Reviewers: Mads Ager,
Description:
Use bit fields to calculate compare stub minor key
Please review this at http://codereview.chromium.org/1081010
SVN Base: http://v8.googlecode.com/svn/branches/bleeding_edge/
Affected files:
M src/arm/codegen-arm.cc
M src/codegen.h
M src/ia32/codegen-ia32.cc
M src/x64/codegen-x64.cc
Index: src/ia32/codegen-ia32.cc
===================================================================
--- src/ia32/codegen-ia32.cc (revision 4200)
+++ src/ia32/codegen-ia32.cc (working copy)
@@ -11530,11 +11530,13 @@
int CompareStub::MinorKey() {
- // Encode the three parameters in a unique 16 bit value.
+ // Encode the three parameters in a unique 16 bit value. To avoid
duplicate
+ // stubs the never NaN NaN condition is only taken into account if the
+ // condition is equals.
ASSERT(static_cast<unsigned>(cc_) < (1 << 14));
- int nnn_value = (never_nan_nan_ ? 2 : 0);
- if (cc_ != equal) nnn_value = 0; // Avoid duplicate stubs.
- return (static_cast<unsigned>(cc_) << 2) | nnn_value | (strict_ ? 1 : 0);
+ return ConditionField::encode(static_cast<unsigned>(cc_))
+ | StrictField::encode(strict_)
+ | NeverNanNanField::encode(cc_ == equal ? never_nan_nan_ : false);
}
Index: src/codegen.h
===================================================================
--- src/codegen.h (revision 4200)
+++ src/codegen.h (working copy)
@@ -361,6 +361,11 @@
// stubs.
bool never_nan_nan_;
+ // Encoding of the minor key CCCCCCCCCCCCCCNS.
+ class StrictField: public BitField<bool, 0, 1> {};
+ class NeverNanNanField: public BitField<bool, 1, 1> {};
+ class ConditionField: public BitField<int, 2, 14> {};
+
Major MajorKey() { return Compare; }
int MinorKey();
Index: src/x64/codegen-x64.cc
===================================================================
--- src/x64/codegen-x64.cc (revision 4200)
+++ src/x64/codegen-x64.cc (working copy)
@@ -9105,11 +9105,13 @@
int CompareStub::MinorKey() {
- // Encode the three parameters in a unique 16 bit value.
+ // Encode the three parameters in a unique 16 bit value. To avoid
duplicate
+ // stubs the never NaN NaN condition is only taken into account if the
+ // condition is equals.
ASSERT(static_cast<unsigned>(cc_) < (1 << 14));
- int nnn_value = (never_nan_nan_ ? 2 : 0);
- if (cc_ != equal) nnn_value = 0; // Avoid duplicate stubs.
- return (static_cast<unsigned>(cc_) << 2) | nnn_value | (strict_ ? 1 : 0);
+ return ConditionField::encode(static_cast<unsigned>(cc_))
+ | StrictField::encode(strict_)
+ | NeverNanNanField::encode(cc_ == equal ? never_nan_nan_ : false);
}
Index: src/arm/codegen-arm.cc
===================================================================
--- src/arm/codegen-arm.cc (revision 4200)
+++ src/arm/codegen-arm.cc (working copy)
@@ -7159,11 +7159,14 @@
int CompareStub::MinorKey() {
- // Encode the three parameters in a unique 16 bit value.
- ASSERT((static_cast<unsigned>(cc_) >> 26) < (1 << 16));
- int nnn_value = (never_nan_nan_ ? 2 : 0);
- if (cc_ != eq) nnn_value = 0; // Avoid duplicate stubs.
- return (static_cast<unsigned>(cc_) >> 26) | nnn_value | (strict_ ? 1 :
0);
+ // Encode the three parameters in a unique 16 bit value. To avoid
duplicate
+ // stubs the never NaN NaN condition is only taken into account if the
+ // condition is equals.
+ ASSERT((static_cast<unsigned>(cc_) >> 28) < (1 << 14));
+ return ConditionField::encode(static_cast<unsigned>(cc_) >> 28)
+ | StrictField::encode(strict_)
+ | NeverNanNanField::encode(cc_ == eq ? never_nan_nan_ : false);
+
}
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