi8>) -> tensor<?x17xf32>
  return %2 : tensor<?x17xf32>
}
```

resulted in a crash

```
#0 0x000056513187e8db backtrace (./build-release/bin/mlir-opt+0x9d698db)                                                                                                                                                                                                                                                                                                                   
 #1 0x0000565131b17737 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /local-ssd/sayans/Softwares/llvm-repo/llvm-project-latest/llvm/lib/Support/Unix/Signals.inc:838:8                                                                                                                                                                                                                
 llvm#2 0x0000565131b187f3 PrintStackTraceSignalHandler(void*) /local-ssd/sayans/Softwares/llvm-repo/llvm-project-latest/llvm/lib/Support/Unix/Signals.inc:918:1                                                                                                                                                                                                                                
 llvm#3 0x0000565131b18c30 llvm::sys::RunSignalHandlers() /local-ssd/sayans/Softwares/llvm-repo/llvm-project-latest/llvm/lib/Support/Signals.cpp:105:18                                                                                                                                                                                                                                         
 llvm#4 0x0000565131b18c30 SignalHandler(int, siginfo_t*, void*) /local-ssd/sayans/Softwares/llvm-repo/llvm-project-latest/llvm/lib/Support/Unix/Signals.inc:409:3                                                                                                                                                                                                                              
 llvm#5 0x00007f2e4165b050 (/lib/x86_64-linux-gnu/libc.so.6+0x3c050)                                                                                                                                                                                                                                                                                                                            
 llvm#6 0x00007f2e416a9eec __pthread_kill_implementation ./nptl/pthread_kill.c:44:76                                                                                                                                                                                                                                                                                                            
 llvm#7 0x00007f2e4165afb2 raise ./signal/../sysdeps/posix/raise.c:27:6                                                                                                                                                                                                                                                                                                                         
 llvm#8 0x00007f2e41645472 abort ./stdlib/abort.c:81:7                                                                                                                                                                                                                                                                                                                                          
 llvm#9 0x00007f2e41645395 _nl_load_domain ./intl/loadmsgcat.c:1177:9                                                                                                                                                                                                                                                                                                                           
llvm#10 0x00007f2e41653ec2 (/lib/x86_64-linux-gnu/libc.so.6+0x34ec2)                                                                                                                                                                                                                                                                                                                            
llvm#11 0x00005651443ec4ba mlir::DenseIntOrFPElementsAttr::getRaw(mlir::ShapedType, llvm::ArrayRef<char>) /local-ssd/sayans/Softwares/llvm-repo/llvm-project-latest/mlir/lib/IR/BuiltinAttributes.cpp:1361:3                                                                                                                                                                                    
llvm#12 0x00005651443f1209 mlir::DenseElementsAttr::resizeSplat(mlir::ShapedType) /local-ssd/sayans/Softwares/llvm-repo/llvm-project-latest/mlir/lib/IR/BuiltinAttributes.cpp:0:10                                                                                                                                                                                                              
llvm#13 0x000056513f76f2b6 mlir::tosa::MulOp::fold(mlir::tosa::MulOpGenericAdaptor<llvm::ArrayRef<mlir::Attribute>>) /local-ssd/sayans/Softwares/llvm-repo/llvm-project-latest/mlir/lib/Dialect/Tosa/IR/TosaCanonicalizations.cpp:0:0
```

from the folder for `tosa::mul` since the zero value was being reshaped
to `?x17` size which isn't supported. AFAIK, `tosa.const` requires all
dimensions to be static. So in this case, the fix is to not to fold the
op.
justinfargnoli pushed a commit that referenced this pull request Aug 22, 2025
…vm#153560)

Fixes llvm#153157

The proposed solution has been discussed here
(llvm#153157 (comment))

This is what we would be seeing now 

```
base) anutosh491@Anutoshs-MacBook-Air bin % ./lldb /Users/anutosh491/work/xeus-cpp/a.out
(lldb) target create "/Users/anutosh491/work/xeus-cpp/a.out"
Current executable set to '/Users/anutosh491/work/xeus-cpp/a.out' (arm64).
(lldb) b main
Breakpoint 1: where = a.out`main, address = 0x0000000100003f90
(lldb) r
Process 71227 launched: '/Users/anutosh491/work/xeus-cpp/a.out' (arm64)
Process 71227 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
    frame #0: 0x0000000100003f90 a.out`main
a.out`main:
->  0x100003f90 <+0>:  sub    sp, sp, #0x10
    0x100003f94 <+4>:  str    wzr, [sp, #0xc]
    0x100003f98 <+8>:  str    w0, [sp, #0x8]
    0x100003f9c <+12>: str    x1, [sp]
(lldb) expression --repl -l c -- 
  1> 1 + 1
(int) $0 = 2
  2> 2 + 2
(int) $1 = 4
```

```
base) anutosh491@Anutoshs-MacBook-Air bin % ./lldb /Users/anutosh491/work/xeus-cpp/a.out
(lldb) target create "/Users/anutosh491/work/xeus-cpp/a.out"
Current executable set to '/Users/anutosh491/work/xeus-cpp/a.out' (arm64).
(lldb) b main
Breakpoint 1: where = a.out`main, address = 0x0000000100003f90
(lldb) r
Process 71355 launched: '/Users/anutosh491/work/xeus-cpp/a.out' (arm64)
Process 71355 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
    frame #0: 0x0000000100003f90 a.out`main
a.out`main:
->  0x100003f90 <+0>:  sub    sp, sp, #0x10
    0x100003f94 <+4>:  str    wzr, [sp, #0xc]
    0x100003f98 <+8>:  str    w0, [sp, #0x8]
    0x100003f9c <+12>: str    x1, [sp]
(lldb) expression --repl -l c -- 3 + 3
Warning: trailing input is ignored in --repl mode
  1> 1 + 1
(int) $0 = 2
```
justinfargnoli pushed a commit that referenced this pull request Aug 22, 2025
This can happen when JIT code is run, and we can't symbolize those
frames, but they should remain numbered in the stack. An example
spidermonkey trace:

```
    #0 0x564ac90fb80f  (/builds/worker/dist/bin/js+0x240e80f) (BuildId: 5d053c76aad4cfbd08259f8832e7ac78bbeeab58)
    #1 0x564ac9223a64  (/builds/worker/dist/bin/js+0x2536a64) (BuildId: 5d053c76aad4cfbd08259f8832e7ac78bbeeab58)
    llvm#2 0x564ac922316f  (/builds/worker/dist/bin/js+0x253616f) (BuildId: 5d053c76aad4cfbd08259f8832e7ac78bbeeab58)
    llvm#3 0x564ac9eac032  (/builds/worker/dist/bin/js+0x31bf032) (BuildId: 5d053c76aad4cfbd08259f8832e7ac78bbeeab58)
    llvm#4 0x0dec477ca22e  (<unknown module>)
```

Without this change, the following symbolization is output:

```
    #0 0x55a6d72f980f in MOZ_CrashSequence /builds/worker/workspace/obj-build/dist/include/mozilla/Assertions.h:248:3
    #1 0x55a6d72f980f in Crash(JSContext*, unsigned int, JS::Value*) /builds/worker/checkouts/gecko/js/src/shell/js.cpp:4223:5
    llvm#2 0x55a6d7421a64 in CallJSNative(JSContext*, bool (*)(JSContext*, unsigned int, JS::Value*), js::CallReason, JS::CallArgs const&) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:501:13
    llvm#3 0x55a6d742116f in js::InternalCallOrConstruct(JSContext*, JS::CallArgs const&, js::MaybeConstruct, js::CallReason) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:597:12
    llvm#4 0x55a6d80aa032 in js::jit::DoCallFallback(JSContext*, js::jit::BaselineFrame*, js::jit::ICFallbackStub*, unsigned int, JS::Value*, JS::MutableHandle<JS::Value>) /builds/worker/checkouts/gecko/js/src/jit/BaselineIC.cpp:1705:10
    llvm#4 0x2c803bd8f22e  (<unknown module>)
```

The last frame has a duplicate number. With this change the numbering is
correct:

```
    #0 0x5620c58ec80f in MOZ_CrashSequence /builds/worker/workspace/obj-build/dist/include/mozilla/Assertions.h:248:3
    #1 0x5620c58ec80f in Crash(JSContext*, unsigned int, JS::Value*) /builds/worker/checkouts/gecko/js/src/shell/js.cpp:4223:5
    llvm#2 0x5620c5a14a64 in CallJSNative(JSContext*, bool (*)(JSContext*, unsigned int, JS::Value*), js::CallReason, JS::CallArgs const&) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:501:13
    llvm#3 0x5620c5a1416f in js::InternalCallOrConstruct(JSContext*, JS::CallArgs const&, js::MaybeConstruct, js::CallReason) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:597:12
    llvm#4 0x5620c669d032 in js::jit::DoCallFallback(JSContext*, js::jit::BaselineFrame*, js::jit::ICFallbackStub*, unsigned int, JS::Value*, JS::MutableHandle<JS::Value>) /builds/worker/checkouts/gecko/js/src/jit/BaselineIC.cpp:1705:10
    llvm#5 0x349f24c7022e  (<unknown module>)
```
justinfargnoli pushed a commit that referenced this pull request Aug 22, 2025
…gic (llvm#153086)

Given the test case:

```llvm
define fastcc i16 @testbtst(i16 %a) nounwind {
  entry:
    switch i16 %a, label %no [
      i16 11, label %yes
      i16 10, label %yes
      i16 9, label %yes
      i16 4, label %yes
      i16 3, label %yes
      i16 2, label %yes
    ]

  yes:
    ret i16 1

  no:
    ret i16 0
}
```

We currently get this result:

```asm
testbtst:                               ; @testbtst
; %bb.0:                                ; %entry
	move.l	%d0, %d1
	and.l	llvm#65535, %d1
	sub.l	llvm#11, %d1
	bhi	.LBB0_3
; %bb.1:                                ; %entry
	and.l	llvm#65535, %d0
	move.l	llvm#3612, %d1
	btst	%d0, %d1
	bne	.LBB0_3        ; <------- Erroneous condition
; %bb.2:                                ; %yes
	moveq	#1, %d0
	rts
.LBB0_3:                                ; %no
	moveq	#0, %d0
	rts
```

The cause of this is a line that explicitly reverses the `btst`
condition code. But on M68k, `btst` sets condition codes the same as
`and` with a bitmask, meaning `EQ` indicates failure (bit is zero) and
not success, so the condition does not need to be reversed.

In my testing, I've only been able to get switch statements to lower to
`btst`, so I wasn't able to explicitly test other options for lowering.
But (if possible to trigger) I believe they have the same logical error.
For example, in `LowerAndToBTST()`, a comment specifies that it's
lowering a case where the `and` result is compared against zero, which
means the corresponding `btst` condition should also not be reversed.

This patch simply flips the ternary expression in
`getBitTestCondition()` to match the ISD condition code with the same
M68k code, instead of the opposite.
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