Revision: 4172
Author: [email protected]
Date: Wed Mar 17 09:39:29 2010
Log: Fix type propagation rules for count operation.
Also treat const-variables as not side-effect free.
Review URL: http://codereview.chromium.org/982009
http://code.google.com/p/v8/source/detail?r=4172
Modified:
/branches/bleeding_edge/src/ia32/codegen-ia32.cc
/branches/bleeding_edge/src/rewriter.cc
/branches/bleeding_edge/test/mjsunit/compiler/loopcount.js
=======================================
--- /branches/bleeding_edge/src/ia32/codegen-ia32.cc Wed Mar 17 05:27:32
2010
+++ /branches/bleeding_edge/src/ia32/codegen-ia32.cc Wed Mar 17 09:39:29
2010
@@ -3762,6 +3762,21 @@
Visit(node->next());
}
}
+
+ // The update expression resets the type of the loop variable. So we
+ // set it to smi before compiling the test expression.
+ if (node->is_fast_smi_loop()) {
+ // Set number type of the loop variable to smi.
+ Slot* slot = node->loop_variable()->slot();
+ ASSERT(slot->type() == Slot::LOCAL);
+ frame_->SetTypeForLocalAt(slot->index(), NumberInfo::Smi());
+ if (FLAG_debug_code) {
+ frame_->PushLocalAt(slot->index());
+ Result var = frame_->Pop();
+ var.ToRegister();
+ __ AbortIfNotSmi(var.reg(), "Loop variable not a smi.");
+ }
+ }
// Based on the condition analysis, compile the backward jump as
// necessary.
@@ -6867,7 +6882,12 @@
old_value = allocator_->Allocate();
ASSERT(old_value.is_valid());
__ mov(old_value.reg(), new_value.reg());
- }
+
+ // The old value that is return for postfix operations has the
+ // same type as the input value we got from the frame.
+ old_value.set_number_info(new_value.number_info());
+ }
+
// Ensure the new value is writable.
frame_->Spill(new_value.reg());
@@ -6931,6 +6951,8 @@
}
deferred->BindExit();
+ // The result of ++ or -- is always a number.
+ new_value.set_number_info(NumberInfo::Number());
// Postfix: store the old value in the allocated slot under the
// reference.
=======================================
--- /branches/bleeding_edge/src/rewriter.cc Tue Mar 16 09:07:19 2010
+++ /branches/bleeding_edge/src/rewriter.cc Wed Mar 17 09:39:29 2010
@@ -247,7 +247,9 @@
}
if (FLAG_safe_int32_compiler) {
- if (var->IsStackAllocated() && !var->is_arguments()) {
+ if (var->IsStackAllocated() &&
+ !var->is_arguments() &&
+ var->mode() != Variable::CONST) {
node->set_side_effect_free(true);
}
}
=======================================
--- /branches/bleeding_edge/test/mjsunit/compiler/loopcount.js Tue Mar 16
09:03:40 2010
+++ /branches/bleeding_edge/test/mjsunit/compiler/loopcount.js Wed Mar 17
09:39:29 2010
@@ -53,3 +53,6 @@
return i;
}
assertEquals(-0x40000001, f5());
+
+function f6() { var x = 0x3fffffff; x++; return x+1; }
+assertEquals(0x40000001, f6());
--
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