Some improvements to DFG and FTL dumps to improve readability and sea…

…rchability. https://bugs.webkit.org/show_bug.cgi?id=207024 Reviewed by Saam Barati. This patch applies the following changes: 1. Prefix Air and B2 dumps with a tierName prefix. The tierName prefix strings are as follows: "FTL ", "DFG ", "b3 ", "Air ", "asm " The choice to use a lowercase "b3" and "asm" with upper case "Air" is deliberate because I found this combination to be easier to read and scan as prefixes of the dump lines. See dump samples below. 2. Make DFG node IDs consistently expressed as D@<node index> e.g. D@104. The definition of the node will be the id followed by a colon e.g. D@104: This makes it easy to search references to this node anywhere in the dump. Make B3 nodes expressed as b@<node index> e.g. b@542. This also makes it searchable since there's now no ambiguity between b@542 and D@542. The choice to use a lowercase "b" and an uppercase "D" is intentional because "b@542" and "d@542" looks too similar, and I prefer to not use too much uppercase. Plus this makes the node consistent in capitalization with the tierName prefixes above of "b3 " and "DFG " respectively. Here's a sample of what the dumps now look like: DFG graph dump: <code> ... 6 55: <-- foo#DFndCW:<0x62d0000b8140, bc#65, Call, known callee: Object: 0x62d000035920 with butterfly 0x0 (Structure %AN:Function), StructureID: 12711, numArgs+this = 1, numFixup = 0, stackOffset = -16 (loc0 maps to loc16)> 3 6 55: D@79:< 3:-> ArithAdd(Int32:Kill:D@95, Int32:D@42, Int32|PureNum|UseAsOther, Int32, CheckOverflow, Exits, bc#71, ExitValid) 4 6 55: D@3:<!0:-> KillStack(MustGen, loc7, W:Stack(loc7), ClobbersExit, bc#71, ExitInvalid) 5 6 55: D@85:<!0:-> MovHint(Check:Untyped:D@79, MustGen, loc7, W:SideState, ClobbersExit, bc#71, ExitInvalid) 6 6 55: D@102:< 1:-> CompareLess(Int32:D@79, Int32:D@89, Boolean|UseAsOther, Bool, Exits, bc#74, ExitValid) 7 6 55: D@104:<!0:-> Branch(KnownBoolean:Kill:D@102, MustGen, T:#1/w:10.000000, F:#7/w:1.000000, W:SideState, bc#74, ExitInvalid) ... </code> B3 graph dump: <code> ... b3 BB#14: ; frequency = 10.000000 b3 Predecessors: #13 b3 Int32 b@531 = CheckAdd(b@10:WarmAny, $1(b@1):WarmAny, b@64:ColdAny, b@10:ColdAny, generator = 0x606000022e80, earlyClobbered = [], lateClobbered = [], usedRegisters = [], ExitsSideways|Reads:Top, D@79) b3 Int32 b@539 = LessThan(b@531, $100(b@578), D@102) b3 Void b@542 = Branch(b@539, Terminal, D@104) b3 Successors: Then:#2, Else:#15 ... </code> Air graph dump: <code> ... Air BB#5: ; frequency = 10.000000 Air Predecessors: #4 Air Move -96(%rbp), %rax, b@531 Air Patch &BranchAdd32(3,ForceLateUseUnlessRecoverable)3, Overflow, $1, %rax, -104(%rbp), -96(%rbp), b@531 Air Branch32 LessThan, %rax, $100, b@542 Air Successors: #1, #6 ... </code> FTL disassembly dump: <code> ... Air BB#5: ; frequency = 10.000000 Air Predecessors: #4 DFG D@42:< 2:-> JSConstant(JS|PureInt, Int32, Int32: 1, bc#0, ExitInvalid) DFG D@79:< 3:-> ArithAdd(Int32:Kill:D@95, Int32:D@42, Int32|PureNum|UseAsOther, Int32, CheckOverflow, Exits, bc#71, ExitValid) b3 Int32 b@1 = Const32(1) b3 Int32 b@531 = CheckAdd(b@10:WarmAny, $1(b@1):WarmAny, b@64:ColdAny, b@10:ColdAny, generator = 0x606000022e80, earlyClobbered = [], lateClobbered = [], usedRegisters = [%rax, %rbx, %rbp, %r12], ExitsSideways|Reads:Top, D@79) Air Move -96(%rbp), %rax, b@531 asm 0x4576b9c04712: mov -0x60(%rbp), %rax Air Patch &BranchAdd32(3,ForceLateUseUnlessRecoverable)3, Overflow, $1, %rax, -104(%rbp), -96(%rbp), b@531 asm 0x4576b9c04716: inc %eax asm 0x4576b9c04718: jo 0x4576b9c04861 DFG D@89:< 1:-> JSConstant(JS|PureNum|UseAsOther, NonBoolInt32, Int32: 100, bc#0, ExitInvalid) DFG D@102:< 1:-> CompareLess(Int32:D@79, Int32:D@89, Boolean|UseAsOther, Bool, Exits, bc#74, ExitValid) DFG D@104:<!0:-> Branch(KnownBoolean:Kill:D@102, MustGen, T:#1/w:10.000000, F:#7/w:1.000000, W:SideState, bc#74, ExitInvalid) b3 Int32 b@578 = Const32(100, D@89) b3 Int32 b@539 = LessThan(b@531, $100(b@578), D@102) b3 Void b@542 = Branch(b@539, Terminal, D@104) Air Branch32 LessThan, %rax, $100, b@542 asm 0x4576b9c0471e: cmp $0x64, %eax asm 0x4576b9c04721: jl 0x4576b9c0462f Air Successors: #1, #6 ... </code> * b3/B3BasicBlock.cpp: (JSC::B3::BasicBlock::deepDump const): * b3/B3Common.cpp: * b3/B3Common.h: * b3/B3Generate.cpp: (JSC::B3::generateToAir): * b3/B3Procedure.cpp: (JSC::B3::Procedure::dump const): * b3/B3Value.cpp: * b3/air/AirBasicBlock.cpp: (JSC::B3::Air::BasicBlock::deepDump const): (JSC::B3::Air::BasicBlock::dumpHeader const): (JSC::B3::Air::BasicBlock::dumpFooter const): * b3/air/AirCode.cpp: (JSC::B3::Air::Code::dump const): * b3/air/AirCode.h: * b3/air/AirDisassembler.cpp: (JSC::B3::Air::Disassembler::dump): * b3/air/AirGenerate.cpp: (JSC::B3::Air::prepareForGeneration): * dfg/DFGCommon.cpp: * dfg/DFGCommon.h: * dfg/DFGGraph.cpp: (JSC::DFG::Graph::dump): (JSC::DFG::Graph::dumpBlockHeader): * dfg/DFGNode.cpp: (WTF::printInternal): * ftl/FTLCompile.cpp: (JSC::FTL::compile): * ftl/FTLCompile.h: * ftl/FTLState.cpp: (JSC::FTL::State::State): git-svn-id: http://svn.webkit.org/repository/webkit/trunk@255482 268f45cc-cd09-0410-ab3c-d52691b4dbfc
haiku · Jan 31, 2020 · f7af673 · f7af673
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diff --git a/Source/JavaScriptCore/ChangeLog b/Source/JavaScriptCore/ChangeLog
@@ -1,3 +1,132 @@
+2020-01-30  Mark Lam  <mark.lam@apple.com>
+
+        Some improvements to DFG and FTL dumps to improve readability and searchability.
+        https://bugs.webkit.org/show_bug.cgi?id=207024
+
+        Reviewed by Saam Barati.
+
+        This patch applies the following changes:
+
+        1. Prefix Air and B2 dumps with a tierName prefix.
+           The tierName prefix strings are as follows:
+
+               "FTL ", "DFG ", "b3  ", "Air ", "asm "
+
+           The choice to use a lowercase "b3" and "asm" with upper case "Air" is
+           deliberate because I found this combination to be easier to read and scan as
+           prefixes of the dump lines.  See dump samples below.
+
+        2. Make DFG node IDs consistently expressed as D@<node index> e.g. D@104.
+           The definition of the node will be the id followed by a colon e.g. D@104:
+           This makes it easy to search references to this node anywhere in the dump.
+
+           Make B3 nodes expressed as b@<node index> e.g. b@542.
+           This also makes it searchable since there's now no ambiguity between b@542 and
+           D@542.
+
+           The choice to use a lowercase "b" and an uppercase "D" is intentional because
+           "b@542" and "d@542" looks too similar, and I prefer to not use too much
+           uppercase.  Plus this makes the node consistent in capitalization with the
+           tierName prefixes above of "b3  " and "DFG " respectively.
+
+        Here's a sample of what the dumps now look like:
+
+        DFG graph dump:
+        <code>
+            ...
+                 6 55:   <-- foo#DFndCW:<0x62d0000b8140, bc#65, Call, known callee: Object: 0x62d000035920 with butterfly 0x0 (Structure %AN:Function), StructureID: 12711, numArgs+this = 1, numFixup = 0, stackOffset = -16 (loc0 maps to loc16)>
+              3  6 55:   D@79:< 3:->    ArithAdd(Int32:Kill:D@95, Int32:D@42, Int32|PureNum|UseAsOther, Int32, CheckOverflow, Exits, bc#71, ExitValid)
+              4  6 55:    D@3:<!0:->    KillStack(MustGen, loc7, W:Stack(loc7), ClobbersExit, bc#71, ExitInvalid)
+              5  6 55:   D@85:<!0:->    MovHint(Check:Untyped:D@79, MustGen, loc7, W:SideState, ClobbersExit, bc#71, ExitInvalid)
+              6  6 55:  D@102:< 1:->    CompareLess(Int32:D@79, Int32:D@89, Boolean|UseAsOther, Bool, Exits, bc#74, ExitValid)
+              7  6 55:  D@104:<!0:->    Branch(KnownBoolean:Kill:D@102, MustGen, T:#1/w:10.000000, F:#7/w:1.000000, W:SideState, bc#74, ExitInvalid)
+            ...
+        </code>
+
+        B3 graph dump:
+        <code>
+            ...
+            b3  BB#14: ; frequency = 10.000000
+            b3    Predecessors: #13
+            b3      Int32 b@531 = CheckAdd(b@10:WarmAny, $1(b@1):WarmAny, b@64:ColdAny, b@10:ColdAny, generator = 0x606000022e80, earlyClobbered = [], lateClobbered = [], usedRegisters = [], ExitsSideways|Reads:Top, D@79)
+            b3      Int32 b@539 = LessThan(b@531, $100(b@578), D@102)
+            b3      Void b@542 = Branch(b@539, Terminal, D@104)
+            b3    Successors: Then:#2, Else:#15
+            ...
+        </code>
+
+        Air graph dump:
+        <code>
+            ...
+            Air BB#5: ; frequency = 10.000000
+            Air   Predecessors: #4
+            Air     Move -96(%rbp), %rax, b@531
+            Air     Patch &BranchAdd32(3,ForceLateUseUnlessRecoverable)3, Overflow, $1, %rax, -104(%rbp), -96(%rbp), b@531
+            Air     Branch32 LessThan, %rax, $100, b@542
+            Air   Successors: #1, #6
+            ...
+        </code>
+
+        FTL disassembly dump:
+        <code>
+            ...
+            Air BB#5: ; frequency = 10.000000
+            Air   Predecessors: #4
+            DFG       D@42:< 2:->   JSConstant(JS|PureInt, Int32, Int32: 1, bc#0, ExitInvalid)
+            DFG       D@79:< 3:->   ArithAdd(Int32:Kill:D@95, Int32:D@42, Int32|PureNum|UseAsOther, Int32, CheckOverflow, Exits, bc#71, ExitValid)
+            b3            Int32 b@1 = Const32(1)
+            b3            Int32 b@531 = CheckAdd(b@10:WarmAny, $1(b@1):WarmAny, b@64:ColdAny, b@10:ColdAny, generator = 0x606000022e80, earlyClobbered = [], lateClobbered = [], usedRegisters = [%rax, %rbx, %rbp, %r12], ExitsSideways|Reads:Top, D@79)
+            Air               Move -96(%rbp), %rax, b@531
+            asm                   0x4576b9c04712: mov -0x60(%rbp), %rax
+            Air               Patch &BranchAdd32(3,ForceLateUseUnlessRecoverable)3, Overflow, $1, %rax, -104(%rbp), -96(%rbp), b@531
+            asm                   0x4576b9c04716: inc %eax
+            asm                   0x4576b9c04718: jo 0x4576b9c04861
+            DFG       D@89:< 1:->   JSConstant(JS|PureNum|UseAsOther, NonBoolInt32, Int32: 100, bc#0, ExitInvalid)
+            DFG      D@102:< 1:->   CompareLess(Int32:D@79, Int32:D@89, Boolean|UseAsOther, Bool, Exits, bc#74, ExitValid)
+            DFG      D@104:<!0:->   Branch(KnownBoolean:Kill:D@102, MustGen, T:#1/w:10.000000, F:#7/w:1.000000, W:SideState, bc#74, ExitInvalid)
+            b3            Int32 b@578 = Const32(100, D@89)
+            b3            Int32 b@539 = LessThan(b@531, $100(b@578), D@102)
+            b3            Void b@542 = Branch(b@539, Terminal, D@104)
+            Air               Branch32 LessThan, %rax, $100, b@542
+            asm                   0x4576b9c0471e: cmp $0x64, %eax
+            asm                   0x4576b9c04721: jl 0x4576b9c0462f
+            Air   Successors: #1, #6
+            ...
+        </code>
+
+        * b3/B3BasicBlock.cpp:
+        (JSC::B3::BasicBlock::deepDump const):
+        * b3/B3Common.cpp:
+        * b3/B3Common.h:
+        * b3/B3Generate.cpp:
+        (JSC::B3::generateToAir):
+        * b3/B3Procedure.cpp:
+        (JSC::B3::Procedure::dump const):
+        * b3/B3Value.cpp:
+        * b3/air/AirBasicBlock.cpp:
+        (JSC::B3::Air::BasicBlock::deepDump const):
+        (JSC::B3::Air::BasicBlock::dumpHeader const):
+        (JSC::B3::Air::BasicBlock::dumpFooter const):
+        * b3/air/AirCode.cpp:
+        (JSC::B3::Air::Code::dump const):
+        * b3/air/AirCode.h:
+        * b3/air/AirDisassembler.cpp:
+        (JSC::B3::Air::Disassembler::dump):
+        * b3/air/AirGenerate.cpp:
+        (JSC::B3::Air::prepareForGeneration):
+        * dfg/DFGCommon.cpp:
+        * dfg/DFGCommon.h:
+        * dfg/DFGGraph.cpp:
+        (JSC::DFG::Graph::dump):
+        (JSC::DFG::Graph::dumpBlockHeader):
+        * dfg/DFGNode.cpp:
+        (WTF::printInternal):
+        * ftl/FTLCompile.cpp:
+        (JSC::FTL::compile):
+        * ftl/FTLCompile.h:
+        * ftl/FTLState.cpp:
+        (JSC::FTL::State::State):
+
 2020-01-30  Yusuke Suzuki  <ysuzuki@apple.com>
 
         [WTF] Remove PackedIntVector

diff --git a/Source/JavaScriptCore/b3/B3BasicBlock.cpp b/Source/JavaScriptCore/b3/B3BasicBlock.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2016 Apple Inc. All rights reserved.
+ * Copyright (C) 2015-2020 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -154,13 +154,13 @@ void BasicBlock::dump(PrintStream& out) const
 
 void BasicBlock::deepDump(const Procedure& proc, PrintStream& out) const
 {
-    out.print("BB", *this, ": ; frequency = ", m_frequency, "\n");
+    out.print(tierName, "BB", *this, ": ; frequency = ", m_frequency, "\n");
     if (predecessors().size())
-        out.print("  Predecessors: ", pointerListDump(predecessors()), "\n");
+        out.print(tierName, "  Predecessors: ", pointerListDump(predecessors()), "\n");
     for (Value* value : *this)
-        out.print("    ", B3::deepDump(proc, value), "\n");
+        out.print(tierName, "    ", B3::deepDump(proc, value), "\n");
     if (!successors().isEmpty()) {
-        out.print("  Successors: ");
+        out.print(tierName, "  Successors: ");
         if (size())
             last()->dumpSuccessors(this, out);
         else

diff --git a/Source/JavaScriptCore/b3/B3Common.cpp b/Source/JavaScriptCore/b3/B3Common.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015 Apple Inc. All rights reserved.
+ * Copyright (C) 2015-2020 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -35,6 +35,8 @@
 
 namespace JSC { namespace B3 {
 
+const char* const tierName = "b3  ";
+
 bool shouldDumpIR(B3CompilationMode mode)
 {
 #if ENABLE(FTL_JIT)

diff --git a/Source/JavaScriptCore/b3/B3Common.h b/Source/JavaScriptCore/b3/B3Common.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2017 Apple Inc. All rights reserved.
+ * Copyright (C) 2015-2020 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -34,6 +34,8 @@
 
 namespace JSC { namespace B3 {
 
+extern const char* const tierName;
+
 enum B3CompilationMode {
     B3Mode,
     AirMode

diff --git a/Source/JavaScriptCore/b3/B3Generate.cpp b/Source/JavaScriptCore/b3/B3Generate.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2018 Apple Inc. All rights reserved.
+ * Copyright (C) 2015-2020 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -74,7 +74,7 @@ void generateToAir(Procedure& procedure)
     TimingScope timingScope("generateToAir");
 
     if (shouldDumpIR(B3Mode) && !shouldDumpIRAtEachPhase(B3Mode)) {
-        dataLog("Initial B3:\n");
+        dataLog(tierName, "Initial B3:\n");
         dataLog(procedure);
     }
 

diff --git a/Source/JavaScriptCore/b3/B3Procedure.cpp b/Source/JavaScriptCore/b3/B3Procedure.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2019 Apple Inc. All rights reserved.
+ * Copyright (C) 2015-2020 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -239,22 +239,22 @@ void Procedure::dump(PrintStream& out) const
             continue;
 
         if (!didPrint) {
-            dataLog("Orphaned values:\n");
+            dataLog(tierName, "Orphaned values:\n");
             didPrint = true;
         }
-        dataLog("    ", deepDump(*this, value), "\n");
+        dataLog(tierName, "    ", deepDump(*this, value), "\n");
     }
     if (hasQuirks())
-        out.print("Has Quirks: True\n");
+        out.print(tierName, "Has Quirks: True\n");
     if (variables().size()) {
-        out.print("Variables:\n");
+        out.print(tierName, "Variables:\n");
         for (Variable* variable : variables())
-            out.print("    ", deepDump(variable), "\n");
+            out.print(tierName, "    ", deepDump(variable), "\n");
     }
     if (stackSlots().size()) {
-        out.print("Stack slots:\n");
+        out.print(tierName, "Stack slots:\n");
         for (StackSlot* slot : stackSlots())
-            out.print("    ", pointerDump(slot), ": ", deepDump(slot), "\n");
+            out.print(tierName, "    ", pointerDump(slot), ": ", deepDump(slot), "\n");
     }
     if (m_byproducts->count())
         out.print(*m_byproducts);

diff --git a/Source/JavaScriptCore/b3/B3Value.cpp b/Source/JavaScriptCore/b3/B3Value.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2017 Apple Inc. All rights reserved.
+ * Copyright (C) 2015-2020 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -51,7 +51,7 @@
 
 namespace JSC { namespace B3 {
 
-const char* const Value::dumpPrefix = "@";
+const char* const Value::dumpPrefix = "b@";
 void DeepValueDump::dump(PrintStream& out) const
 {
     if (m_value)

diff --git a/Source/JavaScriptCore/b3/air/AirBasicBlock.cpp b/Source/JavaScriptCore/b3/air/AirBasicBlock.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2017 Apple Inc. All rights reserved.
+ * Copyright (C) 2015-2020 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -72,21 +72,21 @@ void BasicBlock::deepDump(PrintStream& out) const
 {
     dumpHeader(out);
     for (const Inst& inst : *this)
-        out.print("    ", inst, "\n");
+        out.print(tierName, "    ", inst, "\n");
     dumpFooter(out);
 }
 
 void BasicBlock::dumpHeader(PrintStream& out) const
 {
-    out.print("BB", *this, ": ; frequency = ", m_frequency, "\n");
+    out.print(tierName, "BB", *this, ": ; frequency = ", m_frequency, "\n");
     if (predecessors().size())
-        out.print("  Predecessors: ", pointerListDump(predecessors()), "\n");
+        out.print(tierName, "  Predecessors: ", pointerListDump(predecessors()), "\n");
 }
 
 void BasicBlock::dumpFooter(PrintStream& out) const
 {
     if (successors().size())
-        out.print("  Successors: ", listDump(successors()), "\n");
+        out.print(tierName, "  Successors: ", listDump(successors()), "\n");
 }
 
 BasicBlock::BasicBlock(unsigned index, double frequency)

diff --git a/Source/JavaScriptCore/b3/air/AirCode.cpp b/Source/JavaScriptCore/b3/air/AirCode.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2018 Apple Inc. All rights reserved.
+ * Copyright (C) 2015-2020 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -40,6 +40,8 @@
 
 namespace JSC { namespace B3 { namespace Air {
 
+const char* const tierName = "Air ";
+
 static void defaultPrologueGenerator(CCallHelpers& jit, Code& code)
 {
     jit.emitFunctionPrologue();
@@ -248,26 +250,26 @@ void Code::resetReachability()
 void Code::dump(PrintStream& out) const
 {
     if (!m_entrypoints.isEmpty())
-        out.print("Entrypoints: ", listDump(m_entrypoints), "\n");
+        out.print(tierName, "Entrypoints: ", listDump(m_entrypoints), "\n");
     for (BasicBlock* block : *this)
         out.print(deepDump(block));
     if (stackSlots().size()) {
-        out.print("Stack slots:\n");
+        out.print(tierName, "Stack slots:\n");
         for (StackSlot* slot : stackSlots())
-            out.print("    ", pointerDump(slot), ": ", deepDump(slot), "\n");
+            out.print(tierName, "    ", pointerDump(slot), ": ", deepDump(slot), "\n");
     }
     if (specials().size()) {
-        out.print("Specials:\n");
+        out.print(tierName, "Specials:\n");
         for (Special* special : specials())
-            out.print("    ", deepDump(special), "\n");
+            out.print(tierName, "    ", deepDump(special), "\n");
     }
     if (m_frameSize || m_stackIsAllocated)
-        out.print("Frame size: ", m_frameSize, m_stackIsAllocated ? " (Allocated)" : "", "\n");
+        out.print(tierName, "Frame size: ", m_frameSize, m_stackIsAllocated ? " (Allocated)" : "", "\n");
     if (m_callArgAreaSize)
-        out.print("Call arg area size: ", m_callArgAreaSize, "\n");
+        out.print(tierName, "Call arg area size: ", m_callArgAreaSize, "\n");
     RegisterAtOffsetList calleeSaveRegisters = this->calleeSaveRegisterAtOffsetList();
     if (calleeSaveRegisters.size())
-        out.print("Callee saves: ", calleeSaveRegisters, "\n");
+        out.print(tierName, "Callee saves: ", calleeSaveRegisters, "\n");
 }
 
 unsigned Code::findFirstBlockIndex(unsigned index) const

diff --git a/Source/JavaScriptCore/b3/air/AirCode.h b/Source/JavaScriptCore/b3/air/AirCode.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2018 Apple Inc. All rights reserved.
+ * Copyright (C) 2015-2020 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -63,6 +63,8 @@ typedef SharedTask<WasmBoundsCheckGeneratorFunction> WasmBoundsCheckGenerator;
 typedef void PrologueGeneratorFunction(CCallHelpers&, Code&);
 typedef SharedTask<PrologueGeneratorFunction> PrologueGenerator;
 
+extern const char* const tierName;
+
 // This is an IR that is very close to the bare metal. It requires about 40x more bytes than the
 // generated machine code - for example if you're generating 1MB of machine code, you need about
 // 40MB of Air.

diff --git a/Source/JavaScriptCore/b3/air/AirDisassembler.cpp b/Source/JavaScriptCore/b3/air/AirDisassembler.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017-2018 Apple Inc. All rights reserved.
+ * Copyright (C) 2017-2020 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -105,7 +105,7 @@ void Disassembler::dump(Code& code, PrintStream& out, LinkBuffer& linkBuffer, co
 
     // FIXME: We could be better about various late paths. We can implement
     // this later if we find a strong use for it.
-    out.print("# Late paths\n");
+    out.print(tierName, "# Late paths\n");
     dumpAsmRange(m_latePathStart, m_latePathEnd);
 }
 

diff --git a/Source/JavaScriptCore/b3/air/AirGenerate.cpp b/Source/JavaScriptCore/b3/air/AirGenerate.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2017 Apple Inc. All rights reserved.
+ * Copyright (C) 2015-2020 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -68,7 +68,7 @@ void prepareForGeneration(Code& code)
 
     // If we're doing super verbose dumping, the phase scope of any phase will already do a dump.
     if (shouldDumpIR(AirMode) && !shouldDumpIRAtEachPhase(AirMode)) {
-        dataLog("Initial air:\n");
+        dataLog(tierName, "Initial air:\n");
         dataLog(code);
     }