[JSC] Make B3 Return opcode work without arguments

Benjamin Poulain · webkit-commit-queue · commit 61c659391826 · 2016-08-12T01:33:48.000Z
https://bugs.webkit.org/show_bug.cgi?id=160787 Patch by Benjamin Poulain <bpoulain@apple.com> on 2016-08-11 Reviewed by Keith Miller. We need a way to create functions that do not return values. * assembler/MacroAssembler.h: (JSC::MacroAssembler::retVoid): * b3/B3BasicBlock.cpp: (JSC::B3::BasicBlock::appendNewControlValue): * b3/B3LowerToAir.cpp: (JSC::B3::Air::LowerToAir::lower): * b3/B3Validate.cpp: * b3/B3Value.h: * b3/air/AirOpcode.opcodes: * b3/testb3.cpp: (JSC::B3::testReturnVoid): (JSC::B3::run): Canonical link: https://commits.webkit.org/178912@main git-svn-id: https://svn.webkit.org/repository/webkit/trunk@204402 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/JavaScriptCore/ChangeLog b/Source/JavaScriptCore/ChangeLog
@@ -1,3 +1,25 @@
+2016-08-11  Benjamin Poulain  <bpoulain@apple.com>
+
+        [JSC] Make B3 Return opcode work without arguments
+        https://bugs.webkit.org/show_bug.cgi?id=160787
+
+        Reviewed by Keith Miller.
+
+        We need a way to create functions that do not return values.
+
+        * assembler/MacroAssembler.h:
+        (JSC::MacroAssembler::retVoid):
+        * b3/B3BasicBlock.cpp:
+        (JSC::B3::BasicBlock::appendNewControlValue):
+        * b3/B3LowerToAir.cpp:
+        (JSC::B3::Air::LowerToAir::lower):
+        * b3/B3Validate.cpp:
+        * b3/B3Value.h:
+        * b3/air/AirOpcode.opcodes:
+        * b3/testb3.cpp:
+        (JSC::B3::testReturnVoid):
+        (JSC::B3::run):
+
 2016-08-11  Mark Lam  <mark.lam@apple.com>
 
         Gardening: fix gcc builds after r204387. 
diff --git a/Source/JavaScriptCore/assembler/MacroAssembler.h b/Source/JavaScriptCore/assembler/MacroAssembler.h
@@ -492,6 +492,7 @@ class MacroAssembler : public MacroAssemblerBase {
 
     // B3 has additional pseudo-opcodes for returning, when it wants to signal that the return
     // consumes some register in some way.
+    void retVoid() { ret(); }
     void ret32(RegisterID) { ret(); }
     void ret64(RegisterID) { ret(); }
     void retFloat(FPRegisterID) { ret(); }
diff --git a/Source/JavaScriptCore/b3/B3BasicBlock.cpp b/Source/JavaScriptCore/b3/B3BasicBlock.cpp
@@ -166,7 +166,7 @@ void BasicBlock::deepDump(const Procedure& proc, PrintStream& out) const
 
 Value* BasicBlock::appendNewControlValue(Procedure& proc, Opcode opcode, Origin origin)
 {
-    RELEASE_ASSERT(opcode == Oops);
+    RELEASE_ASSERT(opcode == Oops || opcode == Return);
     clearSuccessors();
     return appendNew<Value>(proc, opcode, origin);
 }
diff --git a/Source/JavaScriptCore/b3/B3LowerToAir.cpp b/Source/JavaScriptCore/b3/B3LowerToAir.cpp
@@ -2431,6 +2431,10 @@ class LowerToAir {
         }
 
         case Return: {
+            if (!m_value->numChildren()) {
+                append(RetVoid);
+                return;
+            }
             Value* value = m_value->child(0);
             Tmp returnValueGPR = Tmp(GPRInfo::returnValueGPR);
             Tmp returnValueFPR = Tmp(FPRInfo::returnValueFPR);
diff --git a/Source/JavaScriptCore/b3/B3Validate.cpp b/Source/JavaScriptCore/b3/B3Validate.cpp
@@ -388,7 +388,7 @@ class Validater {
                 VALIDATE(!valueOwner.get(value)->numSuccessors(), ("At ", *value));
                 break;
             case Return:
-                VALIDATE(value->numChildren() == 1, ("At ", *value));
+                VALIDATE(value->numChildren() <= 1, ("At ", *value));
                 VALIDATE(value->type() == Void, ("At ", *value));
                 VALIDATE(!valueOwner.get(value)->numSuccessors(), ("At ", *value));
                 break;
diff --git a/Source/JavaScriptCore/b3/B3Value.h b/Source/JavaScriptCore/b3/B3Value.h
@@ -287,6 +287,10 @@ class JS_EXPORT_PRIVATE Value {
             if (UNLIKELY(numArgs))
                 badOpcode(opcode, numArgs);
             break;
+        case Return:
+            if (UNLIKELY(numArgs > 1))
+                badOpcode(opcode, numArgs);
+            break;
         case Identity:
         case Neg:
         case Clz:
@@ -305,7 +309,6 @@ class JS_EXPORT_PRIVATE Value {
         case IToF:
         case BitwiseCast:
         case Branch:
-        case Return:
             if (UNLIKELY(numArgs != 1))
                 badOpcode(opcode, numArgs);
             break;
diff --git a/Source/JavaScriptCore/b3/air/AirOpcode.opcodes b/Source/JavaScriptCore/b3/air/AirOpcode.opcodes
@@ -836,6 +836,8 @@ MoveDoubleConditionallyFloat U:G:32, U:F:32, U:F:32, U:F:64, U:F:64, D:F:64
 
 Jump /branch
 
+RetVoid /return
+
 Ret32 U:G:32 /return
     Tmp
 
diff --git a/Source/JavaScriptCore/b3/testb3.cpp b/Source/JavaScriptCore/b3/testb3.cpp
@@ -351,6 +351,14 @@ void testReturnConst64(int64_t value)
     CHECK(compileAndRun<int64_t>(proc) == value);
 }
 
+void testReturnVoid()
+{
+    Procedure proc;
+    BasicBlock* root = proc.addBlock();
+    root->appendNewControlValue(proc, Return, Origin());
+    compileAndRun<void>(proc);
+}
+
 void testAddArg(int a)
 {
     Procedure proc;
@@ -12944,6 +12952,7 @@ void run(const char* filter)
     RUN(testArg(43));
     RUN(testReturnConst64(5));
     RUN(testReturnConst64(-42));
+    RUN(testReturnVoid());
 
     RUN(testAddArg(111));
     RUN(testAddArgs(1, 1));

Original file line number	Diff line number	Diff line change
`@@ -166,7 +166,7 @@ void BasicBlock::deepDump(const Procedure& proc, PrintStream& out) const`
`166`	`166`
`167`	`167`	`Value* BasicBlock::appendNewControlValue(Procedure& proc, Opcode opcode, Origin origin)`
`168`	`168`	`{`
`169`		`- RELEASE_ASSERT(opcode == Oops);`
	`169`	`+ RELEASE_ASSERT(opcode == Oops \|\| opcode == Return);`
`170`	`170`	`clearSuccessors();`
`171`	`171`	`return appendNew<Value>(proc, opcode, origin);`
`172`	`172`	`}`