Fix MathFloorOfDiv optimization on non-SDIV ARM

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index f69fbc9b938cc5466d859771eb707ee1b1762c54..8a6ccbc9e2cbe364fb7e973372e478437c45a73d 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -1550,6 +1550,9 @@ HValue* HUnaryMathOperation::Canonicalize() {
       HValue* new_right =
           LChunkBuilder::SimplifiedDivisorForMathFloorOfDiv(right);
       if (new_right == NULL &&
+#ifdef V8_TARGET_ARCH_ARM

[Sven Panne, 2013/06/14 20:05:25]

o_O I think we're doing something fundamentally wrong here if we use
target-specific #ifdefs. It's OK for a temporary quick-n-dirty (performance?
can't even tell...) fix to get things landed, but this should be removed as
quickly as possible at all cost (no idea how, let's talk next week).

We already have the ugly #ifdef wart because of the non-uniform handling of the
context register here, we should improve things and not make it worse.

+          CpuFeatures::IsSupported(SUDIV) &&
+#endif
           hdiv->observed_input_representation(2).IsSmiOrInteger32()) {
         new_right = new(block()->zone())
             HChange(right, Representation::Integer32(), false, false);