Reviewers: danno,
Description:
X87: Convert String array index/length hash to BitField.
Port r21533 (736c779)
BUG=
Please review this at https://codereview.chromium.org/298293007/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files (+18, -8 lines):
M src/x87/macro-assembler-x87.h
M src/x87/macro-assembler-x87.cc
Index: src/x87/macro-assembler-x87.cc
diff --git a/src/x87/macro-assembler-x87.cc b/src/x87/macro-assembler-x87.cc
index
7baa659d014d79864d3da4946e887787e4b04e04..7d36e935046bac94bcab8387031a7af0e82c2cfb
100644
--- a/src/x87/macro-assembler-x87.cc
+++ b/src/x87/macro-assembler-x87.cc
@@ -1935,16 +1935,10 @@ void MacroAssembler::IndexFromHash(Register hash,
Register index) {
// 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.
- and_(hash, String::kArrayIndexValueMask);
- STATIC_ASSERT(String::kHashShift >= kSmiTagSize && kSmiTag == 0);
- if (String::kHashShift > kSmiTagSize) {
- shr(hash, String::kHashShift - kSmiTagSize);
- }
if (!index.is(hash)) {
mov(index, hash);
}
+ DecodeFieldToSmi<String::ArrayIndexValueBits>(index);
}
Index: src/x87/macro-assembler-x87.h
diff --git a/src/x87/macro-assembler-x87.h b/src/x87/macro-assembler-x87.h
index
8f04ac35f57815bc5cde271259d3f1185fe704ec..faa9012a915c9363e141d0f9154fef659c568355
100644
--- a/src/x87/macro-assembler-x87.h
+++ b/src/x87/macro-assembler-x87.h
@@ -478,7 +478,23 @@ class MacroAssembler: public Assembler {
void DecodeField(Register reg) {
static const int shift = Field::kShift;
static const int mask = Field::kMask >> Field::kShift;
- sar(reg, shift);
+ if (shift != 0) {
+ sar(reg, shift);
+ }
+ and_(reg, Immediate(mask));
+ }
+
+ template<typename Field>
+ void DecodeFieldToSmi(Register reg) {
+ static const int shift = Field::kShift;
+ static const int mask = (Field::kMask >> Field::kShift) << kSmiTagSize;
+ STATIC_ASSERT((mask & (0x80000000u >> (kSmiTagSize - 1))) == 0);
+ STATIC_ASSERT(kSmiTag == 0);
+ if (shift < kSmiTagSize) {
+ shl(reg, kSmiTagSize - shift);
+ } else if (shift > kSmiTagSize) {
+ sar(reg, shift - kSmiTagSize);
+ }
and_(reg, Immediate(mask));
}
--
--
v8-dev mailing list
[email protected]
http://groups.google.com/group/v8-dev
---
You received this message because you are subscribed to the Google Groups "v8-dev" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/d/optout.
