Author: [email protected]
Date: Thu Jan 22 04:12:15 2009
New Revision: 1123
Modified:
branches/bleeding_edge/src/assembler-ia32-inl.h
branches/bleeding_edge/src/assembler-ia32.cc
branches/bleeding_edge/src/assembler-ia32.h
Log:
Avoid memmove when emitting operands in the assembler
and get rid of the mutability of the Operand byte buffer.
Review URL: http://codereview.chromium.org/18656
Modified: branches/bleeding_edge/src/assembler-ia32-inl.h
==============================================================================
--- branches/bleeding_edge/src/assembler-ia32-inl.h (original)
+++ branches/bleeding_edge/src/assembler-ia32-inl.h Thu Jan 22 04:12:15 2009
@@ -270,8 +270,7 @@
}
-void Operand::set_modrm(int mod, // reg == 0
- Register rm) {
+void Operand::set_modrm(int mod, Register rm) {
ASSERT((mod & -4) == 0);
buf_[0] = mod << 6 | rm.code();
len_ = 1;
Modified: branches/bleeding_edge/src/assembler-ia32.cc
==============================================================================
--- branches/bleeding_edge/src/assembler-ia32.cc (original)
+++ branches/bleeding_edge/src/assembler-ia32.cc Thu Jan 22 04:12:15 2009
@@ -255,12 +255,6 @@
}
-void Operand::set_reg(Register reg) const {
- ASSERT(len_ > 0);
- buf_[0] = (buf_[0] & ~0x38) | static_cast<byte>(reg.code() << 3);
-}
-
-
bool Operand::is_reg(Register reg) const {
return ((buf_[0] & 0xF8) == 0xC0) // addressing mode is register only.
&& ((buf_[0] & 0x07) == reg.code()); // register codes match.
@@ -2098,10 +2092,18 @@
void Assembler::emit_operand(Register reg, const Operand& adr) {
- adr.set_reg(reg);
- memmove(pc_, adr.buf_, adr.len_);
- pc_ += adr.len_;
- if (adr.len_ >= sizeof(int32_t) && adr.rmode_ != RelocInfo::NONE) {
+ const unsigned length = adr.len_;
+ ASSERT(length > 0);
+
+ // Emit updated ModRM byte containing the given register.
+ pc_[0] = (adr.buf_[0] & ~0x38) | (reg.code() << 3);
+
+ // Emit the rest of the encoded operand.
+ for (unsigned i = 1; i < length; i++) pc_[i] = adr.buf_[i];
+ pc_ += length;
+
+ // Emit relocation information if necessary.
+ if (length >= sizeof(int32_t) && adr.rmode_ != RelocInfo::NONE) {
pc_ -= sizeof(int32_t); // pc_ must be *at* disp32
RecordRelocInfo(adr.rmode_);
pc_ += sizeof(int32_t);
Modified: branches/bleeding_edge/src/assembler-ia32.h
==============================================================================
--- branches/bleeding_edge/src/assembler-ia32.h (original)
+++ branches/bleeding_edge/src/assembler-ia32.h Thu Jan 22 04:12:15 2009
@@ -260,19 +260,19 @@
bool is_reg(Register reg) const;
private:
- // Mutable because reg in ModR/M byte is set by Assembler via set_reg().
- mutable byte buf_[6];
+ byte buf_[6];
// The number of bytes in buf_.
unsigned int len_;
// Only valid if len_ > 4.
RelocInfo::Mode rmode_;
- inline void set_modrm(int mod, // reg == 0
- Register rm);
+ // Set the ModRM byte without an encoded 'reg' register. The
+ // register is encoded later as part of the emit_operand operation.
+ inline void set_modrm(int mod, Register rm);
+
inline void set_sib(ScaleFactor scale, Register index, Register base);
inline void set_disp8(int8_t disp);
inline void set_dispr(int32_t disp, RelocInfo::Mode rmode);
- inline void set_reg(Register reg) const;
friend class Assembler;
};
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