Author: whessev8
Date: Fri Jan 23 05:58:49 2009
New Revision: 1137
Modified:
branches/bleeding_edge/src/codegen-ia32.cc
Log:
Optimizes an assembly-language conversion from int to Smi in codegen.
Review URL: http://codereview.chromium.org/18551
Modified: branches/bleeding_edge/src/codegen-ia32.cc
==============================================================================
--- branches/bleeding_edge/src/codegen-ia32.cc (original)
+++ branches/bleeding_edge/src/codegen-ia32.cc Fri Jan 23 05:58:49 2009
@@ -1127,14 +1127,14 @@
__ j(not_zero, deferred->enter(), not_taken);
__ sar(ebx, kSmiTagSize);
__ shl(ebx, shift_value);
- // This is the Smi check for the shifted result.
- // After signed subtraction of 0xc0000000, the valid
- // Smis are positive.
- __ cmp(ebx, 0xc0000000);
- __ j(sign, deferred->enter(), not_taken);
- // tag result and store it in TOS (eax)
- ASSERT(kSmiTagSize == times_2); // adjust code if not the case
- __ lea(eax, Operand(ebx, ebx, times_1, kSmiTag));
+ // Convert the int to a Smi, and check that it is in
+ // the range of valid Smis.
+ ASSERT(kSmiTagSize == times_2); // Adjust code if not true.
+ ASSERT(kSmiTag == 0); // Adjust code if not true.
+ __ add(ebx, Operand(ebx));
+ __ j(overflow, deferred->enter(), not_taken);
+ __ mov(eax, Operand(ebx));
+
__ bind(deferred->exit());
frame_->Push(eax);
}
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