Revision: 4132
Author: [email protected]
Date: Mon Mar 15 07:24:37 2010
Log: Added fast case for shift operations when the left parameter is a
double and we know that the right parameter is a smi.
Review URL: http://codereview.chromium.org/955001
http://code.google.com/p/v8/source/detail?r=4132
Modified:
/branches/bleeding_edge/src/ia32/codegen-ia32.cc
=======================================
--- /branches/bleeding_edge/src/ia32/codegen-ia32.cc Mon Mar 15 07:03:36
2010
+++ /branches/bleeding_edge/src/ia32/codegen-ia32.cc Mon Mar 15 07:24:37
2010
@@ -1478,12 +1478,41 @@
left->number_info(),
right->number_info(),
overwrite_mode);
- CheckTwoForSminess(masm_, left->reg(), right->reg(), answer.reg(),
- left->number_info(), right->number_info(),
deferred);
-
- // Untag both operands.
- __ mov(answer.reg(), left->reg());
- __ SmiUntag(answer.reg());
+
+ Label do_op, left_nonsmi;
+ // if right is a smi we make a fast case if left is either a smi
+ // or a heapnumber.
+ if (CpuFeatures::IsSupported(SSE2) && right->number_info().IsSmi()) {
+ __ mov(answer.reg(), left->reg());
+ // Fast case - both are actually smis.
+ if (!left->number_info().IsSmi()) {
+ __ test(answer.reg(), Immediate(kSmiTagMask));
+ __ j(not_zero, &left_nonsmi);
+ }
+ __ SmiUntag(answer.reg());
+ __ jmp(&do_op);
+
+ __ bind(&left_nonsmi);
+ // Branch if not a heapnumber.
+ __ cmp(FieldOperand(answer.reg(), HeapObject::kMapOffset),
+ Factory::heap_number_map());
+ deferred->Branch(not_equal);
+
+ // Load integer value into answer register using truncation.
+ __ cvttsd2si(answer.reg(),
+ FieldOperand(answer.reg(), HeapNumber::kValueOffset));
+ // Branch if we do not fit in a smi.
+ __ cmp(answer.reg(), 0xc0000000);
+ deferred->Branch(negative);
+ } else {
+ CheckTwoForSminess(masm_, left->reg(), right->reg(), answer.reg(),
+ left->number_info(), right->number_info(),
deferred);
+
+ // Untag both operands.
+ __ mov(answer.reg(), left->reg());
+ __ SmiUntag(answer.reg());
+ }
+
__ SmiUntag(ecx);
// Perform the operation.
switch (op) {
--
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