V4: Replace a QSet with a QVector in calculateOptionalJumps

Instead of storing a bunch of statement IDs in a QSet, the parent basic
block of the terminator statement (specifically: the jump) is used as
an index into a bit vector. If the bit is set, this indicates that the
jump can be omitted.

This reduces the number of allocations from 1 hash node per optional
jump, to 1 per function. The allocation will also be smaller then a
hash node.

Change-Id: Ia34468534b96dd9cefa837523bf89ad233de92e8
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 2 insertions, 1 deletions

diff --git a/src/qml/jit/qv4isel_masm_p.h b/src/qml/jit/qv4isel_masm_p.h
index 5bca879a77..0e909820e7 100644
--- a/src/qml/jit/qv4isel_masm_p.h
+++ b/src/qml/jit/qv4isel_masm_p.h
@@ -54,6 +54,7 @@
 #include "private/qv4jsir_p.h"
 #include "private/qv4isel_p.h"
 #include "private/qv4isel_util_p.h"
+#include "private/qv4util_p.h"
 #include "private/qv4value_p.h"
 #include "private/qv4lookup_p.h"
 
@@ -272,7 +273,7 @@ private:
     }
 
     IR::BasicBlock *_block;
-    QSet<IR::Jump *> _removableJumps;
+    BitVector _removableJumps;
     Assembler* _as;
 
     QScopedPointer<CompilationUnit> compilationUnit;