Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: ebc19a3dc75e891b5916de93914ec5771ab91fbc
https://github.com/WebKit/WebKit/commit/ebc19a3dc75e891b5916de93914ec5771ab91fbc
Author: Keith Miller <[email protected]>
Date: 2026-03-05 (Thu, 05 Mar 2026)
Changed paths:
M Source/JavaScriptCore/assembler/LinkBuffer.h
M Source/JavaScriptCore/dfg/DFGSpeculativeJIT32_64.cpp
M Source/JavaScriptCore/dfg/DFGSpeculativeJIT64.cpp
M Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp
M Source/JavaScriptCore/jit/JIT.cpp
M Source/JavaScriptCore/jit/JITDisassembler.cpp
M Source/JavaScriptCore/jit/JITDisassembler.h
M Source/JavaScriptCore/lol/LOLJIT.cpp
M Source/JavaScriptCore/runtime/Options.cpp
Log Message:
-----------
[JSC] Bytecode profiler should include JIT comments
https://bugs.webkit.org/show_bug.cgi?id=309270
rdar://171815352
Reviewed by Yijia Huang and Dan Hecht.
Right now we just get the raw disassembly but it's nicer to see the JIT
comments so the assembly is easier to read. I also annotated the
profiling emitted assembly so it's easier to decern and ignore when
reading.
Additionally, add m_codeStart/End to reportToProfiler so that Baseline
logs immediates to the profile as well.
After this change, profile disassembly looks like:
```
0 0/0/0/0 [ 30] construct
dst:loc6, callee:loc6, argc:2, argv:16, valueProfile:2
0 0/0/0/0 <496>
0x118658630: mov x17, #0x4120; Execution trace start
0 0/0/0/0 <500>
0x118658634: movk x17, #0x209, lsl #0x10
0 0/0/0/0 <504>
0x118658638: movk x17, #0x1, lsl #0x20 -> 0x102094120
0 0/0/0/0 <508>
0x11865863c: ldr x16, [x17, xzr]
0 0/0/0/0 <512>
0x118658640: add x16, x16, #0x1
0 0/0/0/0 <516>
0x118658644: stur x16, [x17]
0 0/0/0/0 <520>
0x118658648: sub sp, fp, #0x70; First non-trace instruction
0 0/0/0/0 <524>
0x11865864c: orr w16, wzr, #0x2
0 0/0/0/0 <528>
0x118658650: stur w16, [sp, #0x10]
0 0/0/0/0 <532>
0x118658654: orr w16, wzr, #0x1e
0 0/0/0/0 <536>
0x118658658: stur w16, [fp, #0x24]
0 0/0/0/0 <540>
0x11865865c: ldur x0, [fp, #-0x38]
0 0/0/0/0 <544>
0x118658660: stur x0, [sp, #0x8]
0 0/0/0/0 <548>
0x118658664: add x2, x25, #0x68
0 0/0/0/0 <552>
0x118658668: ldur x5, [x2, #0x20]
0 0/0/0/0 <556>
0x11865866c: ldur x16, [x2, #0x28]
0 0/0/0/0 <560>
0x118658670: cmp x16, x0
0 0/0/0/0 <564>
0x118658674: b.eq 0x11865868c -> <588>
0 0/0/0/0 <568>
0x118658678: tbnz w16, #0, 0x11865868c -> <588>
0 0/0/0/0 <572>
0x11865867c: mov x5, #0x100
0 0/0/0/0 <576>
0x118658680: movk x5, #0x1866, lsl #0x10
0 0/0/0/0 <580>
0x118658684: movk x5, #0x1, lsl #0x20
0 0/0/0/0 <584>
0x118658688: movk x5, #0xd86e, lsl #0x30 -> 0xd86e000118660100 JIT PC
0 0/0/0/0 <588>
0x11865868c: ldur x16, [x2, #0x18]
0 0/0/0/0 <592>
0x118658690: stur x16, [sp]
0 0/0/0/0 <596>
0x118658694: mov lr, #0x593 -> 0x593 JSEntryPtrTag ?
0 0/0/0/0 <600>
0x118658698: blrab x5, lr
0 0/0/0/0 <604>
0x11865869c: sub sp, fp, #0x80
0 0/0/0/0 <608>
0x1186586a0: stur x0, [x25, #-0x30]
0 0/0/0/0 <612>
0x1186586a4: stur x0, [fp, #-0x38]
```
No new tests, no user observable change.
Canonical link: https://commits.webkit.org/308738@main
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