emit only necessary return proxying code when outlining

3 files changed, 15 insertions, 24 deletions

diff --git a/tools/js-optimizer.js b/tools/js-optimizer.js
index 14d26a89..5c80abb6 100644
--- a/tools/js-optimizer.js
+++ b/tools/js-optimizer.js
@@ -3031,7 +3031,7 @@ function outline(ast) {
 
     var writes = {};
     var appearances = {};
-    var hasReturn = false, hasBreak = false, hasContinue = false;
+    var hasReturn = false, hasReturnInt = false, hasReturnDouble = false, hasBreak = false, hasContinue = false;
     var breaks = {};    // set of labels we break or continue
     var continues = {}; // to (name -> id, just like labels)
     var breakCapturers = 0;
@@ -3050,7 +3050,13 @@ function outline(ast) {
           appearances[name] = (appearances[name] || 0) + 1;
         }
       } else if (type == 'return') {
-        hasReturn = true;
+        if (!node[1]) {
+          hasReturn = true;
+        } else if (detectAsmCoercion(node[1]) == ASM_INT) {
+          hasReturnInt = true;
+        } else {
+          hasReturnDouble = true;
+        }
       } else if (type == 'break') {
         var label = node[1] || 0;
         if (!label && breakCapturers > 0) return; // no label, and captured
@@ -3079,13 +3085,14 @@ function outline(ast) {
         continueCapturers--;
       }
     });
+    assert(hasReturn + hasReturnInt + hasReturnDouble <= 1);
 
     var reads = {};
 
     for (var name in appearances) {
       if (appearances[name] > 0) reads[name] = 0;
     }
-    return { writes: writes, reads: reads, hasReturn: hasReturn, hasBreak: hasBreak, hasContinue: hasContinue, breaks: breaks, continues: continues, labels: labels };
+    return { writes: writes, reads: reads, hasReturn: hasReturn, hasReturnInt: hasReturnInt, hasReturnDouble: hasReturnDouble, hasBreak: hasBreak, hasContinue: hasContinue, breaks: breaks, continues: continues, labels: labels };
   }
 
   function makeAssign(dst, src) {
@@ -3128,7 +3135,7 @@ function outline(ast) {
       reps.push(['stat', ['assign', true, ['name', v], makeAsmCoercion(['sub', ['name', getAsmType(v, asmData) == ASM_INT ? 'HEAP32' : 'HEAPF32'], ['binary', '>>', ['binary', '+', ['name', 'sp'], ['num', asmData.stackPos[v]]], ['num', '2']]], getAsmType(v, asmData))]]);
     }
     // Generate new function
-    if (codeInfo.hasReturn || codeInfo.hasBreak || codeInfo.hasContinue) {
+    if (codeInfo.hasReturn || codeInfo.hasReturnInt || codeInfo.hasReturnDouble || codeInfo.hasBreak || codeInfo.hasContinue) {
       // we need to capture all control flow using a top-level labeled one-time loop in the outlined function
       var breakCapturers = 0;
       var continueCapturers = 0;
@@ -3199,10 +3206,14 @@ function outline(ast) {
           makeComparison(makeAsmCoercion(makeStackAccess(ASM_INT, asmData.controlStackPos), ASM_INT), '==', ['num', CONTROL_RETURN_VOID]),
           [['stat', ['return']]]
         ));
+      }
+      if (codeInfo.hasReturnInt) {
         reps.push(makeIf(
           makeComparison(makeAsmCoercion(makeStackAccess(ASM_INT, asmData.controlStackPos), ASM_INT), '==', ['num', CONTROL_RETURN_INT]),
           [['stat', ['return', makeStackAccess(ASM_INT, asmData.controlDataStackPos)]]]
         ));
+      }
+      if (codeInfo.hasReturnDouble) {
         reps.push(makeIf(
           makeComparison(makeAsmCoercion(makeStackAccess(ASM_INT, asmData.controlStackPos), ASM_INT), '==', ['num', CONTROL_RETURN_DOUBLE]),
           [['stat', ['return', makeStackAccess(ASM_DOUBLE, asmData.controlDataStackPos)]]]
diff --git a/tools/test-js-optimizer-asm-outline1-output.js b/tools/test-js-optimizer-asm-outline1-output.js
index 03d90cb7..78bfcb88 100644
--- a/tools/test-js-optimizer-asm-outline1-output.js
+++ b/tools/test-js-optimizer-asm-outline1-output.js
@@ -36,18 +36,10 @@ function lin3() {
   c(5);
   lin3$1(sp);
   lin3$0(sp);
-  if ((HEAP32[sp + 0 >> 2] | 0) == 5) {
-   STACKTOP = sp;
-   return;
-  }
   if ((HEAP32[sp + 0 >> 2] | 0) == 6) {
    STACKTOP = sp;
    return HEAP32[sp + 8 >> 2];
   }
-  if ((HEAP32[sp + 0 >> 2] | 0) == 7) {
-   STACKTOP = sp;
-   return HEAPF32[sp + 8 >> 2];
-  }
  }
  STACKTOP = sp;
  return 20;
diff --git a/tools/test-js-optimizer-asm-outline2-output.js b/tools/test-js-optimizer-asm-outline2-output.js
index d9c292a0..c70b0030 100644
--- a/tools/test-js-optimizer-asm-outline2-output.js
+++ b/tools/test-js-optimizer-asm-outline2-output.js
@@ -95,12 +95,6 @@ function _free($mem) {
    if ((HEAP32[sp + 632 >> 2] | 0) == 5) {
     return;
    }
-   if ((HEAP32[sp + 632 >> 2] | 0) == 6) {
-    return HEAP32[sp + 640 >> 2];
-   }
-   if ((HEAP32[sp + 632 >> 2] | 0) == 7) {
-    return HEAPF32[sp + 640 >> 2];
-   }
    if ((HEAP32[sp + 632 >> 2] | 0) == 1) {
     break;
    }
@@ -195,12 +189,6 @@ function _free($mem) {
    if ((HEAP32[sp + 632 >> 2] | 0) == 5) {
     return;
    }
-   if ((HEAP32[sp + 632 >> 2] | 0) == 6) {
-    return HEAP32[sp + 640 >> 2];
-   }
-   if ((HEAP32[sp + 632 >> 2] | 0) == 7) {
-    return HEAPF32[sp + 640 >> 2];
-   }
    if ((HEAP32[sp + 632 >> 2] | 0) == 1) {
     break;
    }