Changeset 220047 in webkit for trunk/Source/JavaScriptCore/offlineasm/asm.rb

Timestamp:

Jul 29, 2017, 8:01:12 PM (8 years ago)

Author:

[email protected]

Message:

LLInt offsets extractor should be able to handle C++ constexprs
​https://bugs.webkit.org/show_bug.cgi?id=174964

Reviewed by Saam Barati.

This patch adds new syntax to the offline asm language. The new keyword,
constexpr, takes the subsequent identifier and maps it to a C++ constexpr
expression. Additionally, if the value is not an identifier you can wrap it in
parentheses. e.g. constexpr (myConstexprFunction() + OBJECT_OFFSET(Foo, bar)),
which will get converted into:
static_cast<int64_t>(myConstexprFunction() + OBJECT_OFFSET(Foo, bar));

This patch also changes the data format the LLIntOffsetsExtractor
binary produces. Previously, it would produce unsigned values,
after this patch every value is an int64_t. Using an int64_t is
useful because it means that we can represent any constant needed.
int32_t masks are sign extended then passed then converted to a
negative literal sting in the assembler so it will be the constant
expected.

• llint/LLIntOffsetsExtractor.cpp:

(JSC::LLIntOffsetsExtractor::dummy):

• llint/LowLevelInterpreter.asm:
• llint/LowLevelInterpreter64.asm:
• offlineasm/asm.rb:
• offlineasm/ast.rb:
• offlineasm/generate_offset_extractor.rb:
• offlineasm/offsets.rb:
• offlineasm/parser.rb:
• offlineasm/transform.rb:

File:

• trunk/Source/JavaScriptCore/offlineasm/asm.rb (modified) (2 diffs)

trunk/Source/JavaScriptCore/offlineasm/asm.rb

@@ -316 +316 @@
 rescue MissingMagicValuesException
     $stderr.puts "offlineasm: No magic values found. Skipping assembly file generation."
-    exit 0
+    exit 1
 end
 
@@ -367 +367 @@
             end
 
-            lowLevelAST = lowLevelAST.resolve(*buildOffsetsMap(lowLevelAST, offsetsList))
+            lowLevelAST = lowLevelAST.resolve(buildOffsetsMap(lowLevelAST, offsetsList))
             lowLevelAST.validate
             emitCodeInConfiguration(concreteSettings, lowLevelAST, backend) {