Revision: 20141
Author: svenpa...@chromium.org
Date: Fri Mar 21 07:08:08 2014 UTC
Log: Use constant length for memcpy on A64 simulator.
Compiler can't optimize away variable length memcpy.
About a 18% boost.
Before - 5:40
Richards: 75.2
DeltaBlue: 105
Crypto: 64.0
RayTrace: 188
EarleyBoyer: 146
RegExp: 23.8
Splay: 96.2
NavierStokes: 91.9
----
Score (version 7): 85.7
After - 4:39
Richards: 90.8
DeltaBlue: 134
Crypto: 81.7
RayTrace: 227
EarleyBoyer: 177
RegExp: 29.7
Splay: 126
NavierStokes: 108
----
Score (version 7): 106
R=rodolph.perfe...@gmail.com, svenpa...@chromium.org
Review URL: https://codereview.chromium.org/203263017
http://code.google.com/p/v8/source/detail?r=20141
Modified:
/branches/bleeding_edge/src/a64/simulator-a64.h
=======================================
--- /branches/bleeding_edge/src/a64/simulator-a64.h Thu Mar 20 15:25:27
2014 UTC
+++ /branches/bleeding_edge/src/a64/simulator-a64.h Fri Mar 21 07:08:08
2014 UTC
@@ -166,10 +166,18 @@
void Set(T new_value, unsigned size = sizeof(T)) {
ASSERT(size <= kSizeInBytes);
ASSERT(size <= sizeof(new_value));
+ STATIC_ASSERT(kXRegSize == kDRegSize);
+ STATIC_ASSERT(kWRegSize == kSRegSize);
// All AArch64 registers are zero-extending; Writing a W register
clears the
// top bits of the corresponding X register.
- memset(value_, 0, kSizeInBytes);
- memcpy(value_, &new_value, size);
+ if (size == kXRegSize) {
+ memcpy(value_, &new_value, kXRegSize);
+ } else if (size == kWRegSize) {
+ memset(value_, 0, kSizeInBytes);
+ memcpy(value_, &new_value, kWRegSize);
+ } else {
+ UNREACHABLE();
+ }
}
// Copy 'size' bytes of the register to the result, and zero-extend to
fill
@@ -178,8 +186,14 @@
T Get(unsigned size = sizeof(T)) const {
ASSERT(size <= kSizeInBytes);
T result;
- memset(&result, 0, sizeof(result));
- memcpy(&result, value_, size);
+ if (size == kXRegSize) {
+ memcpy(&result, value_, kXRegSize);
+ } else if (size == kWRegSize) {
+ memset(&result, 0, sizeof(result));
+ memcpy(&result, value_, kWRegSize);
+ } else {
+ UNREACHABLE();
+ }
return result;
}
--
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