Changeset 189599 in webkit

Timestamp:

Sep 10, 2015 6:37:09 PM (9 years ago)

Author:

commit-queue@webkit.org

Message:

Implement switch statements in WebAssembly
​https://bugs.webkit.org/show_bug.cgi?id=149051

Patch by Sukolsak Sakshuwong <Sukolsak Sakshuwong> on 2015-09-10
Reviewed by Geoffrey Garen.

This patch implements switch statements in WebAssembly using the
JSC::BinarySwitch class.

• tests/stress/wasm-control-flow.js:
• tests/stress/wasm/control-flow.wasm:
• wasm/WASMFunctionCompiler.h:

(JSC::WASMFunctionCompiler::buildSwitch):

• wasm/WASMFunctionParser.cpp:

(JSC::WASMFunctionParser::parseSwitchStatement):

• wasm/WASMFunctionSyntaxChecker.h:

(JSC::WASMFunctionSyntaxChecker::buildSwitch):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• tests/stress/wasm-control-flow.js (modified) (4 diffs)
• tests/stress/wasm/control-flow.wasm (modified) (previous)
• wasm/WASMFunctionCompiler.h (modified) (2 diffs)
• wasm/WASMFunctionParser.cpp (modified) (4 diffs)
• wasm/WASMFunctionSyntaxChecker.h (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2015-09-10  Sukolsak Sakshuwong  <sukolsak@gmail.com>
+
+        Implement switch statements in WebAssembly
+        https://bugs.webkit.org/show_bug.cgi?id=149051
+
+        Reviewed by Geoffrey Garen.
+
+        This patch implements switch statements in WebAssembly using the
+        JSC::BinarySwitch class.
+
+        * tests/stress/wasm-control-flow.js:
+        * tests/stress/wasm/control-flow.wasm:
+        * wasm/WASMFunctionCompiler.h:
+        (JSC::WASMFunctionCompiler::buildSwitch):
+        * wasm/WASMFunctionParser.cpp:
+        (JSC::WASMFunctionParser::parseSwitchStatement):
+        * wasm/WASMFunctionSyntaxChecker.h:
+        (JSC::WASMFunctionSyntaxChecker::buildSwitch):
+
 2015-09-10  Filip Pizlo  <fpizlo@apple.com>
 

trunk/Source/JavaScriptCore/tests/stress/wasm-control-flow.js

@@ -203 +203 @@
         }
         return x;
+    }
+
+    function switchCase(x) {
+        x = x | 0;
+        var y = 0;
+        switch (x) {
+        case 0:
+            y = 1;
+            break;
+        case 1:
+            y = 2;
+            break;
+        case 2:
+            y = 3;
+            break;
+        }
+        return y;
+    }
+
+    function switchFallThrough(x) {
+        x = x | 0;
+        var y = 0;
+        switch (x) {
+        case 3:
+            y = (y + 1000) | 0;
+        case 2:
+            y = (y + 100) | 0;
+        case 1:
+            y = (y + 10) | 0;
+        default:
+            y = (y + 1) | 0;
+        }
+        return y;
     }
 
@@ -223 +256 @@
         labelInLabelBreakOuter: labelInLabelBreakOuter,
         whileInWhileBreakOuter: whileInWhileBreakOuter,
+        switchCase: switchCase,
+        switchFallThrough: switchFallThrough,
     };
 }
@@ -234 +269 @@
 shouldBe(module.ifElseFalse(), 2);
 shouldBe(module.ifInIf(), 3);
+
 shouldBe(module.whileLoop(), 5);
 shouldBe(module.whileBreak(), 2);
 shouldBe(module.whileContinue(), 4);
 shouldBe(module.whileInWhile(), 10);
+
 shouldBe(module.doLoop(), 1);
 shouldBe(module.doBreak(), 2);
 shouldBe(module.doContinue(), 4);
+
 shouldBe(module.labelBreak(), 1);
 shouldBe(module.labelContinue(), 1);
@@ -246 +284 @@
 shouldBe(module.labelInLabelBreakOuter(), 2);
 shouldBe(module.whileInWhileBreakOuter(), 8);
+
+shouldBe(module.switchCase(0), 1);
+shouldBe(module.switchCase(1), 2);
+shouldBe(module.switchCase(2), 3);
+shouldBe(module.switchCase(3), 0);
+shouldBe(module.switchFallThrough(0), 1);
+shouldBe(module.switchFallThrough(1), 11);
+shouldBe(module.switchFallThrough(2), 111);
+shouldBe(module.switchFallThrough(3), 1111);
+shouldBe(module.switchFallThrough(4), 1);

trunk/Source/JavaScriptCore/wasm/WASMFunctionCompiler.h

@@ -29 +29 @@
 #if ENABLE(WEBASSEMBLY)
 
+#include "BinarySwitch.h"
 #include "CCallHelpers.h"
 #include "JIT.h"
@@ -635 +636 @@
     }
 
+    void buildSwitch(int, const Vector<int64_t>& cases, Vector<JumpTarget>& targets, JumpTarget defaultTarget)
+    {
+        load32(temporaryAddress(m_tempStackTop - 1), GPRInfo::regT0);
+        m_tempStackTop--;
+        BinarySwitch binarySwitch(GPRInfo::regT0, cases, BinarySwitch::Int32);
+        while (binarySwitch.advance(*this)) {
+            unsigned index = binarySwitch.caseIndex();
+            jump(targets[index].label);
+        }
+        binarySwitch.fallThrough().linkTo(defaultTarget.label, this);
+    }
+
 private:
     union StackSlot {

trunk/Source/JavaScriptCore/wasm/WASMFunctionParser.cpp

@@ -416 +416 @@
 ContextStatement WASMFunctionParser::parseSwitchStatement(Context& context)
 {
+    context.startSwitch();
     uint32_t numberOfCases;
     READ_COMPACT_UINT32_OR_FAIL(numberOfCases, "Cannot read the number of cases.");
-    parseExpressionI32(context);
-    PROPAGATE_ERROR();
+    ContextExpression expression = parseExpressionI32(context);
+    PROPAGATE_ERROR();
+
+    ContextJumpTarget compare;
+    context.jumpToTarget(compare);
+
+    Vector<int64_t> cases;
+    Vector<ContextJumpTarget> targets;
+    cases.reserveInitialCapacity(numberOfCases);
+    targets.reserveInitialCapacity(numberOfCases);
+    bool hasDefault = false;
+    ContextJumpTarget defaultTarget;
 
     m_breakScopeDepth++;
@@ -431 +442 @@
             uint32_t value;
             READ_COMPACT_INT32_OR_FAIL(value, "Cannot read the value of the switch case.");
+            cases.uncheckedAppend(value);
+            ContextJumpTarget target;
+            context.linkTarget(target);
+            targets.uncheckedAppend(target);
             if (switchCase == WASMSwitchCase::CaseWithStatement) {
                 parseStatement(context);
@@ -444 +459 @@
         case WASMSwitchCase::DefaultWithBlockStatement: {
             FAIL_IF_FALSE(i == numberOfCases - 1, "The default case must be the last case.");
+            hasDefault = true;
+            context.linkTarget(defaultTarget);
             if (switchCase == WASMSwitchCase::DefaultWithStatement) {
                 parseStatement(context);
@@ -457 +474 @@
         }
     }
+    if (!hasDefault)
+        context.linkTarget(defaultTarget);
+
     m_breakScopeDepth--;
-    // FIXME: Implement this instruction.
+
+    context.jumpToTarget(context.breakTarget());
+    context.linkTarget(compare);
+
+    context.buildSwitch(expression, cases, targets, defaultTarget);
+
+    context.linkTarget(context.breakTarget());
+    context.endSwitch();
     return UNUSED;
 }

trunk/Source/JavaScriptCore/wasm/WASMFunctionSyntaxChecker.h

@@ -156 +156 @@
     int continueLabelTarget(uint32_t) { return UNUSED; }
 
+    void buildSwitch(int, const Vector<int64_t>&, const Vector<int>&, const int&)
+    {
+        m_tempStackTop--;
+    }
+
     unsigned stackHeight()
     {