Revision: 21539
Author: plin...@gmail.com
Date: Tue May 27 17:11:33 2014 UTC
Log: MIPS: Convert String array index/length hash to BitField.
Port r21533 (736c779)
BUG=
R=plin...@gmail.com
Review URL: https://codereview.chromium.org/297233007
Patch from Balazs Kilvady <kilva...@homejinni.com>.
http://code.google.com/p/v8/source/detail?r=21539
Modified:
/branches/bleeding_edge/src/mips/macro-assembler-mips.cc
/branches/bleeding_edge/src/mips/macro-assembler-mips.h
=======================================
--- /branches/bleeding_edge/src/mips/macro-assembler-mips.cc Tue May 27
13:37:33 2014 UTC
+++ /branches/bleeding_edge/src/mips/macro-assembler-mips.cc Tue May 27
17:11:33 2014 UTC
@@ -3999,19 +3999,14 @@
}
-void MacroAssembler::IndexFromHash(Register hash,
- Register index) {
+void MacroAssembler::IndexFromHash(Register hash, Register index) {
// If the hash field contains an array index pick it out. The assert
checks
// that the constants for the maximum number of digits for an array index
// cached in the hash field and the number of bits reserved for it does
not
// conflict.
ASSERT(TenToThe(String::kMaxCachedArrayIndexLength) <
(1 << String::kArrayIndexValueBits));
- // We want the smi-tagged index in key. kArrayIndexValueMask has zeros
in
- // the low kHashShift bits.
- STATIC_ASSERT(kSmiTag == 0);
- Ext(hash, hash, String::kHashShift, String::kArrayIndexValueBits);
- sll(index, hash, kSmiTagSize);
+ DecodeFieldToSmi<String::ArrayIndexValueBits>(index, hash);
}
=======================================
--- /branches/bleeding_edge/src/mips/macro-assembler-mips.h Mon May 26
11:28:08 2014 UTC
+++ /branches/bleeding_edge/src/mips/macro-assembler-mips.h Tue May 27
17:11:33 2014 UTC
@@ -1485,17 +1485,33 @@
template<typename Field>
void DecodeField(Register dst, Register src) {
+ Ext(dst, src, Field::kShift, Field::kSize);
+ }
+
+ template<typename Field>
+ void DecodeField(Register reg) {
+ DecodeField<Field>(reg, reg);
+ }
+
+ template<typename Field>
+ void DecodeFieldToSmi(Register dst, Register src) {
static const int shift = Field::kShift;
- static const int mask = Field::kMask >> shift;
- static const int size = Field::kSize;
- srl(dst, src, shift);
- if (shift + size != 32) {
+ static const int mask = Field::kMask >> shift << kSmiTagSize;
+ STATIC_ASSERT((mask & (0x80000000u >> (kSmiTagSize - 1))) == 0);
+ STATIC_ASSERT(kSmiTag == 0);
+ if (shift < kSmiTagSize) {
+ sll(dst, src, kSmiTagSize - shift);
And(dst, dst, Operand(mask));
+ } else if (shift > kSmiTagSize) {
+ srl(dst, src, shift - kSmiTagSize);
+ And(dst, dst, Operand(mask));
+ } else {
+ And(dst, src, Operand(mask));
}
}
template<typename Field>
- void DecodeField(Register reg) {
+ void DecodeFieldToSmi(Register reg) {
DecodeField<Field>(reg, reg);
}
--
--
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