Revision: 8916
Author: [email protected]
Date: Fri Aug 12 01:45:17 2011
Log: Do not use deprecated ARM instructions in
DirectCEntryStub::GenerateCall.
Non-ancient versions of the ARM-ARM explicitly deprecate most uses of the PC
within instructions and older ARM implementations have a non-predictable
offset
(8 or 12) for some of these deprecated uses. Avoiding the deprecated
instruction
costs us one additional instruction in DirectCEntryStub::GenerateCall, but
this
should not cause any significant performance degradation.
The deoptimizer still uses the PC in a stm instruction, but it is a bit
unclear
what to do about that, so simply a comment has been added to reconsider
this in
the future.
Review URL: http://codereview.chromium.org/7633014
http://code.google.com/p/v8/source/detail?r=8916
Modified:
/branches/bleeding_edge/src/arm/code-stubs-arm.cc
/branches/bleeding_edge/src/arm/deoptimizer-arm.cc
=======================================
--- /branches/bleeding_edge/src/arm/code-stubs-arm.cc Thu Aug 11 00:22:16
2011
+++ /branches/bleeding_edge/src/arm/code-stubs-arm.cc Fri Aug 12 01:45:17
2011
@@ -6319,7 +6319,9 @@
RelocInfo::CODE_TARGET));
__ mov(r2, Operand(function));
// Push return address (accessible to GC through exit frame pc).
- __ str(pc, MemOperand(sp, 0));
+ // Note that using pc with str is deprecated.
+ __ add(ip, pc, Operand(4));
+ __ str(ip, MemOperand(sp, 0));
__ Jump(r2); // Call the api function.
}
@@ -6329,7 +6331,9 @@
__ mov(lr, Operand(reinterpret_cast<intptr_t>(GetCode().location()),
RelocInfo::CODE_TARGET));
// Push return address (accessible to GC through exit frame pc).
- __ str(pc, MemOperand(sp, 0));
+ // Note that using pc with str is deprecated.
+ __ add(ip, pc, Operand(4));
+ __ str(ip, MemOperand(sp, 0));
__ Jump(target); // Call the C++ function.
}
=======================================
--- /branches/bleeding_edge/src/arm/deoptimizer-arm.cc Wed Aug 10 01:03:22
2011
+++ /branches/bleeding_edge/src/arm/deoptimizer-arm.cc Fri Aug 12 01:45:17
2011
@@ -593,6 +593,8 @@
__ vstm(db_w, sp, first, last);
// Push all 16 registers (needed to populate
FrameDescription::registers_).
+ // TODO(1588) Note that using pc with stm is deprecated, so we should
perhaps
+ // handle this a bit differently.
__ stm(db_w, sp, restored_regs | sp.bit() | lr.bit() | pc.bit());
const int kSavedRegistersAreaSize =
--
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