[webkit-changes] [172777] trunk/Source/JavaScriptCore

Tue, 19 Aug 2014 16:26:51 -0700

Title: [172777] trunk/Source/_javascript_Core
Revision
172777
Author
[email protected]
Date
2014-08-19 16:25:37 -0700 (Tue, 19 Aug 2014)

Log Message

LLInt build should be way faster
https://bugs.webkit.org/show_bug.cgi?id=136085

Reviewed by Geoffrey Garen.
        
This does three things to improve the LLInt build performance. One of them is only for
Xcode for now while the others should benefit all platforms:
        
- Don't exponentially build settings combinations that correspond to being on two backends
  simultaneously. This is by far the biggest win.
        
- Don't generate offset extraction code for backends that aren't supported by the current
  port. This currently only works on Xcode-based ports. This is a relatively small win.
        
- Remove the ALWAYS_ALLOCATE_SLOW option. Each option increases build time, and we haven't
  used this one in a long time. Anyway, setting this option could be emulated by just
  directly hacking the code.
        
This is an enormous speed-up in the LLInt build.

* _javascript_Core.xcodeproj/project.pbxproj: Prune the set of backends that we should consider on Xcode-based platforms.
* llint/LLIntOfflineAsmConfig.h: Remove ALWAYS_ALLOCATE_SLOW
* llint/LowLevelInterpreter.asm: Remove ALWAYS_ALLOCATE_SLOW
* offlineasm/backends.rb: Add infrastructure for reasoning about valid backends.
* offlineasm/generate_offset_extractor.rb: Allow the client to specify a filtered set of valid backends.
* offlineasm/settings.rb: Improve the construction of settings combinations so that it doesn't traverse the enourmous set of obviously invalid multi-backend combinations. Also glue into support for valid backends.

Modified Paths

Diff

Modified: trunk/Source/_javascript_Core/ChangeLog (172776 => 172777)


--- trunk/Source/_javascript_Core/ChangeLog	2014-08-19 23:20:37 UTC (rev 172776)
+++ trunk/Source/_javascript_Core/ChangeLog	2014-08-19 23:25:37 UTC (rev 172777)
@@ -1,5 +1,34 @@
 2014-08-19  Filip Pizlo  <[email protected]>
 
+        LLInt build should be way faster
+        https://bugs.webkit.org/show_bug.cgi?id=136085
+
+        Reviewed by Geoffrey Garen.
+        
+        This does three things to improve the LLInt build performance. One of them is only for
+        Xcode for now while the others should benefit all platforms:
+        
+        - Don't exponentially build settings combinations that correspond to being on two backends
+          simultaneously. This is by far the biggest win.
+        
+        - Don't generate offset extraction code for backends that aren't supported by the current
+          port. This currently only works on Xcode-based ports. This is a relatively small win.
+        
+        - Remove the ALWAYS_ALLOCATE_SLOW option. Each option increases build time, and we haven't
+          used this one in a long time. Anyway, setting this option could be emulated by just
+          directly hacking the code.
+        
+        This is an enormous speed-up in the LLInt build.
+
+        * _javascript_Core.xcodeproj/project.pbxproj: Prune the set of backends that we should consider on Xcode-based platforms.
+        * llint/LLIntOfflineAsmConfig.h: Remove ALWAYS_ALLOCATE_SLOW
+        * llint/LowLevelInterpreter.asm: Remove ALWAYS_ALLOCATE_SLOW
+        * offlineasm/backends.rb: Add infrastructure for reasoning about valid backends.
+        * offlineasm/generate_offset_extractor.rb: Allow the client to specify a filtered set of valid backends.
+        * offlineasm/settings.rb: Improve the construction of settings combinations so that it doesn't traverse the enourmous set of obviously invalid multi-backend combinations. Also glue into support for valid backends.
+
+2014-08-19  Filip Pizlo  <[email protected]>
+
         Fix indentation and style in LowLevelInterpreter.asm
         https://bugs.webkit.org/show_bug.cgi?id=136083

Modified: trunk/Source/_javascript_Core/_javascript_Core.xcodeproj/project.pbxproj (172776 => 172777)


--- trunk/Source/_javascript_Core/_javascript_Core.xcodeproj/project.pbxproj	2014-08-19 23:20:37 UTC (rev 172776)
+++ trunk/Source/_javascript_Core/_javascript_Core.xcodeproj/project.pbxproj	2014-08-19 23:25:37 UTC (rev 172777)
@@ -6788,7 +6788,7 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
-			shellScript = "set -e\n\nmkdir -p \"${BUILT_PRODUCTS_DIR}/LLIntOffsets/\"\n\n/usr/bin/env ruby \"${SRCROOT}/offlineasm/generate_offset_extractor.rb\" \"-I${BUILT_PRODUCTS_DIR}/DerivedSources/_javascript_Core\" \"${SRCROOT}/llint/LowLevelInterpreter.asm\" \"${BUILT_PRODUCTS_DIR}/LLIntOffsets/LLIntDesiredOffsets.h\"\n";
+			shellScript = "set -e\n\nmkdir -p \"${BUILT_PRODUCTS_DIR}/LLIntOffsets/\"\n\n/usr/bin/env ruby \"${SRCROOT}/offlineasm/generate_offset_extractor.rb\" \"-I${BUILT_PRODUCTS_DIR}/DerivedSources/_javascript_Core\" \"${SRCROOT}/llint/LowLevelInterpreter.asm\" \"${BUILT_PRODUCTS_DIR}/LLIntOffsets/LLIntDesiredOffsets.h\" \"X86,X86_64,ARMv7,ARMv7s,ARM64,C_LOOP\"\n";
 		};
 		0FCEFAD91806191800472CE4 /* Copy LLVM Library Into Framework */ = {
 			isa = PBXShellScriptBuildPhase;

Modified: trunk/Source/_javascript_Core/llint/LLIntOfflineAsmConfig.h (172776 => 172777)


--- trunk/Source/_javascript_Core/llint/LLIntOfflineAsmConfig.h	2014-08-19 23:20:37 UTC (rev 172776)
+++ trunk/Source/_javascript_Core/llint/LLIntOfflineAsmConfig.h	2014-08-19 23:25:37 UTC (rev 172777)
@@ -154,12 +154,6 @@
 #define OFFLINE_ASM_EXECUTION_TRACING 0
 #endif
 
-#if LLINT_ALWAYS_ALLOCATE_SLOW
-#define OFFLINE_ASM_ALWAYS_ALLOCATE_SLOW 1
-#else
-#define OFFLINE_ASM_ALWAYS_ALLOCATE_SLOW 0
-#endif
-
 #if ENABLE(GGC)
 #define OFFLINE_ASM_GGC 1
 #else

Modified: trunk/Source/_javascript_Core/llint/LowLevelInterpreter.asm (172776 => 172777)


--- trunk/Source/_javascript_Core/llint/LowLevelInterpreter.asm	2014-08-19 23:20:37 UTC (rev 172776)
+++ trunk/Source/_javascript_Core/llint/LowLevelInterpreter.asm	2014-08-19 23:25:37 UTC (rev 172777)
@@ -658,25 +658,21 @@
 end
 
 macro allocateJSObject(allocator, structure, result, scratch1, slowCase)
-    if ALWAYS_ALLOCATE_SLOW
-        jmp slowCase
-    else
-        const offsetOfFirstFreeCell = 
-            MarkedAllocator::m_freeList + 
-            MarkedBlock::FreeList::head
+    const offsetOfFirstFreeCell = 
+        MarkedAllocator::m_freeList + 
+        MarkedBlock::FreeList::head
 
-        # Get the object from the free list.   
-        loadp offsetOfFirstFreeCell[allocator], result
-        btpz result, slowCase
-        
-        # Remove the object from the free list.
-        loadp [result], scratch1
-        storep scratch1, offsetOfFirstFreeCell[allocator]
+    # Get the object from the free list.   
+    loadp offsetOfFirstFreeCell[allocator], result
+    btpz result, slowCase
     
-        # Initialize the object.
-        storep 0, JSObject::m_butterfly[result]
-        storeStructureWithTypeInfo(result, structure, scratch1)
-    end
+    # Remove the object from the free list.
+    loadp [result], scratch1
+    storep scratch1, offsetOfFirstFreeCell[allocator]
+
+    # Initialize the object.
+    storep 0, JSObject::m_butterfly[result]
+    storeStructureWithTypeInfo(result, structure, scratch1)
 end
 
 macro doReturn()

Modified: trunk/Source/_javascript_Core/offlineasm/backends.rb (172776 => 172777)


--- trunk/Source/_javascript_Core/offlineasm/backends.rb	2014-08-19 23:20:37 UTC (rev 172776)
+++ trunk/Source/_javascript_Core/offlineasm/backends.rb	2014-08-19 23:25:37 UTC (rev 172777)
@@ -67,6 +67,37 @@
 
 BACKEND_PATTERN = Regexp.new('\\A(' + BACKENDS.join(')|(') + ')\\Z')
 
+$allBackends = {}
+$validBackends = {}
+BACKENDS.each {
+    | backend |
+    $validBackends[backend] = true
+    $allBackends[backend] = true
+}
+
+def includeOnlyBackends(list)
+    newValidBackends = {}
+    list.each {
+        | backend |
+        if $validBackends[backend]
+            newValidBackends[backend] = true
+        end
+    }
+    $validBackends = newValidBackends
+end
+
+def isBackend?(backend)
+    $allBackends[backend]
+end
+
+def isValidBackend?(backend)
+    $validBackends[backend]
+end
+
+def validBackends
+    $validBackends.keys
+end
+
 class Node
     def lower(name)
         begin

Modified: trunk/Source/_javascript_Core/offlineasm/generate_offset_extractor.rb (172776 => 172777)


--- trunk/Source/_javascript_Core/offlineasm/generate_offset_extractor.rb	2014-08-19 23:20:37 UTC (rev 172776)
+++ trunk/Source/_javascript_Core/offlineasm/generate_offset_extractor.rb	2014-08-19 23:25:37 UTC (rev 172777)
@@ -39,6 +39,12 @@
 inputFlnm = ARGV.shift
 outputFlnm = ARGV.shift
 
+validBackends = ARGV.shift
+if validBackends
+    $stderr.puts "Only dealing with backends: #{validBackends}"
+    includeOnlyBackends(validBackends.split(","))
+end
+
 $stderr.puts "offlineasm: Parsing #{inputFlnm} and creating offset extractor #{outputFlnm}."
 
 def emitMagicNumber

Modified: trunk/Source/_javascript_Core/offlineasm/settings.rb (172776 => 172777)


--- trunk/Source/_javascript_Core/offlineasm/settings.rb	2014-08-19 23:20:37 UTC (rev 172776)
+++ trunk/Source/_javascript_Core/offlineasm/settings.rb	2014-08-19 23:25:37 UTC (rev 172777)
@@ -54,8 +54,29 @@
         settingsCombinator(settingsCombinations, newMap, remaining[1..-1])
     end
     
-    settingsCombinator(settingsCombinations, {}, (ast.filter(Setting).uniq.collect{|v| v.name} + BACKENDS).uniq)
+    nonBackendSettings = ast.filter(Setting).uniq.collect{ |v| v.name }
+    nonBackendSettings.delete_if {
+        | setting |
+        isBackend? setting
+    }
     
+    allBackendsFalse = {}
+    BACKENDS.each {
+        | backend |
+        allBackendsFalse[backend] = false
+    }
+    
+    # This will create entries for invalid backends. That's fine. It's necessary
+    # because it ensures that generate_offsets_extractor (which knows about valid
+    # backends) has settings indices that are compatible with what asm will see
+    # (asm doesn't know about valid backends).
+    BACKENDS.each {
+        | backend |
+        map = allBackendsFalse.clone
+        map[backend] = true
+        settingsCombinator(settingsCombinations, map, nonBackendSettings)
+    }
+    
     settingsCombinations
 end
 
@@ -73,15 +94,13 @@
     selectedBackend = nil
     BACKENDS.each {
         | backend |
-        isSupported = concreteSettings[backend]
-        raise unless isSupported != nil
-        numClaimedBackends += if isSupported then 1 else 0 end
-        if isSupported
+        if concreteSettings[backend]
+            raise if selectedBackend
             selectedBackend = backend
         end
     }
     
-    return if numClaimedBackends > 1
+    return unless isValidBackend? selectedBackend
     
     # Resolve the AST down to a low-level form (no macros or conditionals).
     lowLevelAST = ast.resolveSettings(concreteSettings)

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