AMD AMD5K86 - Page 5

AMD~
AMD51(fJ6 Processor Technical Reference Manual
18524BjO-Mar1996
3 Software Environment and Extensions 3-1
3.1 Control Register 4 (CR4) Extensions ..................... 3-2
3.1.1 Machine-Check Exceptions ................ ; .......... 3-4
3.1.2 4-Mbyte
Pages ...................................... 3-5
3.1.3 Global
Pages .......•................................ 3-9
3.1.4
Virwal-8086 Mode Extensions (VME) ................. 3-12
Interrupt Redirection in Virtual-8086 Mode Without
VME Extensions ................................... 3-12
Hardware Interrupts and the VIF and VIP Extensions .... 3-13
Software Interrupts and the Interrupt Redirection
Bitmap (IRB) Extension ............................. 3-21
3.1.5
Protected Virtual Interrupt (PVI) Extensions ........... 3-24
3.2 Model-Specific Registers (MSRs) ....................... 3-25
3.2.1 Machine-Check Address Register (MCAR) ............. 3-25
3.2.2
Machine-Check Type Register (MCTR) ................ 3-26
3.2.3
Time Stamp Counter (TSC) .......................... 3-27
3.2.4
Array Access Register (AAR) ........................ 3-27
3.2.5
Hardware Configuration Register (HWCR) . . . . . . . . . . . . . 3-28
3.3 New Instructions .................................... 3-28
3.3.1 CPUID ............................................ 3-29
3.3.2 CMPXCHG8B
...................................... 3-32
3.3.3
MOV to and from CR4 .............................. 3-33
3.3.4 RDTSC
............................................ 3-34
3.3.5 RDMSR
and WRMSR ............................... 3-35
3.3.6 RSM
............................................. 3-37
3.3.7
lllegal Instruction (Reserved Opcode) ................. 3-38
4 Performance 4-1
4.1 Code Optimization .................................... 4-1
4.1.1 General Superscalar Techniques ....................... 4-1
4.1.2 Techniques Specific to the AMD5
K
86 Processor .......... 4-3
4.2 Dispatch and Execution Timing ......................... 4-5
4.2.1 Notation ........................................... 4-5
4.2.2 Integer Instructions .................................. 4-8
4.2.3 Integer Dot Product Example .. ; ..................... 4-17
4.2.4
Floating-Point Instructions ........................... 4-19
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